Dawgs head gasket chronicles
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URL: http://www.westcoastfieros.com/forum/forum_posts.asp?TID=2120
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Topic: Dawgs head gasket chronicles
Posted By: Dawg
Subject: Dawgs head gasket chronicles
Date Posted: 06 October 2010 at 4:57pm
OK.....It's head gasket time. Here we go.
This is our baby with her top off.....:)
While I'm at it, may as well spiffy things up a bit. I'm trying to stick with our Gold on Black theme. Here's the before.
And the after. I like it.
I'm going to do the Upper Plenum in the same color scheme after I give it and the Throttle Body the big bore treatment.
Should look grand....eh?
The Dawg
------------- You dream it up....I'll make it
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Replies:
Posted By: Dawg
Date Posted: 06 October 2010 at 8:00pm
Just got the heads back after getting them resurfaced. I still have to lap the valves in and install new stem seals. Then give everything a good cleaning before mounting the heads.
I hope I can find my valve compressor.
Happy days.......
The Dawg
------------- You dream it up....I'll make it
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Posted By: Patrick
Date Posted: 06 October 2010 at 8:06pm
Damien, since you have the heads off...
Have a look http://somender-singh.com/content/view/7/31/ - Here for some free horsepower and better fuel economy.
Seriously, it's worth at least investigating.
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Posted By: Romeo
Date Posted: 06 October 2010 at 8:24pm
Hmm... I don't know about that, will have to investigate further. On the tried and true front, are you going to port and polish (Or swirl-cut) the heads while they're off?
------------- Never shift into reverse without a back-up plan.
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Posted By: Capt Fiero
Date Posted: 06 October 2010 at 10:12pm
Patrick wrote:
Damien, since you have the heads off...
Have a look http://somender-singh.com/content/view/7/31/ - Here for some free horsepower and better fuel economy.
Seriously, it's worth at least investigating.
|
Pat that is one hell of an interesting article. I am definitely going to look into that mod. If it really works, I would be tempted to pull all my Fiero V6 heads even my Caddy heads, do that mod and then save the heads to increase compression and really take advantage of it.
------------- Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.
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Posted By: Dawg
Date Posted: 06 October 2010 at 10:40pm
The theory seems like it would work. My only concern would be stress risers forming around the sharp edges. i would smooth things over a little more if I was to try it.
Not with this engine however.
The Dawg
Patrick wrote:
Damien, since you have the heads off...
Have a look http://somender-singh.com/content/view/7/31/ - Here for some free horsepower and better fuel economy.
Seriously, it's worth at least investigating.
|
------------- You dream it up....I'll make it
|
Posted By: Dawg
Date Posted: 06 October 2010 at 10:52pm
Nope. I just don't have the time to get fancy. This is a daily driver that needs to get back on the road.
Having said that. I will be modifying the upper plenum quite a bit including some gasket matching between plenums. Also going to big bore the TB while it's out. That should broaden the power curve.
I was also going to put a variable fuel regulator and gauge but getting low on cash. I've spent a lot of money on my truck in the last month or so.
If I hustle, I could get it going in a day. But I think I'm going to take my time and double check everything as I go. Need to paint too of course.
The Dawg
Romeo wrote:
Hmm... I don't know about that, will have to investigate further. On the tried and true front, are you going to port and polish (Or swirl-cut) the heads while they're off? |
------------- You dream it up....I'll make it
|
Posted By: Patrick
Date Posted: 06 October 2010 at 11:52pm
Capt Fiero wrote:
Patrick wrote:
Have a look http://somender-singh.com/content/view/7/31/ - Here for some free horsepower and better fuel economy.
|
Pat that is one hell of an interesting article. I am definitely going to look into that mod.
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Thought you guys would find it interesting.
Yeah, if I was removing a head for any reason, I think I'd be tempted to try that simple modification out.
