Ok so I have an 86 305 TPI Trans Am and about a month ago it started to intermittently not idle so when I first opened up the hood I saw that there was a leaky injector so I assumed that that was the problem (maybe the car wasnt getting enough fuel to idle properly) so I ripped it down to the fuel rail replaced all the injectors and got it all back together as it ran for about 2 days no problems and now its doing the exact same thing. So basically what its doing is it will not start when you crank it unless you give it gas and when it does start to keep it running I need to keep the accelerator down about half an inch to keep it idling; if I let off the pedal the car just dies. I tried disconnecting the MAF sensor to see if that was the problem but disconnecting it didnt have any effect so am I right to assume that it is not the MAF sensor? The only other thing that I can think of is its possibly the IAC valve.. any ideas from anyone would be greatly appreciated! Thanks in Advanced

 

Fuel pressure ok?

 

sounds like the iac is prob.dirty,take the throttle body off,remove iac cover and clean with carb cleaner and a brush.go to tech articles on home page and find tps and iac ,follow instructions.hope this fixes it ,later jimmy

 

If none of that works, you could try replacing the MAF burnoff relay. Mine had very similar problems until I replaced it with one that I had taken from a boneyard car long ago.

 

Inspect the Throttle Position Sensor too while your at it. Faulty TPS readings can contribute to engine hesitation, engine stalling, an erratic idle, spark knock, hard starting, and overall poor engine performance....

It's really hard to pinpoint the real culprit though, as without an engine code, we're all speculating because a lot of different ailments can cause similar symptoms. A faulty ignition module, for one, can cause similar problems as well....

-Gaspar

 

ok so i got error codes 34 and 35, checked the wiring at the MAF burnoff relay and its gone to hell so im going to replace that connector and ill give an update when i get a chance, thanks for all the suggestions so far, theyve been really helpful!

 

got the MAF burnoff relay connector rewired yet still no start, i cleared the codes, and then started the engine(holding the accelorator down so it would keep running) the ses light came on so i checked the codes and got a 33 and 34 im completly lost now..

 

code 33 is your map sensor,fix=check vacuum hoses from map sensor,check electrical connection at ecm,replace map sensor.code 34 is vacuum sensor circuit.fix=check the wiring leading to terminals 20,21 and 22 of the ecm, check the connections at the ecm,check the vacuum sensor wiring and connections( located in the engine compartment) check wiring on map sensor on the side of your plenum (pass.side) also be sure the hose isnt cracked and is hooked up.

 

thanks for all the help, it ended up being a dirty IAC, a REALLY dirty IAC at that haha, as for the codes I cleared them and as of yet they havnt come back, just a new 36 this time.. looking for a fix for that now haha

 

36 MAF sensor burn-off voltage was missing. Check MAF sensor burn-off relay and terminal "D" on MAF

There are two Maf relays one for burn off and one for power.

The power one has heavier contacts for more amperage. It can replace the burn off but not the other way around.

For the $11 az to $14 gm, it good to just replace both. I use the heavier one in both places for ease of trouble shooting.

This Voltage only happens at key off and for just hot sec.

Won't throw the code till the next start up. So... everytime ya gata unhook battery, to clear the code, then start stop start recheck for C E L

 

Thanks, I might have found my problem but I'm not 100% yet; after examining the schematics in the service manual I realized that I put the MAF burnoff relay connected to the fuel pump harness and the fuel pump relay into the MAF burnoff harness... you mentioned that there was a difference in the amparages between the MAF power and MAF burnoff, do you know if there is a difference between the MAF burnoff relay and the fuel pump relay? thanks

 

I think????.... power and fuel pump the same. try going to AZ online and check part numbers. try putting them back where they were and see what changes. also could buy one and swap it in one place at a time, seeing what changed.

relay contacts arc up after a time, still work just not the best. high power will be harder on the contacts. when moved to low power maybe not work at all.

after 30 years of cnc machine repair you learn these things.

 

AZ online? sorry im not sure what site your talking about.. haha I'm a little new at this whole self repair thing; I moved relays around and cleared the code, so far I havnt gotten it again but I'll probably know tommorow

 

AZ = auto zone

It is a parts store.

 

oh haha well it looks like just switching the relays around fixed my code 36 thanks for all the help from everyone!