ls400x

Hello,

I have got a 98 with 104k miles, meticulously maintained by me

I have been having an issue i cannot resolve. When driving say 35-40 mph i push the gas pedal 50% about half way where the car will downshift say into 3rd, which it does, however, it sort of bogs for a second as if there is no fuel delivery. The strange thing is it always happens when i press the gas 50% and when the speed is between 20-40 mph.

Also if i manually go through all the gears there are no issues at all.

I also from time to time reset the battery and do a couple power runs so that the ecu memorizes the gear shifts. However no matter how many time i reset battery the intermittent bogging does not go away.

I also pressure wash my car at the self car wash centers and usually pressure wash the engine, perhaps the water is messing with the electronics.

If anyone has experienced this before, please help me out

Thank You

LScowboyLS

I think the risk of this greatly outweighs any reward

if you want to clean your engine, I would use a rag and a mild solvent (such as Marvel Mystery Oil)


as far as the bogging problem, you need to determine whether it is a shift control issue or a general bogging at a certain rpm, in order to solve it

all of the shift and other transmission control is handled by the ECU, the only electronics inside the transmission is really just the 6 or 8 various solenoids

have you scanned this car for codes? (regardless of whether the check engine light is on)

RA40

iTrader: (6)

Welcome to Club Lexus.

Washing the engine is not a good practice. As LScowboyLS mentioned, using a rag with your favorite cleaner is the better approach. Water pushed into the wiring harness and other electrical connectors-contacts is a sure way to have problems and more so as these cars age.

The other is the ECU and in these past few months we've had many threads discussing the various symptoms.

Scan for any codes and let us know.

ls400x

Thanks

I won't pressure wash the engine anymore. I will scan for codes and post back.

Also this is not an rpm mechanical engine issue. It is probably and ecu/ control module problem.

Thanks