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Posted By: Romeo
Date Posted: 07 October 2010 at 12:32am
I'd try it on the irons, 'cause if they ever go to hell after, I could switch over to the Brodix heads.
------------- Never shift into reverse without a back-up plan.
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Posted By: CFoss
Date Posted: 07 October 2010 at 8:28am
That is pretty cool. It looks like about a cutting disk width to me! It's tempting to try. Anyting to reduce the likelihood of detonation as I move to the turbo.
The gasket match is pretty easy obviously. When I did my intake, I went further, and removed a large amount of material around the injector entrance. This aparently allows a better spray pattern from the injector, and better airflow. Leave the fin; I'm pretty sure it routes the air around the valve stem and improves performance.
Chay
------------- 86 SE 3.4
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Posted By: Romeo
Date Posted: 07 October 2010 at 1:26pm
Let me know how it goes. I understand the logic in that, but I'm extremely skeptical. Manufacturers dedicate HUGE money into develloping heads (Superceded only by the block and PCM in terms of cost-to-devellop), even going to far as to C'n'C cut aluminum these days. If something so simple made that large a difference, I'd be willing to bet they'd be doing it already.
------------- Never shift into reverse without a back-up plan.
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Posted By: Dawg
Date Posted: 07 October 2010 at 2:15pm
Also, have a good look at the heads I just got done. The flat "shelf" that presumably is shielding fuel from the wave front is very tiny. So at least in this case, it doesn't seem worth doing even if it does work.
On a V8 head however, there can be a much bigger shelf present. Especially high compression varieties.
As much as I like to support free thinking and new ideas I agree with Tristan on this one. Seems highly unlikely that hundreds of engineers would miss something like this. I have never seen such grooves on any head before.
The Dawg
------------- You dream it up....I'll make it
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Posted By: Dawg
Date Posted: 07 October 2010 at 5:54pm
Ok....who wrote these Fiero manuals anyway?
I just looked up the torque specs for the head bolts and they say 65-90 FT-LBS. Huh?
Ok.....I choose 90.....what do I win?
And does anyone have a valve compressor I can borrow? I looked all over and can't find mine. It's one of those tools that you need every blue moon but are screwed if you don't have one.
Thanks,
The Dawg
------------- You dream it up....I'll make it
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Posted By: Dr.Fiero
Date Posted: 07 October 2010 at 7:31pm
^ Yeah, I've got one (a decent one at that)
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Posted By: Romeo
Date Posted: 07 October 2010 at 9:22pm
It means torque them in sequence to 65ft-ibs first, then go through and re-torque them all to 90ft-ibs.
Realistically, 90ft-ibs off the get go should be fine.
------------- Never shift into reverse without a back-up plan.
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Posted By: Dawg
Date Posted: 07 October 2010 at 9:39pm
Great, I'll phone ya tomorrow morning.
Thank you.
The Dawg
------------- You dream it up....I'll make it
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Posted By: Capt Fiero
Date Posted: 10 October 2010 at 11:29pm
I usually start at 40lbs, or even just hand spin them in / use a drill on tow torque setting. Then go to 40lbs, 60lb, 90lbs, then a final 95 or 100lbs. to finish up. I have not had a head gasket fail yet. Also not that your engine is not a Fiero motor, and you should double check the specs with a book for your exact engine, it may have a higher torque spec, also make sure to use loads of head bolt sealant, The white goopy stuff.
------------- Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.
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Posted By: Dawg
Date Posted: 11 October 2010 at 12:31am
I'm sure the Fiero specs will work just fine. The heads are the same and I bought "Fiero" bolts. I did go 40 60 90 BTW.
I put the thread sealant on all the bolts whether they needed it or not. Only half the head bolts go into the water jacket. I did this to keep the torque even across the head. Even pressure is WAY more important than the actual torque rating itself. Obviously too low is bad but too high can cause problems also.
Things are slowly progressing. With all the painting and repairs as I go, it should be a few more days before she's running.
