Lumina stalls/hesitates/lunges

[howboutthat]

Hello, I have an old '91 lumina 3.1 @190k that was running great until the other day I first noticed a slight miss or hesitation as I was accelerating from a stop sign. It drove decent but has progressively gotten worse.
Now it seems to start fine and run fine until it gets good and warmed up then it really dogs it when trying to accelerate (especially when accelerating from a slow speed and pulling a load or up an incline).
If I give it a lot of accelerator it really cuts out, if I keep holding it down it will lunge almost in a 1 second rhythm until I ease off the gas enough where it will eventually run out ok.

I changed the fuel filter and added injector cleaner. Within the last year I changed the O2 sensor and about 50,000 miles ago I replaced the control module and the plugs about that time as well.

Any help or suggestions would be appreciated.

[comptech_69]

I was going to say replace the fuel filter but you already said that you did. Might be a fuel pump, check your fuel pressure and go from there.

[howboutthat]

Thanks for the reply comptech_69, I will check the fuel pressure, the only thing is, it puzzles me about it only running bad after engine is really warm. Didn't seem like that would affect fuel pump pressure.

[comptech_69]

You know what I just thought of, I had this same problem on a customers 93 cutlass withe the 3.1L. After it warmed up and you tried to accelerate at all the car would sputter, buck, and even backfire or stall... It was the fuel injectors. With 190k it sounds like that might be your problem. Getting 6 new injectors is kinda pricey (around $360 for all 6!!), so search around and see if there is any local place by you that professionaly cleans them (I've never seen fuel injector cleaner that actually works yet).

[NeonKnight]

use this website to get reconditioned injectors.

www.injectors4u.com

[richtazz]

Try unplugging the TCC solenoid, as it may be stuck, not allowing the torque converter to unlock. This will cause the car to buck like a stick shift trying to accelerate from too low a speed in too high a gear, especially under load or going up a hill.

[comptech_69]

Originally Posted by richtazz

Try unplugging the TCC solenoid, as it may be stuck, not allowing the torque converter to unlock. This will cause the car to buck like a stick shift trying to accelerate from too low a speed in too high a gear, especially under load or going up a hill.

That wouldn't be the problem that hes describing though. I had that problem on my '91 with the TCC and its totally different.

[maxwedge]

I'd have a fuel press gage on this and look at what you have when the condition occurs, based on the description of the surging at throttle.

[rlflynt]

Originally Posted by maxwedge

I'd have a fuel press gage on this and look at what you have when the condition occurs, based on the description of the surging at throttle.

some other things that will cause your symptoms is a plugged cataliyic converter, bad plug wire/coil. My 95 lumina had the exact same problem and do mean exact. no trouble codes showed on an obd1 scan I was told to check the plug wires. I didn't think this was it seeing how I just put brand new plug wires on it with a tune up!!! checked all the sensors and they showed to be good. (thanks to a haynes manual) so i put the old wires back on and no more problem!!!!!! Make sure to check ALL sensors even if you don't get a code. I have found out that over 9 yrs most of the sensors cause problems that act alike. Hope this helps I know with GM's wonderful 3.1 fixing it seems like your chashing your own tail sometimes.

[corning_d3]

Change the plugs and wires, MAN!! Seriously though, plugs and wires are a must. If you decide to change them, go back to the OEM AC Delco's. Could be a faulty Throttle Position Sensor, too....Although i think that'd set a code.

[rlflynt]

Originally Posted by corning_d3

Change the plugs and wires, MAN!! Seriously though, plugs and wires are a must. If you decide to change them, go back to the OEM AC Delco's. Could be a faulty Throttle Position Sensor, too....Although i think that'd set a code.

I always run boush plug wires always had good luck with them. the new ones that were bad was a set of autolite. I went and got a set of boush and no problems. mind you they cost almost twice as much but I found when it comes to the time to hunt down problems sometimes more expensive means better quality parts. If he has a haynes manual it will tell him how to test tps sensor. all he will need is a volt/ohm meter (no more than $30 @ autoparts store) A must have to work on these beasts!!!

[howboutthat]

I did a diagnostic check and found 3 trouble codes, 23-(Intake air temp sensor high temp indicated), 44-(O2 sensor lean exhaust), and 45-(O2 sensor rich exhaust). I am also leaning towards cat converter rlflynt, since I just replaced O2 sensor a year ago

[corning_d3]

A faulty air intake temp sensor can cause a rich and lean condition, depending on whether its shorted or open. Have it inspected/replaced.

[rlflynt]

Originally Posted by corning_d3

A faulty air intake temp sensor can cause a rich and lean condition, depending on whether its shorted or open. Have it inspected/replaced.

I agree with Corning on this one test the air intake temp sensor and rule it out first. A cat runs about $90 (obd1) and more for (obd2) if the A.I.T. sensor is bad it will cause the O2 sensors to read wrong. Make sure to clear all of your codes after replacing and/or test sensors

[dafeeder]

Originally Posted by howboutthat

Hello, I have an old '91 lumina 3.1 @190k that was running great until the other day I first noticed a slight miss or hesitation as I was accelerating from a stop sign. It drove decent but has progressively gotten worse.
Now it seems to start fine and run fine until it gets good and warmed up then it really dogs it when trying to accelerate (especially when accelerating from a slow speed and pulling a load or up an incline).
If I give it a lot of accelerator it really cuts out, if I keep holding it down it will lunge almost in a 1 second rhythm until I ease off the gas enough where it will eventually run out ok.

I changed the fuel filter and added injector cleaner. Within the last year I changed the O2 sensor and about 50,000 miles ago I replaced the control module and the plugs about that time as well.

Any help or suggestions would be appreciated.

What was your problem in the end?