vista4u2

1992 LS400 - According to my service manual, the fuel pump ECU is located on the passenger side, inside the trunk area, at about a 45 degree angle, one foot down from fueling nozzle. But it is not there! Does anyone know where it is?

My problem is this: My car has maybe 25% the power as usual. Starts/idles just fine, but upon excelleration, it seems to lean out, bogs down, and barely goes. Finally gets to speed, but way slower than usual. No check engine light comes on. AND, after a few blocks, my exhaust system is VERY hot. Engine temp is just fine, but the exhaust is screaming hot.

I've changed the fuel filter, swapped out the fuel pump, injectors and ECM, (I have a wreck to salvage parts from , but so far this problem totally eludes me. Any help is much appreciated. Thanks.

LiCelsior

iTrader: (32)

fuel pump ecu is behind the first aid box. you'll have to remove some bolts and clips to get to the back.

ignition coils, depending on which side is burning hot.

vista4u2

Behind the first aid box is where it is suppose to be, but I'm telling you, it's not there.

MeryLexmas

Have you checked the Cat Converters? With a lean condition you should get a code from one of the 02 sensors. Sounds like a clogged converter possibly.

killsnake

not trying to be a ****. If no CEL how do know your vehicle is running lean?

LiCelsior

iTrader: (32)

you can smell it.


if ur exhaust is really getting hot..then search.

vista4u2

I've thought about clogged CATS, but you would the expect a error message to read out if that was the case. Also, I know my exhaust is very hot because of how it smells, how it sounds with excessive pinging and such, and you can even see major heat waves coming off of it.

rburg

I have to agree with merylexmus. Sounds like a clogged cat. As soon as you take off the back pressure will cause those type of symptoms you described. Question. Does your CEL come on when you turn the ignition switch to the on position? Could be that your CEL is burned out. Just a thought. In either case I would expect the CEL to come on, clogged cat or lean condition or whatever other problem.

vista4u2

Yes, my CEL is functional.

MeryLexmas

Easy way too test is to remove the pre-cat o2 sensors and see if performance improves.

JRSLS400

my 92 Ls400 with in the last few months stopped running .after running fine for the six months prior bout a month ago maybe it just stopped cranking it acts like it wants to start but it won't i found the fuel pump .I've changed the fuel pump relay with a another one from a salvage yard here in town. I've sprayed starter fluid in the breather and she cranked and ran until it dissipated .and back to no starting I think its the fuel pump.??? any help appreciated

RA40

iTrader: (6)

Welcome to Club Lexus.

I would suggest this thread:
https://www.clublexus.com/forums/ls4...capacitor.html

JRSLS400

And yes I am reading the threads associated with what I'm asking about. This is my attempt to fix & restore this vehicle my self. There is only one place in this town that has mechanic's smart enough to work on foreign vehicles. The Toyota dealership can't touch it or Won't ?.

JRSLS400

thanks' RA40