The Dawg
------------- You dream it up....I'll make it
|
Posted By: Dawg
Date Posted: 11 October 2010 at 4:59pm
More progress. The intake is on.
Disabling the cold start injector is a mod that many do to their engines while they're in there. This is what it looks like. Notice I cut the metal fuel line and crimped it over. At the other end is the fuel rail opening. You have to plug that up too.
Here is a sh*tty picture of the tool I made to clean out the head bolt threads. The threads on this motor are M11X1.5. Rare thread, not easy to find this tap. So rather than do that I made a clean out tool from an old head bolt. I ground a couple flutes along the threads so capture any gunk as I ran the tool in and out of the threaded holes.
Worked perfectly and cost nothing....except a new set of head bolts which I had decided to buy anyway.
Now it's time to install the push rods and adjust the rockers.
Hopefully I'll be modifying the upper plenum tonight if all goes well.
The Dawg
------------- You dream it up....I'll make it
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Posted By: Dr.Fiero
Date Posted: 11 October 2010 at 9:51pm
The fitting in the fuel rail for the cold start - it's the same as a japanese car's oil drain plug. I can never remember which one, but... pull it out, and take it to Lordco. Look at the Papco rack of drain plugs and you'll be able to match it up.
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Posted By: Capt Fiero
Date Posted: 12 October 2010 at 9:36am
Looking good Dawg. I'll let you in on a little secret about the CSV later.
------------- Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.
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Posted By: Dawg
Date Posted: 12 October 2010 at 6:53pm
Didn't get the valve covers on today as hoped. But decided to make the upper plenum pretty instead.
Man, there's a lot of nooks and crannies on this darn part. All the cleaning and prep work and multiple coats of paint. It took way too long......Oh well, it turned out great!
I did the big bore treatment too so I guess that's not too bad then.
It's going to look pretty fancy once it's all assembled.
The Dawg
------------- You dream it up....I'll make it
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Posted By: Dawg
Date Posted: 12 October 2010 at 6:58pm
Thanks buddy. I finally get to have one of my own modified intake systems. Yahoo!
CSV? Cold Start Valve?
The Dawg
Capt Fiero wrote:
Looking good Dawg. I'll let you in on a little secret about the CSV later. |
------------- You dream it up....I'll make it
|
Posted By: Dawg
Date Posted: 14 October 2010 at 4:55pm
More progress.
Adjusted the rockers (Couldn't find the info you suggested John).
Installed valve covers and lower plenum.
It's starting to look like something again.
The Dawg
------------- You dream it up....I'll make it
|
Posted By: Dr.Fiero
Date Posted: 14 October 2010 at 5:06pm
Dawg wrote:
Adjusted the rockers (Couldn't find the info you suggested John).
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From the site:
Setting Hydraulic Lifter Pre-load (Adjustable Valve Train) With an adjustable valve train,
proceed as follows:
Install the pushrods and rocker arms. Be sure the pushrods are seated
correctly in the lifter and rocker arm. Turn the engine over in the
direction of rotation until the EXHAUST pushrod just begins to move
upward, opening the valve. Now adjust the INTAKE rocker of that
cylinder. Carefully tighten the nut on the intake rocker while spinning
the pushrod with your fingertips. You will feel a slight resistance in
the pushrod when you have taken up all of the clearance. This is “zero
lash.” Turn the adjusting nut to the specified pre-load – typically
1/4-3/4 of a turn, but this will vary based on the lifter number.
Turn the engine in its rotation direction until the intake pushrod comes
all the way up and almost all the way back down. Now set the EXHAUST
rocker to “zero lash” and add the specified pre-load. Repeat this
process for all remaining cylinders.
(guess it's too late now though)
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Posted By: Dawg
Date Posted: 14 October 2010 at 7:55pm
Yup.....ended up just doing the book method.
But the info is here now.
