3princesse

Hi I don't know much about cars but I have spoken to many mechanics and anyone who knows anything about cars. Have not taken it to the Lexus mechanic as of yet. Here's whats going on...as you are driving the RPMs will rev up to 3000 to 4000 and the car will jerk. Sometimes it does this until you turn the car off and restart it. Recently it has started with a new thing. When the gas is applied the RPMs will rev and the car will not go past apx 20MPH or so. This has happened 2 times now. Before taking it to the mechanic does anyone have any ideas. I have read one post where it was a timing issue and another a trans...both are costly and I dont want to have to do both things right now. Its a 92 LS 400 with 113,000 miles. Previous owner took very good care of the car. Thanks!

cobalt91

Maybe the trans? Have got a CEL?

RA40

iTrader: (6)

Welcome to Club Lexus.

The FAQ is also applicable to the earlier years:
https://www.clublexus.com/forums/ls4...questions.html

My thoughts would be this:
Check for any engine codes. Is there a check engine light on the dash?

Other possibilities:
1. When was the last transmission fluid service? Check the color of the fluid. It should be bright red to burgundy. If it is darker or black
https://www.clublexus.com/forums/ls4...er-thread.html

2. Basic tune-up with spark plugs, caps, rotors and wires.

3. Check that the fuel injection is at proper pressure. Also relates to the fuel filter and or fuel pump if pressure is low. There may be blockage-clogged filter.

4. This has been a pretty big thread to consider as well:
https://www.clublexus.com/forums/ls4...capacitor.html

LScowboyLS

I would have the transmission filter changed by the Lexus dealership and T-IV fluid used - do NOT have the transmission flushed.

From your various symptoms though, failing ECU capacitors is the most likely issue. These capacitors have a factory defect, and even if they didn't, they are only designed to last around 12 years, and your car is 22 years old!

The good news is that these cars have perhaps the best transmissions ever made as far as durability and reliability, so if any place is telling you that you need expensive transmission work on this unit at 113,000 miles, then run like hell, that place is either wanting to scam you or doesn't know what they are talking about. - The transmission's in these cars are good for 250,000 miles at a minimum!

3princesse

as of yet there has not been a check engine light although it has been checked for codes at least 3 times to no avail. All plugs are newer (last 6 months) and I believe they did change the fuel filter also but I dont know if the pressure was checked...I would have to look at the paperwork.

LScowboyLS

no check engine light or codes is also yet another symptom typical of failing ECU capacitors, it's not a 100% lock, but you have a stack of the right symptoms, so that's my vote!

RA40

iTrader: (6)

What color is the transmission fluid?

3princesse

Im not sure what color it is. My husband has the car right now so I wont really be able to check until tomorrow when it's light out. So this may sound really stupid but how do I check it? Is it like checking the oil? I know some basics but that's about it. My husband knows about as much as me as he is a salesmen and the only technical type training he ever received was about guns and heavy artillery in the Navy...LOL He's not much of a Mr. Fix it . I was lucky to have a father who taught me how to fix stuff but I never got interested in cars~ I can build you a beautiful potting bench for your garden though...till tomorrow...and thanks all!

LScowboyLS

yes, just check it like the oil, except that car needs to be running, in park, and you need to have shifted through the gears prior to checking it, and the car needs to be on very level ground and hot from having been previously just driven.

get a white coffee filter wipe the dipstick on to accurately assess the color