i have a 1990 Lexus LS400. prior to me cleaning the throttle body, the engine was running fine. i finally clean it with throttle body/fuel injection cleaner and when i turn the engine on it runs fine. i can put it in Drive, Reverse, Neutral and it wont die out if my foot isnt on the accelerator. however, when i tap the gas it will hesitate and then the rpms will drop and soon the engine will die out. what could the problem be? any information would be much appreciated. this sux should've just left the throttle body dirty lol



edit: also i tried to let the car run for 15 minutes. same result when i tap the accelerator. i sprayed the throttle body cleaner while the engine was off cuz thats what the can said. i cleaned it before, but it didnt have this problem.

 

Did u remember to plug back the maf plug?

 

yes i did....i even tried to check for vacuum hose leaks...i couldnt find any.

 

its 7 a.m. in tha morning and i tried to start the car. it wont even hesitate to die out. the rpms just drop and then dies. whats tha cause? am i tha only one that has experienced this?

 

How did u clean your TB? Did you take it out or you clean as it? When u clean the TB as it, dirt can go into the intake and mess up your valves and so on.

I would double check your wirings like MAF, TPS (2), Vacuum hoses, ISC (idle Speed Control)

 

i cleaned it as is.


i reconnected the plug


are you talkin about these hoses when you say "vacuum hoses"???


i actually sprayed into the black cylindrical piece(located far right, middle of picture) i didnt take that part off at the right. i dont know if that was the right decision, but i did it in the past and the car ran fine.


where would the idle speed control be located? the lexus is supposed to run at around 2000rpm's when the engine is first started. the rpm's didnt even do that. yesterday i noticed when i let the engine run for 15 minutes normally it would drop from ~1,000rpms to ~600rpms, but it didnt do that. i hope i didnt do any major damage to the engine. this sux

 

maybe i sprayed into the wires connected to the black piece? would that affect anything? i wiped inside the black piece with a dry cloth before i started the engine.

 

This topic might be related to your question ISC

 

problem solved

how much did i spend ? $0.00


this morning i was ready to call a tow truck and bring it to a shop. well i decided to give the Lexus another try before having to spend for a tow truck, labor costs, and parts. so i turned it on and was surprised to see the lexus gave me a few seconds before it died out. i start it up again and mash on the accelerator. the rpm's jumped to 6,000 rpms. i know its not healthy on the engine, but it was nice to see the rpms going up and not down towards 0 when i press the gas. so i stay on it until the temperature guage moves up a little. took it for a test drive around the block. the check engine light is gone and the trac control doesnt appear. im so content right now. thanks for your help lextreme.


i bought this car 6 years ago. SO UP UNTIL NOW I HAVE HAD NO MAJOR PROBLEMS WITH THE 1990 LS 400 with 265,000 miles on it.*knocks on wood 3 times* IM SO HAPPY WITH IT.

 

Sounds like you have some moister in your sensors.... either maf or tps.