The Dawg
Dr.Fiero wrote:
(guess it's too late now though)
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------------- You dream it up....I'll make it
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Posted By: kharmata
Date Posted: 15 October 2010 at 2:16pm
Could you guess I really like the Silver on Gold look. No
duh! Looking good.
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Posted By: Dawg
Date Posted: 15 October 2010 at 4:28pm
Thanks. It did turn out great.
Almost done now! Just a few bits here and there and it's time to start it up. If I had had the chance to work on it all day it would be running. But we need to go to a birthday party so tomorrow will have to do.
The biggest thing left to do is finish the big bore throttle body. Lots of hand fitting the butterfly valve left to do.
The Dawg
------------- You dream it up....I'll make it
|
Posted By: Patrick
Date Posted: 15 October 2010 at 5:01pm
So, do we all get trips around the block to feel the difference?
Good job!
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Posted By: kharmata
Date Posted: 15 October 2010 at 6:15pm
Now the big red dog bone will stand out like a sore thumb. Sheesh sounds like something Tristan would say.
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Posted By: Patrick
Date Posted: 15 October 2010 at 7:05pm
kharmata wrote:
Now the big red dog bone and coil will stand out like sore thumbs. |
Fixed that for you.
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Posted By: Dr.Fiero
Date Posted: 15 October 2010 at 7:07pm
Just my opinion (for whatever that's worth!) - fill in the "FIERO" with gloss black enamel.
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Posted By: Patrick
Date Posted: 15 October 2010 at 7:15pm
kharmata wrote:
Now the big red dog bone and the coil and the word "Fiero" will all stand out like sore thumbs. |
Fixed that some more for you.
Sorry Damien, we're a bad bunch.
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Posted By: Capt Fiero
Date Posted: 15 October 2010 at 7:23pm
Na keep the red and add some nice red wires. IMHO its the blue wires that are the odd duck in the stack.
------------- Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.
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Posted By: kharmata
Date Posted: 15 October 2010 at 8:59pm
Posted By: Dawg
Date Posted: 15 October 2010 at 10:05pm
Hahahaha....you guys!
As a matter of fact, Michelle was wanting the Fiero black also but I said I would try it red. Red being my favorite color of course.
The thick layer of clear coat just makes everything gleam. It's way better in person.
Hopefully I'll make it to a meeting some time this century to show it off.
The Dawg
------------- You dream it up....I'll make it
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Posted By: Dawg
Date Posted: 15 October 2010 at 10:17pm
As long as we get to swap cars....:)
Fear not, I will be reporting my findings in detail. I'm expecting the performance cam will really bring out the best of this big bore mod. The timing wasn't right for the variable fuel regulator which is too bad. Maybe this spring.
Thanks, it turned out better than I imagined it would.
Patrick wrote:
So, do we all get trips around the block to feel the difference?
Good job!
|
------------- You dream it up....I'll make it
|
Posted By: Romeo
Date Posted: 16 October 2010 at 1:16am
Posted By: Dawg
Date Posted: 16 October 2010 at 8:07pm
Good news my homies! She started up just fine with no issues. I don't have a timing light so I set things up by ear for now. It certainly sounds different that's for sure. I punched the throttle and with no air cleaner it whoops good.
Here's totally finished just about to start.
I made a short video but it's way too big to upload. I'll try and figure something out.
Happy Days!
The Dawg
uploads/Dawg/2010-10-16_225013_first_start-small.mov - 2010-10-16_225013_first_start-small.mov
------------- You dream it up....I'll make it
|
Posted By: Dawg
Date Posted: 17 October 2010 at 5:28pm
Ok....the car has been taken on it's maiden voyage and WOW, what a difference. I am amazed how this has changed the throttle response. More bottom end for sure and that sound....yummy. Sounds more throaty, like it's gonna bite someone.
Top end? That will have to wait till I get everything tuned up. It always seemed like it wanted to go faster before, now even more so.
