90ls400lex

Hello all! I need help!!!!!!!!!!!!!!!!!!!!!!!!
i have been reading through the forums and it sounds like I could rebuild the entire car with all the different suggestions.

Here is what I have. I am the second owner. 1990 ls400 with 140k. The first owner took great care of the car.
The only thing i need to do is replace the leaking power steering pump.. i'll get to that after i can figure out the hesitation issue.

When I would accelerating, the car would hesitate. No stored codes. Here is what I have done so far. I replaced the IAC value with a used one. Same symptoms. I also removed the throttle body and cleaned it completely out. Same symptoms. (the car idles perfectly fine) . I left it running for 30 minutes with no issues.

Here is what I noticed, it seems to only happen when the weather is hot or maybe the car is running in hot weather? I drove it to work and back on serveral occasions and the ambient temperature is around 60 degress.

I bought this car for my daughter's 16th birthday, and now I'm being hounded to fix the car!! I don't want to dump alot of money into it... I'm at a loss!!

johnnyg66

I would say dirty injectors and possible worn plugs and wires. Of course you might have a ecu issue too.

xhifer

Transmission maybe? Check ECU. Read the ECU thread.

deanshark

60* is hot? 60 would be perfect.
You're a good parent, buying your daughter a Lexus at 16, She's a lucky girl. The Ls400 is one of the most reliable cars.
But....it can get very expensive chasing down a problem. I would suggest changing the Engine Coolant Temp (ECT) sensor. It's one of the cheaper parts and makes a big difference on how the car performs. (Most important sensor your car has) I'm sure with 140K it needs to be changed.