Help? I have replaced:MAF,Maf relay, burnoff relay, maf connector, set the TPS, replaced ECM and gone wire by wire through the schematic for continuity and still my 87GTA-350 runs like crap. Some days it runs beautiful. Other days the SES light comes on and off but still runs decent. Just yesterday the car would not run after it warmed up. I had to restart and go 100 ft. then restart again all the way home. Guess what? No codes even when SES light comes on. Anyone have any suggestions? I'm ready to give in and take it to the dealer. Kevin Irving has been a big help but I haven't talked with him in a month. This has been going on since mid-May.

 

What makes you suspect the MAF? Done a good tuneup on it lately? O2 sensor fresh? If all is good, then might be time to plug into it with a scanner and see what the ECM see's.

 

Yes, I have done all that. I have my own scanner and the only code it has ever given is 33 or 12. Sorry but maybe I didn't give enough info on my problem. I have tried everything I think and am hoping someone else has had the same problem!!! This is my son's car and has turned into a nightmare. I am afraid for him to drive it. It is embarrassing sometimes and I have had T/A's since I was 15, but never a problem like this.

 

Your problem might not be in the electronic components but in the fuel system itself. Maybe you got water in the fuel, plugged filter or even the injectors.
Also a MAF code can be set off by a plugged catalytic converter.

 

Will a plugged fuel filter or injector cause the SES light to come on intermittently? I have a new flowmaster exhaust on the car from the engine back. The converter is new also.

 

[quote]<font face="Verdana, Arial" size="2">Originally posted by kdvol:
[b] My o2 sensor hasn't been replaced for 30,000 miles but I am getting no codes for it. I have spent over a grand replacing parts on this car because people suggested this is the problem. Is there a way to check the o2 sensor before replacing it?

 

I had the simliar problem.I went to a mechanic and told me it was the Air Control Valve, maybe the MAP sensor and possibly the Engine coolent sensor. After I changed those sensors the bird ran like new.

 

Distributor Pickup Coil....?

 

I have spent over a grand replacing parts on this car because people suggested this is the problem. Is there a way to check the o2 sensor before replacing it?[/B][/QUOTE]

My suggestion is to quit tossing parts at it and either:

Get a manual (Chiltons/Haynes are okay to start) or Helms if you want all the correct year specific info. DMM, FP gauge, vacuum guage and MightyVac. Begin in the trouble shooting session and go through each thing one by one that you feel pertains to your problem.

You can't always rely on what the scantool tells you, the sensors could be reporting false info. What does make the scantool an invaluable tool, is the ability to look at several things at once, and see what's not right...i/e your O2 sensor may be reporting good info for the ECM to process, but maybe the mv's are at the top of the scale, indicating too rich...just an example.

If you don't have the time, then next best bet would be to the dealer.

 

Code 33 is a high voltage on the green wire to the MAF...when the ecm sees this and sets the code,the car will begin to run like crap.
Code 33 is also a unrealstic air flow into the intake sytem.
One cause of that is a larger throttle body, like a 52MM. or a misadjusted minimum air speed screw and TPS.

I was shooting a code 33 when I installed a larger throttle body...found out the minimum air speed screw was not adjusted properly at first...even though TPS was set to .54 volts.

This can still happen with stock TB's that have been adjusted wrong.I would check to see if the TB screw has been screwed out too far.

If so, back it off until it doesnt touch anymore, and then turn it back til it just pushes on the throttle stop.
If youre not sure, do this anyway and follow the manual's adjustment to set the minimum air speed screw idle speed then adjust the TPS to the correct voltage.
This might hep IF this is whats wrong.

Ive seen people throw alot of parts at their cars and the entire time the damn thing was not adjusted properly.

Doesnt hurt to perform this check.

A GM shop manual is best..I urge you to get one..it can help you troubleshoot step by step to locate the problem for anything on the car.



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1986 Vette Coupe,auto, 357 L98 w/alum. heads,40 over,crane cam,3.73 Gears,The usual Mods..
Had an 86 Bird before..want to get another F car again!