On another note, I'm still having some cooling issues. I've spent the better part of 2 hours "burping" this thing. I go for a run and come home and open the engines rad cap. The first few times it spewed a fair bit before calming down. The last time I did it, it just barely burped and nothing else.
I've got it to the point now where it keeps the car nice and cool for about 10 minutes or so and then the gauge rises into the red quickly then after 10-20 seconds drops right back down.
I've checked for bubbles in the water, there are non to speak of. The odd gurgle if I shake the car back and forth. I've purchased a new water pump just in case. If I can get this sorted out I'll bring it back.
So I know Dave has said he's seen this sort of thing before and that it's vapor lock of some sort. Anyone have any ideas on how to get it all out?
I'm thinking of parking the car with the front up hill and burping the radiator a few times.
Any suggestions would be great.
Thanks,
The Dawg
------------- You dream it up....I'll make it
|
Posted By: kharmata
Date Posted: 17 October 2010 at 5:31pm
The owners manual for mine calls for a specific filling procedure. It has worked for me. Also if you still need I have a timing light.
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Posted By: Dr.Fiero
Date Posted: 17 October 2010 at 5:35pm
Shouldn't take more than 1 or 2 burps and 10 minutes.
Car level (or nose DOWN slightly). Front cap off, back cap off, t-stat OUT. Slowly fill from rear until you get a non foamy/bubbly/whatever stream from the front cap. Slap on front cap right away. (make sure you've got the right front cap! Most books list the wrong one. The 'dingle valve' in the cap should be spring loaded CLOSED, not able to dangle loose) Top off at the rear. Slap on cap tight. Run for about 1 minute. Remove rear cap slowly with a towel wrapped around the neck (saves slopping A/F on your belts!). Top up as required, then wait a minute for it to all settle. Replace rear cap, re-run, check, top up. Repeat as required. When nothing changes, stuff in T-stat (lube the o-ring!) and replace cap one last time.
Hit the road and enjoy.
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Posted By: Patrick
Date Posted: 17 October 2010 at 6:02pm
Dawg wrote:
I'm thinking of parking the car with the front up hill and burping the radiator a few times. |
Not a good plan. You've got it backwards.
Just do what John said.
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Posted By: Dawg
Date Posted: 18 October 2010 at 7:43pm
Success! After moving the car to a more level part of the yard, I did the prescribed method of "burping" and all is well.
Well, sort of. I bought a low temp fan switch from the Fiero Store a while back and the darn thing is basically on all the time. It comes on after a few minutes of idling and never turns off.
So you can imagine the result. It's running too cold. I also have a 180 deg thermostat in there. I will try and put the 195 deg thermostat back in to see where it levels off.
As far as performance goes, I'm still at the WOW stage....:) As I suspected, the performance cam just loves it's new intake. The car seems to pull hard all the way to where I get scared for it's life. Which at the moment is about 6000 rpm. I say about, because my tach is reading too high.
The engine sound up there is fantastic.
EVERYONE with a 60deg V6 should do this, honestly. If we could ever get enough club members interested, I would come up with a good group rate for this intake combo. Also, maybe I do the hard stuff and leave out the cleanup and painting. Then we all get together for a tech day and I show everyone how to detail their own plenums.
The Dawg
------------- You dream it up....I'll make it
|
Posted By: Dr.Fiero
Date Posted: 18 October 2010 at 8:14pm
By next spring (ish) I'm hoping to get back to work on my red car.
I'll be hunting you down for a manifold and TB then. If you think it's
that much better with just a cam, think what it'll be like with the turbo
(that was fast before!).
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Posted By: Dawg
Date Posted: 18 October 2010 at 11:16pm
I think this is one of those mods that amplifies the results from other mods, if you get my meaning. Because it's situated at the beginning of the engine, it has a profound impact on whatever comes next.
So yes, I can just imagine what it would do for your engine.
If I had to put a number on it, I would estimate I've gained at least 15Hp. But it's the throttle response that has changed the most.
