jtc3200

I just took my car down to PepBoys to have them check on the engine and fuel system. Everything checked out well from fuel Pressure to Spark plugs. The guy said the engine runs really fine and could not find the problem. He was actually starting engine just fine everytime.

Then as I was leaving, the problem surfaced again and the car wouldn't start. He immediately checked it and told me it may be the anti-theft device (original manufacture) that's preventing the engine from firing up. He fliped the key and reinserted, cranked and the engine fired up immediately. So his recommendation was for me to bring the car to Lexus Dealer and have them check on the antitheft security system.

Any ideas? I guess I may just have to bring it to the dealer.

PureDrifter

iTrader: (10)

you took your car to pepboys


good luck in life.

Sanpete

The immobilizer (anti-theft system) doesn't fit your symptoms as described in your first post. It prevents any power from getting to the starter.

ttyR2

Does the engine have a cold start injector? Or is that only for engines with TBI systems?

sonyman

It does. 1990-1994 engines have a cold start injector connected to a thermostatic time switch.

PureDrifter

iTrader: (10)

iirc the immobilizer allows the car to start....barely, it kills fuel and spark.

jtc3200

So does the immobilizer in my 1994 LS400 actually kills the electricity to the starter and prevent cranking all together or it kills fuel and spark and allows starter to crank and the engine to barely start and choke a few times before it dies? Because my engine does choke and barely starts when I am having trouble starting it.

Is there a way to turn the immobilizer off? or disconnect? or disable it? I know just turninig off the remote key entry is not enough.

Can the problem be with cold start injector?

jtc3200

Actually the problem even starts to happen when I try to start the engine warm now, like my car sitting for about an hour during the day. It's completely unpredictable now. Sometimes engine fires up right away first time in the morning. Sometimes it takes 5 tries and the engine would choke and barely start before I finally fire it up after car sitting just for an hour during the day.

I can really use some help.

DementedSc

I have the EXACT same problem with 94 sc400. When it happened the first time, i took it back to the dealer and they had their technician look at it and drive it for a few days an it was fine. Drove it for a few days an it was fine, went to work today and as i was parking it shut off on me. There taking it back and sending it to get another mechanics opinion on it. Theyve already replaced the fuel pump and fixed the fuel guage and the problem is still occuring. Anyone who can help us out, ill appreciate it and so will the guy who has this problem as well

PureDrifter

iTrader: (10)

hrmm, the first year LS400 to have an engine immobiliser system was 1997.


you dont have one.

jtc3200

You're right. It's a starter kill. The starter wouldn't even crank when the alarm was triggered.

The frequency of this problem is getting worse. I made an appointment with Lexus Dealer next Tuesday Morning. I hope they will be able to figure it out. I will keep you guys posted.

sonyman

No. All LS400's have an immobilizer. 1997+ have an additional transponder-linked immobilizer feature that will allow the starter to operate, but prevent the engine from actually starting if an unauthorized key is used.

The starter kill is the immobilizer. However, the immobilizer on 1990-1996 LS400's will prevent the activation of the starter circuit, preventing the starter from operating at all.

PureDrifter

iTrader: (10)

i think of an immobilizer and a starter kill as two different systems, so when i say immobilizer, i speak of the ECU not giving fuel and/or spark.

sonyman

I see your point, but just for technical accuracy, I'll continue to refer to the early system as an immobilizer, as called so by Lexus.

jtc3200

Brought by LS400 to the dealer this morning. Of course it took me about 3 tries to fire up the engine and the dealer didn't have any problem firing it up. They gave me a loaner car and will let me car sit for a while to see if they can duplicate the problem. Told me it should be either the fuel pump, cold start injector or the starter. There was fuel pressure, so the guy is leaning toward the starter. He said that the starter may be cranking ok but not engaging sometimes. he will let me know when they can duplicate the problem.

How much would be a fair charge to replace a starter or a fuel pump or a cold start injector? I will keep you guys posted.