idles ruff & hesitates at low speeds

[SpinnerCee]

I would not replace the MAP sensor -- I was illustrating that an exhaust restriction could cause the issue you describe.

Since you had the cat replaced already and it did improve things, I guess that was just part of the issue.

I'm kinda stumped -- maybe cleaning or replacing the injectors? I don't think the tranny is the culprit unless it is the lockup system (50mph is around the lockup point) -- I think the tranny is just "responding" to an engine power curve issue. However, it is better if the converter never locks up at all than if it stays locked up too long or locks up early.

[cjexotic]

so how do I prevent the converter from locking up?
How hard is it to get to the injectors to clean?
Is the converter locking what causes the vibration like its going over a rumble strip at certain speeds? thanks cj

[richtazz]

If the vibration/hesitation happens as you lightly roll on the throttle at 45-60mph, or as you come to a stop, and/or slams into passing gear as you described earlier, it is a TCC solenoid issue causing your problems.

[cjexotic]

where is the tcc solenoid and how hard is it to change? Any tricks?
thanks so much for your help.

[richtazz]

see post 6 in this thread for it's location and function. As far as replacing it, the side cover has to come off the transmission, and this can require that the transmission be dropped down so the side cover will clear the sub-frame. The part isn't expensive, but it's not a normal DIY job due to the difficulty of dropping the cradle.

[cjexotic]

Hi all,

Well i unplugged the lock-in lock-out for the torque converter off the bell housing, since I could not get anyone to change the TCC solenoid. All told me too many miles on car to pay to have it replaced.
So I was backed in a corner so I unplugged it. Ok it runs 98% better. Vibration is gone, hesitation is gone, shifting only is good (first drags a bit but can live with that), has power on hills and I EVEN HAVE MY OVERDRIVE BACK. Gas mileage has improve a great deal.

Well my problem is that when you first start it up there is a heavey gas fume. Unburnt fuel. After driving it its ok. Until you start it up again. I would like to solve this problem as I know it would help fuel consumption. Any ideas where I go now if anywhere. This care has 254,490 miles on it. I just want it to get me through the winter as I am making a motorcycle payment and can not do a car payment and fuel (heating) bill also. I will be riding my bike when i can but when the snow comes it just the lumina and me then. Thanks for any help. Cj

[richtazz]

pull the vacuum line running to the fuel pressure regulator and look for gas in it. If there is any, the diaphram is ruptured and that is the cause of your gas smell.

[dirtfarmer678]

My 90 Lumina shakes as well. I thought it was the cv joints but perhaps its the tcc. What are the consequenses of running the car with the tcc unplugged?

[richtazz]

I know of many people that have run for 1,000's of miles with no ill effects. Your highway mileage will suffer a bit (over what it was when all worked fine), and the trans may run a little warmer due to the torque converter slipping.