Dr.Fiero wrote:
By next spring (ish) I'm hoping to get back to work on my red car.
I'll be hunting you down for a manifold and TB then. If you think it's
that much better with just a cam, think what it'll be like with the turbo
(that was fast before!).
|
------------- You dream it up....I'll make it
|
Posted By: Capt Fiero
Date Posted: 19 October 2010 at 7:12am
I think I mentioned to you, that it was the part throttle acceleration that I noticed so much, car would just zoom up to speed and rpms climbed so much easier without struggling. Made the car feel more Zippy and Fun to drive. If someone has a totally stock engine, they could always swap the rockers to a good set of 1.6 ratio rockers while they have the top end apart. Would help a fair bit getting the air in and out, however if the manifolds have not been ported, no mode in the world is going to help. So make sure your customers know, that if they install this on a car with non ported manifolds, don't go crying foul if they don't see massive changes.
Personally I really like the one on my 88GT, it really woke it up, Colby's Dad, took a ride in my car and commented on how quick it was.
Another recommendation if the people don't want to go to all the stuff like adjustable FPR and O2 meter on the dash, they can always just find a set of good 17# injectors and swap in. The stock ECM can handle them just fine and will give a great boost in fuel in the higher rpm ranges.
P.S. the stock 15# injectors that are now 20+ years old, are probably performing like new 12# injectors, just a side note to think about. The stock 15# injectors when new and in perfect condition can only support 200hp, so the worn out ones will do maybe 160hp. (fine for a stock motor, however getting dangerous on a modded motor.)
Dawg, I have a spare Autometer Air Fuel Ratio gauge here if you want to hook it up and run around with it for a few days. Very simple wire up. Power / Ground, plus 1 wire that taps into the ECM / O2 sensor feed in the cabin. Its no wide band, but it gets the job done to see if you are not staying full rich at WOT high rpms.
------------- Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.
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Posted By: kharmata
Date Posted: 19 October 2010 at 9:02am
I wanna do mine with manifolds, intake and injectors but
also likely need rings - then might as well do bearings, oh
and a clutch too. Who's up for some overhaulin?
(i can delete this after you've all heard my whining )
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Posted By: Dawg
Date Posted: 19 October 2010 at 5:11pm
Ideally, there would be a home grown way of simply cleaning/servicing the injectors we already have.
What kind of money is involved in buying new ones BTW?
As for the air/fuel gauge, I think it would be better to wait till I have a variable regulator to play with. Where do you get this regulator locally?
For now though, can't I get any useful info from my OBD1 reader?
The Dawg
Capt Fiero wrote:
P.S. the stock 15# injectors that are now 20+ years old, are probably performing like new 12# injectors, just a side note to think about. The stock 15# injectors when new and in perfect condition can only support 200hp, so the worn out ones will do maybe 160hp. (fine for a stock motor, however getting dangerous on a modded motor.)
Dawg, I have a spare Autometer Air Fuel Ratio gauge here if you want to hook it up and run around with it for a few days. Very simple wire up. Power / Ground, plus 1 wire that taps into the ECM / O2 sensor feed in the cabin. Its no wide band, but it gets the job done to see if you are not staying full rich at WOT high rpms. |
------------- You dream it up....I'll make it
|
Posted By: Dawg
Date Posted: 19 October 2010 at 5:29pm
The beauty of all this is most of what you just mentioned involves bolt on goodies. Goodies that can be moved to another block if need be. So nothing is lost by doing the mods to this block, even if in the end it lets you down.
Well, I can help you with the ported exhaust manifolds, TB and intake. If you were to do them all at once there would be a very noticeable difference.
PM me.
The Dawg
kharmata wrote:
I wanna do mine with manifolds, intake and injectors but
also likely need rings - then might as well do bearings, oh
and a clutch too. Who's up for some overhaulin?
