air care issues

Hey Ryan, this is my Air Care sheet, from my 88GT.  Note my idle Hydrocarbons were only 67ppm.  

     I say drop your fuel pressure, make sure you plugs are at least .050 gap. (Stock is .045, the slightly larger gap gives you a bit more spark)  I am assuming you have MSD Coil.   A good ignition system is crucial to low HC's.  High HC's are due to extra fuel being spat out your exhaust.  It also means you are wasting a lot gas and getting really bad mileage.   My 88GT driving it 100% in town, with my foot to the floor all the time I still get 250kms out of tank.  On the highway I get 500kms from a tank driving at an average 120kph.  

Your motor should have higher compression than mine which should help you out a bit.  

Maybe you should post a list of what parts and brands of parts you have recently changed in the car.  I know you and Patric did a tune up at the club tech session, but I can't remember what parts were replaced.  

I'm not an expert by any stretch of the imagination, but a damaged or dirty O2 sensor will also cause the engine to put in more gas than it needs. Cherry on top is that they're cheap to replace.

Well now that you are running at a low enough fuel pressure, 28psi, the only thing I can think is better spark.  Oh and a quick note, the EGR will actually increase your hydrocarbons.  When the EGR activates it adds spent exhaust gases into the intake, which reduces the available Oxygen hence reducing the amount of fuel being burnt.  So you end up with extra unburnt fuel and a higher hydrocarbon reading. 

But back tracking a bit, that would only be even remotely important during the drive test.  At idle the EGR does not come on.

The test I did at the meeting was to physically grab the EGR diaphragm and push it up, when I did the EGR pod opened releasing exhaust into the intake and causing the motor to die, when I released it the car went back to fine, so that pretty much confirms that it is working correctly in the mechanical sense.  However it says nothing about the electronic portion of it.  If you have not bought an EGR unit yet, I have a box of them you can come and grab one.  I usually remove the EGR system on all the Fiero's I work on.    Once a year when they need Air Care, I toss in a bottle of Methylhydrate to reduce the nox and call it good.   One note, the Methylhydrate can increase Hydrocarbon emissions at idle.  If your NOX are fine, I would just leave it out of the mix.

The list of things that I would do, (if you have already done them you can ignore)

New NGK Rapid Fire plugs, gapped at .050

MSD Blaster II Coil and Good Wires

Genuine Delco O2 Sensor

Bump timing to 12 degrees.

Remove the Air Filter for the test.

Check your Intake Air Temp sender, if it is bad, it will cause the car to run rich.

Oh when you go to do the test, a trick that works to reduce high hydrocarbons especially in a worn engine, is to remove the Breather tube going from the rear valve cover to the Intake Pipe before the TB.  In an extreme case you can even block the PCV valve. Every little bit of bad air you can keep from going into the engine will help.

Sorry it was through various phone and pm conversations.

Well when you get the plugs out take a few really good high res shots of the plugs and post them here.  Specifically the ceramic tip around the electrode.  Black means too much fuel or not enough spark, Bleach white means too little fuel, tan colour is correct.  Pay special note to tell if all the plugs are the same or not.  If you have one that is really radically different than the others, the first thing you should do is a compression tester on that cylinder and the adjacent cylinders to make sure you have even compression and not one odd cylinder.  If compression is fine and you have one bad plug, check the plug wire to make sure it is not bad.  If the odd plug is bleach white, it means that, that cylinder is running lean, probably due to a fouled injector.  Because you have the Mustang injectors, I think a new/reman one is only about 30 bucks from Lordco.  (Fiero injectors at last check were about $280 Each.) I was lucky enough once that I had gone out of my way to help a guy clean out his Fiero parts and he handed me a nice brown box with 6 plastic baggies in it, and a receipt for over $2000 it was a set of BRAND NEW injectors he had bought for a Fiero that he no longer owned and had never installed.   I just about fell over when I confirmed the part number and prices at Eagle Ridge Pontiac.  (we have a club member that works the parts counter there)

You also have the option of getting all of them flow tested and sonic cleaned in Langley for about $25 each.  In some cases I prefer to get them cleaned, tested and rebuilt as then I know they are perfect and there are no issues.  Some new ones have had issues right off the bat. 

today I installed the new IAT sensor, but did not replace the O2 sensor as it looks "as new". though I did note that it is larger than the factory ones, could it be a wide band o2 sensor?

