Slimls400

Bought a 91 ls400 couple weeks back and the story i got from the guy was that he parcked it and let it sit for 6 months and when he went to get in it it wouldnt turn over. So he pulled the starter and took up to have it tested. Tey said it was bad so he bought a new one put it in and it turned over but wouldnt fire. So i bought it from the guy not running. I went thru everything, checked the wires, coils, put new caps, rotors, ignitors, crank sensor, ecu, circiut relays and still cant get it to fire. Im thinking the camshaft position sensors might be bad but i dont know for sure if they are. Anyone know of anything i can check that it might be?

BobN54

Some basic trouble shooting suggestions:

Is the ignition system producing a spark? - Test with a timing light or an inexpensive inline spark tester.

Is there fuel pressure?

Is the timing correct? - Do the distributor components you replaced have the factory notches etc. so they cannot be install backwards?

Is the airbox unobstructed? - no rodent nests, etc.

Slimls400

All the parts ive replaced cant be put in backwards so far. I put a volt meter on one of the coil packs an when i cranked it only showed like 12 volts, shoudnt that be hire? Nothing wrong with the air box checked that. I mean i even put in new ignitors and still nothing. Could it be the cam senors? And how would i tell?...im new to lexus, any other car ive had i was able to run thru and get it running like that. This im stuck on and lexus company dont help

anthrax144

Maybe too obvious but is the battery still good?

Slimls400

battery is fine...its got like 12.36 when you test it

PureDrifter

iTrader: (10)

check for spark....

Slimls400

thats the problem, im not getting spark....im trying to figure out why im not. like i said i replaced cranks sensor, ignitors, caps and rotors, ecu, coils are fine, new circuit relays. im at a stand still. thinking its the camshaft sensors but not for sure

Importera

I fixed my friends a few years ago and it turned out to be the ECU. We changed the ignitors and all kinds of other stuff. But, The ecu was the problem.

PureDrifter

iTrader: (10)

so trace back. no spark at the spark plugs, check the distributor to see there's spark coing of it. how about spark right off the coil? no spark on the coil? test for dead coils. coils test out? check the cam/crank angle sensors.

IS350jet

The starter in those cars is buried inside the engine. You have to literally pull the engine (top half) apart to replace it. My guess is, this seller probably didn't put things back together properly, possibly with major vacuum leaks. It's not a simple job. The fuel system may need to be bled.

LScowboyLS

if you have to go back in to test or replace the starter, that job is such a pain that I consider that if a starter or knock sensor needs replacement, that you never do one with out doing the other, since you are already there!

chuuck1e

Gas can go bad after six months or so, and will not combust. Maybe that is the problem.

Slimls400

i did pull the whole top end part to check the starter and make sure that nothing got left unplugged when he did the new one, come to find out there was nothing unplugged so i put it all back and now have pulled one of the cam sensors and it appears to be fine along with the other one. So im back to square one i feel like. im pretty much outa ideas to be honest, ive checked and replaced everything that would deal with spark and feel like its all working except the fact that im not getting fire. i bought only one new plug because all these are pretty bad, but im still not getting spark outa the new plug.

Slimls400

i thought it might be the fuel but when you pull some outa it and throw a match in it, it catches fire. so its obviously still combusting

mspearl95

How about the fuel filter?