(i can delete this after you've all heard my whining )
|
------------- You dream it up....I'll make it
|
Posted By: Capt Fiero
Date Posted: 19 October 2010 at 5:46pm
Dawg wrote:
Ideally, there would be a home grown way of simply cleaning/servicing the injectors we already have.
What kind of money is involved in buying new ones BTW?
As for the air/fuel gauge, I think it would be better to wait till I have a variable regulator to play with. Where do you get this regulator locally?
For now though, can't I get any useful info from my OBD1 reader?
The Dawg
Capt Fiero wrote:
P.S. the stock 15# injectors that are now 20+ years old, are probably performing like new 12# injectors, just a side note to think about. The stock 15# injectors when new and in perfect condition can only support 200hp, so the worn out ones will do maybe 160hp. (fine for a stock motor, however getting dangerous on a modded motor.)
Dawg, I have a spare Autometer Air Fuel Ratio gauge here if you want to hook it up and run around with it for a few days. Very simple wire up. Power / Ground, plus 1 wire that taps into the ECM / O2 sensor feed in the cabin. Its no wide band, but it gets the job done to see if you are not staying full rich at WOT high rpms.
|
|
If you try to buy "NEW" GM Injectors, its about $2400 bucks. Yes Twenty Four Hundred, however,
You can get replacement injectors from Ebay for less than a hundred bucks for a set of 8 from a Ford Mustang. Yes they are a direct bolt in. Brian runs 19# Mustang Injectors on his 3.2 with a custom chip and adjustable regulator. As for the regulator, Mopac should have them in stock as they are used on I believe LS1 Camaro's.
------------- Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.
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Posted By: Dr.Fiero
Date Posted: 19 October 2010 at 7:28pm
If you want to get your existing ones serviced (assuming they're not fubared) it's about $300 taxes in. I had mine done by a place in port kells.
All flow tested, cleaned, test report, bla bla.
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Posted By: Dawg
Date Posted: 20 October 2010 at 9:06pm
Ok....I'm driving home from Dave's place tonight on the freeway just cruising. I step on the gas a bit to pass a guy and the motor backfires once or twice and gets sluggish. I go back into my lane and roll along for a while thinking "don't leave me stranded on the freeway at night you dirty Bitch". It goes along just fine as long as I'm just touching the pedal a tiny bit. I get closer to home and decide to punch it again and it backfires a couple more times and then seems to run ok the rest of the way home......Huh?
We just did the timing and it was running perfect.
Most likely place to start? Ignition I'm guessing. Bad connection somewhere. Loosing spark then way too rich so backfire.
Any ideas?
The Dawg
------------- You dream it up....I'll make it
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Posted By: Dr.Fiero
Date Posted: 20 October 2010 at 9:11pm
Sounds like somethings up with the map sensor or the tps. They'd
both do that.
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Posted By: Capt Fiero
Date Posted: 20 October 2010 at 9:11pm
Double check the dist hold down bolt.
------------- Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.
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Posted By: Dawg
Date Posted: 20 October 2010 at 10:08pm
Ok....I'll hook up my code reader tomorrow and do more driving. There was no engine light so I'm assuming the sensors are still sending some sort of signal. Is this ECM advanced enough to detect "out of range" errors.
The Dawg
------------- You dream it up....I'll make it
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Posted By: Dawg
Date Posted: 21 October 2010 at 9:41pm
No progress on the car today other than a nice fresh oil change.
Tim's engine surgery took quite a while.
I'm going to try and advance the ignition a little bit to see what happens.
The Dawg
------------- You dream it up....I'll make it
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Posted By: CFoss
Date Posted: 22 October 2010 at 9:51am
You gotta check the map and tps. More the map I would think, because the tps doesn't matter in steady state throttle(It's used for enrichment). In other words, it would kick up a fuss when you hit it due to lack of fuel, but would run right after a short time at that throttle setting.
Also, do you run a CAT? It could have self destructed (blocked).
