eagle_eyes

iTrader: (3)

this is a '91 firebird with a 3.1/auto. last week, it died on me driving down the road while accelerating. i pulled over, turned the key off, and turned it back on and it ran fine. i played with it at the house and found it running rich. i found a vacuum line going to the FPR broken and fixed that today.

I took it for a drive and it seems to run fine, except for when it's floored and shifting from 2nd to 3rd. at that point only, it cuts out. the motor is still turning, but about 2000 RPM and as I slowed down, the RPM's came down too...until i stopped...then it completely died. put it in neutral and it started and drove fine. i did this a few times. everytime it would die going from 2nd to 3rd at around 70 MPH. i can drive it normally, and it will cycle the gears correctly...1, 2, 3, 4, lockup.

fuel pressure is constant. i put a gauge on it to check while doing this. it does seem to run a little rich in higher RPM's, but when it cuts out, if i put it in neutral, it still wont rev up any until i stop it and turn it back on.

fasteddi

iTrader: (2)

Look twards the ignition system. Bad plugs, bad wires, arcing, corroded cap and rotor, or even a ICM.

eagle_eyes

iTrader: (3)

sorry, forgot to add that part...
i initially thought it was the ignition system before i found the broken vacuum. i changed the cap and rotor, plugs and wires were changed a few months ago. i pulled the plugs and cleaned them up after it was running rich. they don't look bad at all...not to the point of stalling a vehicle.

i also changed the oxygen sensor, and the coolant temp sensor. i tried driving it just a minute ago, and if i tap on the throttle a few times pretty quick, it will die.

eagle_eyes

iTrader: (3)

it does the same as this one...

https://www.thirdgen.org/forums/post...49-post33.html


this is the full thread.

https://www.thirdgen.org/forums/v6/6...ird-3-1-a.html

fasteddi

iTrader: (2)

You sure your fuel pressure is up to par? Then ohm out those injectors and see how good or bad they are.

eagle_eyes

iTrader: (3)

fuel pressure is perfect. just under 40 lbs at idle, and up to about 45 when accelerating.

i checked the timing, which was off. after adjusting it, it no longer dies except when first starting it, and when quickly wiggling the throttle open and closed. the idle sits around 500 for a second, then jumps up to 2,000, and slowly comes down to just under 1,000. sometimes, it will die before jumping up to 2,000.

i going to inspect and probably replace the idle air control valve today and see if that helps any. then i'll check the injectors.

fasteddi

iTrader: (2)

Make sure you disconnect the battery for a minuet once its warm and then put it back on and let it idle for 5 solid minuets. You must reset that ecm when you add on new parts or itll stay in failsafe mode.

Google Idle relean V6 thirdgen. And youll find the whole process.

Any injectors under 12 ohms at room temp... toss them in the trash.

eagle_eyes

iTrader: (3)

I cleaned the iac and it helped the idle a lot. I tried driving it this morning, but I didn't disconnect the batt first. It drove to the end of the block, then I turned and made it to about 20 and it sputtered and died. It always restarts without a problem, so I got it home. I'll ohm the injectors this afternoon and see what that looks like. I'm going to take the control module in to get tested too, since I never did that after it was running better. Thanks for your help and info.

fasteddi

iTrader: (2)

if it is indeed the injectors I recommed not buying direct oem replacements. Search out southbay injectors on here as they are some good ppl to buy from plus you get a TGO discount.

NCC-2569

iTrader: (1)

What happens when you floor the gas pedal? Does the engine die?

eagle_eyes

iTrader: (3)

i haven't tried flooring it since the recent problems. i'm not going to have time to work on it today, but i did finally get an SES light...

i moved it into my driveway, and in park, i can rev it up, but in drive with my foot on the brake...when i tapped the throttle a few times, it stumbled but didn't die. it was barely running and sputtered for about 10 seconds, then came back up in RPM. i got a code 33, 34, and 42 all at once. i haven't even looked to see what those are yet. i've got some friends in town tonight and need to go see them...so i'll look into this tomorrow.

NCC-2569

iTrader: (1)

Could be the ignition module or something else on the distributor, like the pickup coil.
If you can get your hands on a timing light, connect it with the cable of cylinder 1 and look for drop-outs in the light rhythm.
Had kind of the same symptoms once (but my injectors were also mostly dead), didn't get a code 42, though.
You can diagnose the ignition coil quite easily using a multimeter and a proper guide.
Diagnosing the pickup coil is more difficult and the ignition module itself cannot really be diagnosed.
I would suggest getting a remanufactured distributor, swapping it, adjusting the timing and maybe also swap the ignition coil... if the light pattern is indeed interrupted intermittently.

eagle_eyes

iTrader: (3)

I believe I got it fixed. Changed the pick up coil and module, then the plugs and wires. Runs good, but still a tad rough at idle... Which it's always been that way. No telling what the P.O. put it through.

Thanks for all the input and help. My other firebird died on me once last week to. The fuel pump quit, and all it ended up being was a loose battery cable. Everything else worked...starter, headlights, radio.... Just not the fuel pump. That one was a head scratcher.

NCC-2569

iTrader: (1)

Glad to hear this. Thanks for posting your solution