92 Bonneville 3.8 has a problem. When cold, in the morning, it works OK. In 5 minutes or so when it starts to warm up the trouble starts.

I was suspecting the TCC solenoid and so I unplugged the plug the goes into the transmission housing and the problem is the same.

Before, it would hesitate and in awhile would stall. The other day the engine wasn't stalling and I put the car in drive. As I accelerated to start going, it appeared as if I was breaking at the same time and the car would move slow as if it was pulling a big load or as if the transmission was slipping, but the RPMs were only about 2000 or a little over.
It seems that when the engine gets warm the engine/transmission gets sluggish. As if the car starts to go but its in 3rd or 4th gear. Is this indicative of a bad TCC solenoid? This happens with or without the plug plugged into the transmission.

I am going to try another computer, maybe it is sending the wrong signals to the transmission. If it’* not the computer what could it be? A bad transmission? But then why do both the engine and the transmission work OK when cold?

Thank you

Well I am not much of a gearhead but based on all the posts i have read about 4t60 tranny problems it could just be it'* time but it could also be a simple fix or it could also be a $6 part in the tranny that requires 8 hours of labor.

Transmissions work with pressure, and when the fluid is cold it is thicker.

But has this problem just started slowly or sudden?

Are there any odd noises?

Is or has there been any "shuddering" or harder shifts?

Also how many miles are on the car or the trans?

Some problems may seem like a tranny but are really something else like a clogged cat converter or something else that is heat dependent.

Doesn't sound like a trans problem to me at all. Use the paperclip trick in Techinfo to check for codes.

If that doesn't show anything, do a full tuneup for starters. A trans won't make the engine stall or stumble. If the TC was slipping, your rpm'* would over-rev.

Also remove your TB for a thorogh cleaning. Remove all sensors, clean the IAC seperately, clean the MAF sensor filaments with rubbing alcohol and a Qtip GENTLY. Don't touch the TPS.

as an aside, if it is a transmission issue, you may be in 3rd or 4th gear. but the solenoid in question wouldn't be TCC.

i can't find the codes quickly for the 4t60, but here'* the symptoms of a dead 1-2 3-4 solenoid:
- the pcm commands max line pressure
- the pcm disables shift adapts
- the pcm inhibits downshifts to 2nd gear if the vehicle speed is greater than 48 km/h (30 mph)
- the pcm illuminates the malfunction indicator lamp

2-3 solenoid:
- the pcm commands max line pressure
- the pcm disables shift adapts
- the pcm commands third gear
- the pcm illuminates the malfunction indicator lamp
- the pcm inhibits the torque convertor clutch


That said, if it'* a tranny problem, it sounds more like the 2-3 solenoid. but, if your tranny is in pain, your PCM will know, and you should have a code. and a light. check those codes....

I disagree. The trans will not cause the car to stall.

Fix the stalling problem. If transmission symptoms show up, deal with it then. But for now, the stall is NOT related to the trans.

the only time i have ever seen a GM transaxle (late 80'*/early 90'*) cause a cars engine to stall, is after a steady cruise speed which activates the TCC (above 45 mph) and when comming to a stop the car will buck and then stall (like a manual trans without the clutch depressed) because the TCC doesn't release from lockup. and because it is usually a mechanical solenoid failure (i'd say 80%) the PCM will not trip a code

However this has only occurs (for me) on the 125/200 etc 3/4spd tranaxles in the smaller GM cars (our shop carries the solenoids in stock cause we seem to replace more than a few a year) I have not seen this problem on the 4t440/4t60 etc at all!
The easy fix for the TCC prob (if you dont mind less fuel mileage) in the 125 3/4spds is to unplug the blue 4 terminal plug on the trans case in front and live with the CEL (a few of our customers had us do this till they could afford the labor for the solenoid), If your trans doesnt have this blue 4 terminal plug on the front, upper portion of the case you more than likely do not have a TCC solenoid problem.

Have your vehicle road tested with a Snapon MT2500 or equiv scan tool connected to verify proper solenoid opperation and to verify whether you might be experiencing turbine shaft slippage (a difference between engine rpms and turbine shaft rpms). a 92 OBDI should have these PIDs (Parameter Identification) for you to see whats happening in real time.

Good luck with the diagnostics
regards James

I have good news (for myself ). The Bonneville is working fine. I took it to
an AAMCO shop and they said it was the transmission and it had to be rebuilt
or replaced, it was messedup and in the wrong gear, and they did drive it around
the block. Because it didn't make sent to me since it worked OK when cold, I went to another transmission shop, kind of a family shop, I didn't take the car because I didn't want to force it anymore. I just described what the car was doing and the guy told me to check the computer. So, I went to a junk yard and got a used one, $75.00, and replaced it. The car is working fine now. I drove it for about 45 minutes and no problem. I don't have much doubt that it is OK, I will see in the next few weeks.

I did put back the old computer and it does have a problem. Now, I think
this is important, in my experiments I discovered that if the battery in the
car is low, the problem is much severe. When I put a battery that I charged
during the night, the car did hesitate etc. but the transmission didn't feel
like dragging a heavy load.

Tony

Low electrical means low spark voltage. Your plugs are probably fouled. You need to check your alternator.