Chay
------------- 86 SE 3.4
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Posted By: Patrick
Date Posted: 22 October 2010 at 10:18am
CFoss wrote:
Also, do you run a CAT? It could have self destructed (blocked). |
Good point. That's what happened to my GT as reported http://www.westcoastfieros.com/forum/forum_posts.asp?TID=956&KW - Here .
Patrick wrote:
I also can't emphasize how gutless the GT is once the revs go up. It starts fine, runs smooth, and responds okay off the line, but there's no power if I rev it over, say 3000 RPM. When I kick it down into second gear on the freeway while doing 50-60 mph, all that happens basically is more intake noise. |
Damien, while standing at the back of the car, rev the crap out of the engine (literally) and look for a fine white power to come shooting out of the tail pipes.
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Posted By: Dawg
Date Posted: 22 October 2010 at 11:11am
TPS seemed fine and I believe the MAP was within normal range when we put the scanner to it. I was going to drive around today watching my scanner but it decided to stop working last night. One more thing to try and fix....
As for the CAT being blocked I highly doubt it. The engine is putting out so much power right now that it couldn't be blocked. Besides, it's less than a year old.
Last night we had to drive to North Van to drop off the van Michelle was borrowing. The car ran perfect till I decided to see how fast I could go up "the cut". Well I jammed out at 150 but the motor could have done more. Hey! There were other motorists about.
Shortly after that it started hesitating. By the time I got close to home on the freeway, it was getting really bad. You would push on the gas pedal and it would buck and hesitate badly. If you punched it it would go but not smoothly. It never back fired last night but I bet if I would have continued driving it would have gotten worse.
So it looks like there's a heat related component to this.
There's no codes or anything obvious going on.
Will keep digging.
The Dawg
CFoss wrote:
You gotta check the map and tps. More the map I would think, because the tps doesn't matter in steady state throttle(It's used for enrichment). In other words, it would kick up a fuss when you hit it due to lack of fuel, but would run right after a short time at that throttle setting.
Also, do you run a CAT? It could have self destructed (blocked).
Chay |
------------- You dream it up....I'll make it
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Posted By: Dr.Fiero
Date Posted: 22 October 2010 at 11:18am
Patrick wrote:
rev the crap out of the engine (literally) and look for a fine white power to come shooting out of the tail pipes. |
If it DOES start to do this, make sure you wrap baggies around the tail pipes right away, and then carefully store the contents. It would seem that THAT is where I left my stash of coke.
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Posted By: Dr.Fiero
Date Posted: 22 October 2010 at 11:20am
Dawg wrote:
TPS seemed fine |
That's what I thought too on my black car.
Remember me being in the parking lot at Arlington with a scan tool... trying to figure out why it was bucking and kicking one moment, then fine, then whacked?
My TPS (which usually scanned fine) was f'd. Replaced it - problem gone. No guarantees that's YOUR issue, but....
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Posted By: Patrick
Date Posted: 22 October 2010 at 3:23pm
Dawg wrote:
So it looks like there's a heat related component to this. |
Try doing http://www.westcoastfieros.com/forum/forum_posts.asp?TID=949&KW - This . Worked for me.
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Posted By: Romeo
Date Posted: 22 October 2010 at 5:04pm
Dr.Fiero wrote:
Dawg wrote:
TPS seemed fine |
That's what I thought too on my black car.
Remember me being in the parking lot at Arlington with a scan tool... trying to figure out why it was bucking and kicking one moment, then fine, then whacked?
My TPS (which usually scanned fine) was f'd. Replaced it - problem gone. No guarantees that's YOUR issue, but....
| I remember that! We were in the Safeway parking lot...
------------- Never shift into reverse without a back-up plan.
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Posted By: Dawg
Date Posted: 16 January 2011 at 10:52pm
I never updated this thread so here goes.
The problem ended up just being timing. We did the timing in the bright sunshine and it was hard to see. The balancer had not been cleaned either.
It ended up needing some advancement.
The Dawg
------------- You dream it up....I'll make it
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