sporadic ideal and power surge
Printed From: West Coast Fieros
Category: Technical Topics Forum
Forum Name: Technical Questions and Discussions
Forum Description: Got a technical question about your fiero? ask it here.
URL: http://www.westcoastfieros.com/forum/forum_posts.asp?TID=3155
Printed Date: 22 November 2024 at 11:52am
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Topic: sporadic ideal and power surge
Posted By: minidonutman
Subject: sporadic ideal and power surge
Date Posted: 16 March 2013 at 6:43pm
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power
Hello I'm having ongoing problems with our 86 V-6 GT it seams to run along good then all sudden at a stop the rpm will bounce around from 1450 down to 300 almost a stall out it will also when driving along in 3 or 4th all of a sudden feel like a pow er ban will kick in and the power is awesome. I put it in a shop they replaced the comouter and changed out the distributor (completely new) also changed all filters and fluids it still was doing same thing so they sai it was our exhaust so they replaced it from manifold back all new (cat,pipe,muffler) now still doing same but also some new things like turn signal reversed they said that would fix it's self once the computer relearns. We've put over $3500.00 into repairs last month with no resolve can anyone shed some light or tell me where to take it to have it fixed. This is suposto be a car for my son and me to enjoy together and sofar all we've shared is a depressing feeling looking at it and not enjoying the ride. Please help thank 
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Replies:
Posted By: Patrick
Date Posted: 16 March 2013 at 8:58pm
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Canada is large country. How far you willing to go?
Was the ignition coil checked/replaced? How about the tach filter? You haven't mentioned the fuel pump either. What kind of fuel pressure is being produced?
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minidonutman wrote:
Total BS. 
Posted By: minidonutman
Date Posted: 16 March 2013 at 9:12pm
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They checked pressure it was good we did not replace ignition coil yet
was just looking on line at MSD one at Lordco. We live in Port Coquitlam BC. Not sure what the Tach filter is but they said all filters were changed fuel filter was changed. |
Posted By: Patrick
Date Posted: 16 March 2013 at 10:22pm
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That doesn't tell us much. What was the fuel pressure? The 2.8 V6 needs about 3x the fuel pressure that the 4-cyl 2.5 engine requires.
Lots to read over http://www.fierosearch.com/cgi-bin/search.cgi?start=1&forum=-1&where=SUB&SearchQuery=tach+filter&Action=DoSearch&datesort=D - Here . One thread in specific may answer your questions - http://www.fiero.nl/forum/Archives/Archive-000001/HTML/20010116-2-004344.html - What's the deal with Tach Filter!?!? (car runs bad with it) Care to mention where you had your Fiero worked on so everyone here can avoid the place? I don't think they had a clue what they were doing, except perhaps trying to empty your bank account.
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Posted By: minidonutman
Date Posted: 16 March 2013 at 10:35pm
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Not sure to be honest what the pressure was it
was worked on at Tremblay motors in Vancouver they were nice people but I would guess not to familiar with the Feiro. Who do you or people in the club use I'd be more then happy to take it to them. |
Posted By: Patrick
Date Posted: 16 March 2013 at 10:42pm
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The truth is... Most of us who are long term owners of Fieros have learned to do most everything ourselves on our own cars. It's the only way when owning 25-29 year old vehicles not to be taken advantage of by automotive repair shops on a regular basis. Even the "honest" ones don't seem to know their way around these cars anymore. Those links I supplied to you in my last post are from http://www.fiero.nl/cgi-bin/fiero/Ultimate.cgi?action=intro - Pennock's Fiero Forum . Spend some time there and you'll learn everything there is to know about our favorite little plastic cars.
Don't waste your money on an MSD coil, especially from a place like Lordco. Get a good used OEM coil (if you need one) from the wreckers. I like http://www.pickapart.ca/ - Pick-a-Part in Chilliwack (although there are handier wreckers). GM used this coil on many different vehicles. No shortage of them to be found.
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Posted By: minidonutman
Date Posted: 16 March 2013 at 11:10pm
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thank you that that really helps my son and I
are trying to do as a project together so we don't mind learning together. Ill go check out pick a part they are the one with the pink dusOseter out front..dose the hole turn signal thing with the computer needing to relearn make cents. Also would pick a part be a good place for seats or would you order from the West coast on line store in California..have you been a club member for long I'd like to join with my son |
Posted By: Patrick
Date Posted: 16 March 2013 at 11:27pm
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Yes, it's on the left (north) side of the freeway as you're going east.
As mentioned previously, that is total nonsense. The ECM has nothing to do with the turn signals.
Sure, if they have any that are suitable. Bucket seats go on special there every few weeks (including this week) for $19.95, but currently there are no Fieros at Pick-a-Part (if it's actual Fiero seats you want).
I joined this club originally in 2008, but not all of us who post on the club forum necessarily go to club meetings (although you and your son should check out a meeting). At Pennock's I've been a member since it's inception in 1999. I was about the 50th to 60th person to sign up. Now there are currently 22,841 registered members at Pennock's.
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Posted By: CFoss
Date Posted: 18 March 2013 at 10:33am
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Back to your problem. I would have guessed based on the symptoms that you had a paritally clogged muffler (Form the cat converter dying and ejecting material into it). However, you said you are new from the manifolds back, so that has been dealt with. Your idle symptoms could also be a EGR stuck open. An egr is a exhaust recirculation valve which opens to allow exhaust gasses into the intake stream to cool the combustion process and lower nox production. in other words, it's pollution control. At idle it should be closed, but sometimes they stick open causing poor/rough idle. To check it I usually pull it off and block the entrance with a plate, then run the car and see if there is any difference.When you're in there, check for a cracked egr tube, which is a classic failure on the Fiero. It could also be a failing vaccuum tube, especially theone feeding the map sensor. This would cause no end of poor running. It doesn't quite fit your symptoms though. If that's good, that leaves you with the big 3. 1) Compression 2) Fuel 3) Spark, and spark advance I'd start with spark as mentioned above. Check the wires leading to the distributor to make sure they are not obviously damaged. Check the pickup coil (inside). Check the ignition coil by swapping it and checking symptoms. Ignition control modules (icms) die from time to time, but their symptoms tend to be different. Kepp it in mind though, they can do strange things!! Check plugs and wires of course. Then I would go fuel. It could be an intermittent injector, although that is rare. Fuel pressure is a much more likely culprit. Pull off the fuel filter and try to blow through it. It should flow easy. If not, replace it. Check the fuel pump flow by jumpering it on at the ALDL (Get a container obviously, observe safety precautions). If it seems ok, reconnect and get a fuel pressure guage on the rail to make sure the pressure is ok. You could check the fuel return line by blowing it out with compressed air. Buy a compresion tester and check at least the rear 3 cylinders to get an idea of where your engine is at. Test the fronts if tyou think it's necessary. I don't think you are dropping a valve but maybe you are. Lastly, get a scanner and check the sensors feeding the ecm. You never know. It's a process, but not too hard. Let us know your results. Chay ------------- 86 SE 3.4 |