SC400 Start and Stall

[jchotovy]

I have a 1992 SC400. It always has started and ran fine. Recently I took it out of storage and shortly there after it started to stall and start hard.
It starts and runs fine when cold. It usually gives me problems after it has been warmed up and I try to start it after it sits for 15 to 30 minutes. It is intermintent. If the cars sits for a couple of hours it starts and runs fine again. Once it finally starts, it runs fine. No problems with gas mileage, no smoke. Any ideas would be helpful.

Thanks John

 

[Zuffen]

I'd start by checking the cold start sensor on the front waterbridge. Check it doesn't have dirty connections.

 

[Damien]

This was discussed at soarercentral.com a while ago and no-one came up with a positive answer but one guy who had the problem found that when we changed ECU's the problem stopped.

http://soarercentral.com/sc-forum/messages/126/33280.html

See if you can borrow an ECU for a few days perhaps to see if it goes away.

 

[jchotovy]

Gentlemen,

Thanks for the swift response. Don't mean to sound stupid but what is a ECU?
Water brige? I am some what of a Lexus beginner. Have had the car since '99 and have had no problems with it untill now. Just have been changing filters, oil etc.

Thank you John

 

[WDoherty]

you might try clublexus.com, they are pretty good with diagnotics in thier forums.

 

[jibbby]

ECU - Engine Control Unit....This is what controls the Air/fuel mix and all that other fun electrical engine stuff...In laymans terms it is essentially the brain to the engine... It is a little metal box not much bigger then your entire hand and this little ECU box is mounted under the carpet on the passenger side feet area...Pull back the carpet at the top and you can't miss it...A bunch of plugs with wires connect to this ECU box and you can see wires going everywhere, like to sensors, controls, etc... you name it...Hope that helps...

Hot starts stink good luck!!!....In the older Chevy I use to have and work on the headers/exhaust would heat up so much as to effect the ignition wiring or electric current system going to the starter motor and cyliniod, etc...and would cause problems when starting the engines hot.... "hot starts" The Lexus Sc's wiring is insulated pretty well and the ignition wiring is far away from the engine hot zones.. but who knows.. I would start by inspecting all wiring. connections, sensors under the hood.....If nothing is found then I would get an engine Diagnostic check at any import mechanic shop, maybe the computer test or mechanic can tell you if something is a miss..shouldn't cost you too much for a computer check.......Does your check engine light come on?

If that all fails then try swapping in a new ECU...Pull one at a local junk yard for a couple of hundred bucks and plug it in...That is what I would do....The ECU swap would be my last resort... No, actually the dealer would be my last resort...Good luck, See ya

 

[Lextech]

Is it possible you might have some summer formula oxygenated fuel? We get a rash of these type complaints from customers every season.