djtgreen

Hello Family,
My 90 ls400 idles smooth until it warms up and begin to stall out every 5-6 secs. I changed the spark plugs, fuel pump relay resistor, fuel pump relay, maf sensor, and coils. Car continues to do the same thing. Fuel pump seems to be good since it runs smooth for 30 minutes till warm up. Im checking the open circuit relay when i get home, anyone have any other ideas. i reset the ecm already. Im stuck after the relay check tonite.
Thanks in advance for your assistance.

RA40

iTrader: (6)

Welcome to Club Lexus.

On the first gen one of the high list checks when they aren't running well is this thread:
https://www.clublexus.com/forums/ls-...capacitor.html

Other regular maintenance:
https://www.clublexus.com/forums/ls-...ange-pics.html

Some additional reading:
https://www.clublexus.com/forums/ls-...ing-power.html

dicer

Temperature related, could be ect, O2 sensors, I would be checking the components not just replacing them unless you have a good supply of parts. Well you may have some when your done. And was the LS4700 a special option?

djtgreen

Thank you, just got the Capacitors replaced, will put the Ecu back in tonite after work.

djtgreen

no special option just standard.

sha4000

iTrader: (1)

He was joking since you called it an LS4700 instead of LS400.

dicer

Another thing to check is crank position sensor.

djtgreen

Ok i got the Ecu back in with the new Capacitors, engine runs for 1hr:40mins now before the replacement capacitors it would stall out at 30 mins. Now its stalling at at the time mentioned above. Fuel relay is clicking as the car surges up and down. Im checking crankshaft sensor next, any ideas after this check would be appreciated.

jscoda

did you find out anything?

dicer

Running long is not likely the cps, fuel relay clicking could be it, or the resistor, especially if its time related like that as the resistor maybe heating up and changing value a lot, and all depending on the ambient temp there. Be happy it makes it past the 10 to 15 minute crap out barrier that mine and others have run into.

fixmiester

Didn't see where you replaced the fuel filter; should have been done first, before throwing money at everything.