Lex4RDNY

Hey folks

I kinda need some advice on my 96 LS 400 that's been causing me some problems. Earlier this month I decide to order the parts to take care of my dreaded egr leak (gaskets still on the way). While do that I figured I would start reading up on the other big problem I had.

My car will do this odd stall/jerk while idling at a light and also when going up hills & accelerating on the highway sometimes. Sometimes it does it more when the ac/heat is on.There was no check engine light so I'm not sure were to start looking for the problem. An old garage mechanic rode with me & felt it & told me he think its the spark plugs or wires or something. I did some searching and came across this thread:
https://www.clublexus.com/forums/ls-...capacitor.html

I notice a few symptoms like the aforementioned stall, My temperature gauge stays at the bottom till I hit it & I do notice the tach/speedometer acting trippy sometimes.

As I type this Im debating on going outside & remove the ecm & check it, but I dont want to break anything because its my only transportation.

But Im really leaning towards it being the culprit.
Forgive me for the wall of text

RA40

iTrader: (6)

Two simple indicators/tests to consider.

Any error codes? There should be if it is stumbling. In that absence this thread on checking the ECU so that you don't have to get into the dash:
https://www.clublexus.com/forums/ls-...-by-yamae.html

Lex4RDNY

Just checked & no codes

dicer

What is a stall / jerk? It kinda dies out then comes back? Good thing is its OBD2 and with a good scan tool someone could likely catch the intermittent problem, by watching various signals. With out the proper instrumentation its all pick and choose guess work and parts swapping. It could be any of the timing sensors, the ecu, ignition modules, wiring and connections to them etc. etc.

If it pulls good acceleration and no miss etc. then any old mechanic should know its not so much plugs and wires.

Lex4RDNY

No it doesn't die, its kinda like a "hiccup" (lol lack of better word) every 10-20 seconds while idling.
I used a actron odbII scanner to check it a little while ago & came across no codes

dicer

If its an actron like mine it reads real time info, what do the fuel trims do? A good scan tool with a scope could record the wave form for the timing signals and help spot a problem.