I pulled all of the spark plugs and they all appeared to be a light beige in color, similar color through all of them. the gaps were set at approx .050, one was a bit off but now they are all dead on.  I have the pics of the spark plugs but they are too big to upload onto the forum, I can email them to anyone who wants to see them though. 

I havent gotten a custom prom burned yet, I'm trying to fix this on a bit of a budget right now as i'm not working at the moment and the datalogger is a bit expensive.  will deffinitly get one done, but cant afford that much on a datalogger right now, need to find another job first

http://www.zeitronix.com/Products/zt2/zt2.htm

though I remember someone mentioned an alternative that wasnt as expensive, unfortunatly I dont remember what it was or who suggested it

havent done a leakdown test on the injectors yet, will search pennocks now to figure out how they are done, lol

88FormulaFiero wrote: ...did not replace the O2 sensor as it looks "as new". though I did note that it is larger than the factory ones, could it be a wide band o2 sensor?

That’s doubtful as the wide band sensors are pretty expensive and not commonly used. If it just has one wire connected to it, I believe it's a narrow band O2 sensor (but I'm not absolutely sure on this).

This is what the Delco unit I recently installed looks like...

It looks considerably larger than other O2 sensors (which may or may not be Delco units) pictured below from other Fieros of mine.

 

I hope it’s an AC Delco O2 sensor you have, as I’ve read plenty of comments at PFF about how terrible the Bosch units work on the 2.8 in our Fieros.

88FormulaFiero wrote: I havent gotten a custom prom burned yet, I'm trying to fix this on a bit of a budget right now

With your non-stock engine, you may need a custom PROM in order to have the engine running properly enough to pass AirCare.

88FormulaFiero wrote: ...and the datalogger is a bit expensive... cant afford that much on a datalogger right now http://www.zeitronix.com/Products/zt2/zt2.htm though I remember someone mentioned an alternative that wasnt as expensive, unfortunatly I don’t remember what it was or who suggested it

Why are you thinking of buying a $279 datalogger when you can use an old laptop with a $27 cable running WinALDL (which is a free download on the ‘net)?

88FormulaFiero wrote: ...havent done a leakdown test on the injectors yet, will search pennocks now to figure out how they are done, lol

If your injectors are leaking you possibly won't be able to pass AirCare.

 

88FormulaFiero wrote: the thing that has me stumped is that the car, with this non-stock engine passed air-care fine 1.25 years ago with the same chip, and now passes everything but one reading which is waaay off. ...does the test I did mean leaky injectors?

Your AirCare readings indicate that raw fuel is pouring into your exhaust system while idling. I’m only going by what I’ve read at PFF myself, but yes, it seems that possibly your injectors are leaking. I don’t know enough about the procedure to suggest what else might possibly explain your fuel pressure dropping the way it does during the leakdown test (although I see that this is covered in your links).

Those threads you linked to are pretty good. The PFF member by the name of Dodgerunner in one of the threads is the fella who made the ALDL cable I bought for use with WinALDL. Listen to what he states as he's a knowledgeable guy. 

I need to run the leakdown test myself, as although I passed AirCare, my mileage is terrible and I suspect my engine is running a tad rich.

88FormulaFiero wrote: When I talked to Dr Fiero about getting a chip burned and told him what the modifications to the engine were he pointed me to that data logger to get the info he needed about the engine.

Perhaps you should ask John specifically if WinALDL would do the trick. It’s kind of a shame to have to spend almost $300 on a device to gather data to get one PROM burned for your car.

Ryan, how about posting the VIN for your Fiero so that I (and anyone else who wishes to be helpful) can have a look at your car's AirCare test result history.

 

Ryan you don't need the Data Logger, just ask John to burn a copy of my old 2.9 chip.  Its darn near the same engine as you and fuel maps were set for the 19# injectors as well as timing curve was tweaked to give you a bit more timing at the low rpms when the big cam was killing low rpm compression then as the motor revs up and compression is built there was a 3 degree retard above 3500 rpms to keep it from detonating.

88FormulaFiero wrote: wow, didnt even know you could pull up a history like that

Yeah, it's kind of neat, isn't it?