purebliss

I have a 1991 Lexus LS400 with 41,000 miles on it and is taken care of very good. Now my problem is today I was driving it when all of sudden I had no power and my rpms started to drop. I then was able to drive the car home. I have checked the fan belt all fuses and oil and tranny fluid. I started it up again and it drove with no problem but then when it was sitting in my driveway ideling it started to shake and the rpms dropped and the car stalled. I have no clue what it might be. It starts with no problem but if you stare at the rpm guage you can start to see the rpm guage move slightly and then it becomes complety unstable and sometimes stall. I have no clue I was thinking maybe a fuel pump? Well any suggestions will be great. Thanks guys.

purebliss

Bump-

I really need your help!!!!!
Okay the dealer replaced the Fuel pump restior relay and some other relay. He said it was only giving the car 4 volts when it should have given it 8 volts. So thinking the car was fixed I drove it home 40 miles and shut it down with no problem. THen I go to restart it and it starts to act up again meaing the engine starts to sound like its going to stall out but then at the last second the rpm guage goes up and it gives it power not to stall but if I keep it running or try to give it gas it will stall. SO the problem was never fixed anyone with any idea of what this is? It only happens sometimes mostly after driving the car so it's hard for a mechanic to repeat the problem.

Here is a recap of what happens.

I start the car with no problem and drive it with no problem for awhile. But then out of know where I lose power and the car will not go and it will just stall out. The engine will actually shake! Then if I go to start it up right away it will run but it will shake and then stall out. If I go to drive it just has no power and stalls out. But if I let it sit for a few hours it drives like there is no problem at all? SO strange>? They have told me if it was an idol control sensor it would run rough all the time and they told me the throttle body is fine. So what can it be???? I have the car with A class Mechanic from my dealer which is an elite of lexus dealer. ANyone having any ideas? Isn't stragne if I let it sit for awhile there is no problem? I have no check engine lights or any error codes. Does this sound like an ECU issue and don't you think they would have firgured that out?

Anyones help would be great! thanks guys
Just a side note the car is a 91 but it only has 40,000 miles and is well taken care of and is driven about 10 miles a day on week days!

jpcdmd

checked all vacuum lines?

Something is changing from the heat as the engine warms from driving possibly and then malfunctioning.

I had an old Volvo with a similar problem, turned out to be bad fuel injector seals.