After I clean the throttle body and MAF on my 92 LS400, the RPM start a little higher then 1000 and idle roughly. After 30 second, RPM start decrease (I can feel the car is shaking) then engine die. start it again and it die within 10 secounds. I wait for two hours and try again same thing happen (RPM start a little higher then 1000 and idle roughly. After 30 second, RPM start decrease then engine die.)

I unplug the MAF sensor nothing change.

I use CRC mass air flow sensor cleaner and CRC Throttle body & air-intake cleaner


Any one know why?

Could be any number of reasons from the maf to injectors to ecu to coils etc, you will have to get the car checked by someone with test equiptment, expensive if you go to the dealers, don't know where "ca" is under your location so can't advise who to see...

Good luck

Pete

Assuming you didnt have the problem before cleaning?

In which case - check for debris in throttle body and make sure the butterfly valve isnt stuck.....I cleaned mine not so long ago and a tiny (and I mean tiny) thread of material from the cloth I used had got trapped between the valve and the body - Car ran like a complete pig - revving high and sounding like a bag of nails....

Removed the thread of material.....car back to normal ;o))