pumpmikey

long story.....94 ls400 would not run......found both rotors fried and broken..left bank coil firing constantly.EVEN when engine not running...sent out ECM found ignition drivers fried..repaired and tested....runs great now but running way rich and will foul plugs 20 miles.....no codes in memory

pumpmikey

ls 400 sorry for tittle error

Ali SC3

iTrader: (10)

changed title to LS400 and moved to LS400 section.

change the plugs, hoping you already changed the rotors and caps.
sometimes they can't rebuild those things well. maybe try a good used ecu.
also could be a weak o2 sensor or a bad coolant temp sensor. on a 94 it hardly ever trips any codes.

timmy0tool

iTrader: (7)

who repaired your ECU? most shops are not in the know about what capacitors to replace.

happy reading!
https://www.clublexus.com/forums/ls4...capacitor.html

Kram

Check you cold start injector it my be fried in the on postion and this will not show on any code and would have been on when all the damage to your sytem happened,if the damage happened at cold startup.

pumpmikey

thanks for changin title for me.....circuitboard medics repaired it....have had good work from them in past...they cured ignition driver issue....and repaired injector drivers 2 yrs ago...said inj tested good...will check c,s, injector....THANKS

pumpmikey

94 ls400 does not have cold start injector....and I alreaady tested and replaced temp sensor slightly out of specs......Car runs great other than the plume of black smoke

sha4000

iTrader: (1)

You might have to pay to hook it up to a diagnostic machine that shows how the plugs are firing. Not the one to pull codes. It's the fuel is not being burned and some gas is being dumped into the cats. You need to find the root cause and take care of it before your cats are damaged.

pumpmikey

all plugs firing evenly....and all plugs are evenly soot covered after 5 minutes of Idling

pumpmikey

thanks for info...I had read that thread already.....may send out ECM to have them recheck

pumpmikey

thanks for info....caps for injection were replaced 2 yrs ago and doing fine...jus had ignition portion replaced and they said they tested Inj. portion of ECM...is there any test I can perform to confirm Cap problem??

pumpmikey

NEW SYMPTOM found!!! when trying to pull codes with jumper wire rather than scan tool......MIL and o/d off light flash..... anybody seen that????

pumpmikey

anybody out there with suggestions????

cobalt91

Is there a pattern to the flashing?

pumpmikey

no pattern...jus a steady quick flash