I have a 1989 Z24. It has the original 2.8L V6 and only has 24000 miles on it. I have been having a problem recently where my vehicle will stall out when I let off of the throttle as am breaking or turning around a corner. If I throw the car in neutral and give the engine a little gas, I am able prevent the car from stalling out. It is a sporadic issue and some days the car will run great. I took it to a mechanic last fall, but he was not able to reproduce the issue. Has anyone else ever experienced a similar issue? I would like to track down the cause of the issue and I am looking for some additional clues.

Thanks for the help,
Brendan

If the car is a automatic the problem is the TCC torque convertor clutch (switch or solenoid depending a parts listing).This screws into the transmission and is problem shot,due to old trans fluid and here is what to do.I would recommend replacing the part and draining and replacing the filter and the part.U can disconnect it,this will only affect the mpg of the car.Being I own a 4spd manual I do not know exactly where it is located on the transmission but ,it from what I recall has a two or three wire plug going to it,unplug it and if the problem stops that is ur problem.I realize even with low miles u would think the fluid is ok,but age does affect it even from just sitting and the short is the fluid gets hotter than normal and cooks the switch (burning it up) if u just replace the switch the fluid will cook the new part in short time.That is my recommendation based on ur symptoms.Ok Advance auto or auto zone may show a pic of the part just check their sites enter ur car info and go and it may be listed as a switch or solenoid in trans parts if u do not find it in there quick searches.

I had a similar problem with my 88 Z convertible. It would run great somedays and other times it would die when coming to a stop. It turned out to be the fuel pressure regulator was bad, once I changed it the car run a lot better and the stalling went away. If it was the tcc solenoid sticking, the car would start shuddering real bad as you came to a stop, just like a manual transmission car that you would try to stop without depressing the clutch.

Unplug the TCC solenoid first. If it stalls out again, try an idle relearn.


I hate snakes in the grass who just wait for the weak
and then pounce.

Had an extremely similar problem with a '88 celebrity with a 2.8L, and it ended up being the computer. Idle had a mind of it's own. Sometimes idled fine, sometimes was about to die, and sometimes idled high. Seems to be a semi common issue, as the computer I pulled from the junkyard was a remanufactured unit and the one in my car was also remanufactured. Celebrity only has 160,000 miles on it and the computer is behind the glove box so to me being on the third computer is excessive. FWIW I think the computer in a 89 cavalier is the same as the one in the celebrity.

Had a similar issue also. 2000 Cav Z24, 5sp, 115,000 miles. Car ran fine but would stall after short warmup - if in neutral and revved engine above 2K rpm and let off gas quickly. Speed would come down like normal but aroung idle the tach would drop to 500 then stutter and jump up around 1K then die. My son and I replaced crank sensor, no change. Cam sensor, no change but while pulling off plastics to get at sensor; noticed the vacuum hose between manifold and MAP sensor was very soft. As my son removed it the hose tore larger than the hidden hole on the hose. Replaced hose and WOW this car feels like NEW again! Thoght we were getting close to a clutch job but after the hose was replaced it shifted and took off like a new car again. Cost of Crank sensor - $45.00, Cam sensor $35.00.... Value of $1.35 hose? PRCELESS!!!! Hope this helps.

Those are all very sound theorys, but before you start just throwing parts at it, try and diagnosis it first, if you have a check engine light (which I dont think it does) try and see if you have history codes, if it is not on. If you do not have a light, look in your service manual there is a procedure that will allow you to pull codes with out a computer. It will make the brake light flash so many times and that amount is a number and that is your code. From there you can narrow down where you trouble is. Even if you are not currently experiencing the issues there should be a history code, you computer will always store them till you go in and erase them. This will give you a starting point to finding the problem.


Just remember CODES DO NOT DIAGNOSIS IT they just tell you where to look

I just reread the post and I did post b4.I would change out the fuel filter( sounds corny) but even though the car is low in mileage its been like on the car for yearsssss.I would spend five dollars,and prolly change the plugs, wires if it were me and then see if the low cost fixes the issue.Fuel filter is my guess after reviewing things and having a fresh look at the question.Typically the most simple parts start to fail that cause problems alot of the time but,not not always.

it could be also your fuel pump, if its getting weak it will cause a similar problem as your tcc.

Agreed u could do a psi check in minutes to verify that pump is going or not.And if you check it it should read 41-47 psi and if u disconnect the regulator vacumm hose the pressure should change 5 -10 psi.Just checking the pressure minus pulling the vacumm line should be adequate.Yeah pump failure symptoms car choking,loosing power briefly,hard starts cold or hot ,cutting out under a load etc.I would not rule the pump out but,would replace the filter first and see if any change then do a psi check on the pump.

Thanks for the advice. I replaced the fuel filter last week and there was no change in the performance of the vehicle. The car is not displaying any check engine codes so I do not have a lot solid clues. The problem has consistently decreased over the past few weeks. Since the symptoms have changed a bit, I thought I would update my post. It is really hard to get the car started now. I need give the car some gas when I turn the ignition. Most of the time, the car will die as soon as I let off of the gas. As long as I give the car some extra gas and keep the engine above 500 RPM, the car will continue running.

I was talking to a mechanic last week and he suggested that I check the IAC sensor. I ohmed the sensor out over the weekend and it seemed to be fine. The measurement on the A and B terminal had a reading over 50ohms. The measurement on the C and D terminal showed the same. I might try to run out this evening and get a pressure gauge to check the fuel pump. Thanks for any additional advice.

wow um OK well i need to speak to you guys my car dose have that heavy stop and stalls when i push on break is it the ttc or trans fluid ? it is acting like a manual transmission as if it wherent being pushed in pleas helppppp

Well being it is a automatic it probably is BOTH the tcc switch and fluid! Short version the fluid over time looses it properties to properly protect the trans from heat,shifting,etc.In turn what happens is the HEAT burns up the tcc and the real correction is to change your fluid,and filter THEN change out the tcc switch with a NEW unit.And noting the fluid never really wears out it is the additives in it that dissapate over time due to use and temp.You can disconnect the switch and only affect it may have is reduced mpg.But being the age of the car I would seriously change out the fluid and filter bc long term can put a hurting on the trans itself.Simple I hope this .

Did you try checking you TPS? Mine went bad and it would not rev pas 2500rpms. Also the was a time when my starter went bad and my battery at the same time. The start was so bad it was drawing power from the battery all the time. One I replaced my starter and battery never had a problem starting. I would stop somewhere for 10mins shut the car off and it would not start without a jump even though the guage read 12v. Then after I replaced the battery the car would take about 20 seconds of cranking to start so I went and bought a new start, got one for a 3400 as they are half the size and twice the power. Now the car starts in 1/2 a second. I would also check your grounds and battery terminals. Check the simple things.



On the inside my car looks like a fighter jet.