I have an 87 IROC w/ a 350 TPI and when the car is cold it starts and runs great. But when it gets up to operating temp. the car sometimes won't start????? I checked the engine trouble codes and at first it flashed 34 which is the MAF. So I replaced the MAF with a Bosch OE MAF and 34 stoped but now it is flashing 33 and 36. I don't know what the burn off relay (36) looks like or where it is? And I don't know what the hell the 33 engine code is trying to tell me. these manuals aren't helping. The only thing I can see wrong is the plastic circuit on the bottom of the MAF is warped and I can't tell if it is working properly. Someone please Help before I do the unthinkable.

 

I got no idea how to check it but here's a pic. This is from Vaders' T/A I hope he doesn't mind. It looks just like my '86 Iroc. Maybe this can be a starting point for ya.


[This message has been edited by John Boy (edited March 25, 2001).]

 

Code 33 means either you have an air leak between the MAF sensor and the throttle body OR the wires at the MAF burn off relay or MAF power relay (I forget now exactly which one)are touching or shorting each other (it's happening to me right now). Code 36 means trouble with the MAF burn off. Here is what you need to do. First check your intake ducting and make sure the hose is sitting "right and square" and there are no holes or cuts. After that's done pull the 2 relays (refer to the pic above or car manual) and go to the auto part and buy 2 new ones; they are like $10 each. Before you put them in, look at the wires going to these relays and make sure the contacts inside are clean (they probably have some nasty grease in them, this is fine), remove any rust or dirt. Look underneath, where the wires go into the relay and make sure they don't touch each other. Then put the new relays in; make sure they are tight.
I guaratee you this will fix the problem.
Rick

 

Also check the weatherpak connector at the MAF, the contacts could be corroded. If they are, just clean them with a jeweler's file and/or a q-tip with alcohol. Like what was mentioned before, make sure your MAF is seated squarely in the airbox ducting, there is a small notch in the MAF sensor that has to line up correctly with the ducting. Check THOROUGHLY for grounds/shorts in your MAF relay wiring with a voltmeter. If all that checks out, and you have NO vacuum leaks downstream of the MAF, check your TPS voltage to make sure it's .54vdc +/- .75v. That SHOULD do it. If not, and you have already replaced your relays, you might start looking at your ECM.

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Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, MSD 6AL, Aluminum Driveshaft, TB Coolant Bypass, Ported Plenum, Modified MAF, Syclone Fuel Pump, JET Airfoil

15.556 @ 86.65mph, Nov 10, 2000.... I know it sucks.. but it will get better!

http://www.geocities.com/transam85tpi/

Member - The Tidewater Trans Am Club, Norfolk VAhttp://www.geocities.com/ttacva/

 

Check your electrical connections. My car wouldn't start when warm or hot either for a while and I finally found the positive cable to be loose. (starter needs more power to turn over the engine when warm)

Steve

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89 GTA G92
305 TPI WC 5spd w/3.45
Accel Cap & 8mm Taylor's
Custom 4" Cold Air Induction
Jet Airfoil
K&N Airfilter
160 deg stat/fan switch TB Bypass - Steel Rad
Cat back 3" Exhaust w/Terminator Muff.
HiGh FlOw Dynomax Cat
Spohn LCA's - KYB GR-2's
Moroso Crank Bolt and roller pilot bearing.
Autometer Vac+Oil Temp

 

If you have a larger cam in your car the same thing will happen and can be fixed by setting your TPS back to betwen .35 and .40.

Good luck. Otherwise these guys have it covered.

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-86 IROC
Vortech Supercharged 406
-=ICON Motorsports=-
"Well, you're equipped to be a prostitute, but you're not one, are you?"