1JZGTE revving up & down to 2500RPM on startup

[oldcorollas]

the hunting was caused by the trans ECU?

[CrUZida]

But you said you already tried another ecu ?

And Stu, the 1JZ uses a combined ecu.


Also, with the sometimes start thing, if you rotate the key slowly and stop moving as soon as the starter motor is engaged, sometimes the accessories contact wont be broken. I frequently start my car without the radio turning off.
That and the fact that I doubt the ecu actually looks at the MAP readings during cranking.

[Jabtronic]

I did try another ECU.. the iscv hunting was only on the A/T ECU which is the one I was using when it started happening.. then I went and bought another M/T ecu but it wasn't starting either so I disregarded the ECU's as the problem.

It starts every time now.

[Hengsta]

Would we be able to fix the rev hunting on the ECU?

really keen to get mine fixed.

[Jabtronic]

ARGH.. I've just gone to start the car before and it's rev hunting again.. I havn't touched anything... FUCK this is really starting to piss me off.

[Hengsta]

When you find out what the problem is, let me know mate.

[skin]

well rule out the FCD, i just wired mine into ACC and its fine

[Jabtronic]

Yeah my engine is all shades of fucked.

ISCV working again now, instead the ECU isn't reading map sensor (removed FCD for now), the car runs like a sack of shit, can't boost.. unplugged map sensor while engine idling and no difference in revs etc.... :cry:

Tried another map sensor today, and another throttle-body with TPS.... I give up

I'll check the continuity of map sensor wires to ECU tomorrow.. I'm certain I'll find no problem there though

[CrUZida]

Join the club on engines doing stupid shit for no reason.

I've got one bank leaner than the other (1UZ)

[JZX083]

Dude,
Have you got the charge circuit working correctly ie: running 14.4v when running? Are you trying to start the car with a flat or dying battery??? Also if you can jump start the car from cold start and see if it idles fine when you do that. My ECU died after i drove my car on the battery cause the altenator shit itself.

[Hengsta]

Dude,
Have you got the charge circuit working correctly ie: running 14.4v when running? Are you trying to start the car with a flat or dying battery??? Also if you can jump start the car from cold start and see if it idles fine when you do that. My ECU died after i drove my car on the battery cause the altenator shit itself.

Got a feeling my altenator is on it way out.. My battery gets flat sometime and its pretty much a brand new battery.

Either is my Starter motor fucked or my altenator is on its way out.

Nearly every morning i have trouble starting my car (either it dosnt turn over or it turns over but dont start) but when the car warms up it will start every time very weird id say.

[Jabtronic]

Dude,
Have you got the charge circuit working correctly ie: running 14.4v when running? Are you trying to start the car with a flat or dying battery??? Also if you can jump start the car from cold start and see if it idles fine when you do that. My ECU died after i drove my car on the battery cause the altenator shit itself.

Well yeah. that's what happened last year on the way back from QR.. alternator stopped charging somehow and battery died on the way home. Got the alternator rebuilt even though the guy told me it bench tested fine, and the ECU seemed fucked so I bought another which worked.. for a while.

I checked that the alt is charging today whilst the engine was playing up and it's giving a healthy 14.4~ volts That is an area of suspicion though. Maybe I need to recheck the power at the ECU. Argh I'm getting sick of checking things

well rule out the FCD, i just wired mine into ACC and its fine

Mine's a bit different because isn't wired straight to ACC, it's wired to a fused battery line (through a custom fusebox) which is switched on by ACC using a relay. So there would be a slight delay cause by the relay switching the power. BTW should probably mention this fusebox now only powers my digital gauges, HKS boost controller and stereo so it shouldnt have anything to do with the problems I'm having.

[Jabtronic]

I wonder if it's anything to do with having the battery in the boot? I wouldn't think so though.

On the battery I've got 2 earth leads, one goes to rear strut tower, other goes all the way to engine block, passenger side engine mount. Then another thick lead from engine mount to chassis and chassis again.

And a positive lead going to the starter motor, then original power lead going from starter motor to fusebox.

Shouldn't be any problems with this setup.. right? All the leads are welding power cable.

[Hengsta]

Any news yet mate?

[ZZT231]

I have had a similar problem with my engine. I know that the ISCV isn't powered up and is stuck open so a mate opened it up, wound the thing shut so at idle in when cold it's impossible to drive, but once warmed up it drives great.

I know there is a wiring issue for it not to power up... I just don't know what wires are missing to make it work...

Cheers.