Club Lexus

1jhazzard · 03-02-07, 03:27 AM

Ok, i searched through 9 pages of pages from the search function but couldnt find a problem quite like mine. i have a 93 sc3 with the 1jz swap done to it. Today i started the car for the first time and it started and idled fine about 1200 rpm. which is about normal for a cold engine and the first start. well it ran for a few minutes to operating temerature i ran my errand and came home. well latet tonight i started it up and it once again idle'd higher cause it was cold but when it came down it dropped to about 200-300 rpm. and that is where it idles. it stays running but the idle seems super low. I think it is the alternator. the headlights become brighter when i accelerate and the heater also picks up speed from accelerating. the battery was replaced a week or two ago so that is brand new. there is only about 60k or so on this engine. anybody else have an idea or do you concur with my thinking of the alternator?

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Z3NK1 · 03-02-07, 07:17 AM

I just had the same thing start happening to me yesterday, except mine is idling around 500rpm, barely sounds like the engine is running. Spent all night searching the forum and came to the conclusion that it was the fuel pump ecu. Motor takes a few seconds of cranking before it starts as well so it seemed like the obvious fix. Anyways I had another fp ecu and I installed it, but nothing has changed

Back to the search button, oh well I hope that saves you a few bucks by going out and buying another fp ecu lol. Next thing I'm going to try is playing around with the idle air control.

btw I have a 1jz as well, and I doubt it's the alternator because the reason your lights dim etc is just due to the lower rpm not allowing the alternator to charge the same power as it does at higher (normal) rpm so everything dims.

sc250tt · 03-02-07, 07:20 AM

i have a 1j also but never had that problem before it could be a loose vaccume line or the iacv needs to be cleaned goodluck

shlounek · 03-02-07, 08:03 AM

Did you check your vacuum lines, my MAP hose always pops off and car starts to idle low and rich. Pop the hood plug the vacuum line in and presto.

But on the 1JZ's hoses love comming off so you will need to zip tie everything down

The dim lights could be from the low idle.

As a temp solution just adjust the little idle screw to a lil bit higher.

1jhazzard · 03-02-07, 01:51 PM

yeah highyl doubt on mine its the fuel pump ecu. mine cranks right over and starts its just idleing low. the other thing is even hwen my car idles fine the headlights still get brighter when i accelerate and the heater still picks up speed as wekk.

1jhazzard · 03-02-07, 05:41 PM

ok so i was loooking at the throttle cable and the throttle body this afternoon trying to figure out this problem and i reseated the throttle cable and now it seems to have gone back to its normal idle. when wamr its idleing between 550-600 so i don know. i'll post back if i have anymore problems