1GGTE ECU overheating

[Jabtronic]

Hi, this is basically a follow on from my previous thread where i was trying to figure what was wrong with the 1G in my Z20 Soarer. (here)

It seems that my car will run fine at first... so it will idle fine etc (although has a bit of a miss) and drives sorta ok (think timing is still out slightly) but I can only drive it for about 5minutes before the engine dies and doesn't start again.
I've found that the ECU is getting very hot, so it must be shutting down due to the heat. It stops providing power to the injectors, everything else seems to be ok though (spark, fuel pump etc)

I don't think it's specifically ECU related because I've tried 2 so far and they both get hot, so I figure it must be the wiring? Maybe a short in the loom somewhere..?

Just wondering if anyone has had a similar experience?

[Admiral coFF33]

ECU's should only get warm .... not "hot"

[VasH]

Maybe check all your grounds/earths and clean up the contacts? same with all the fuses and relays. Doesnt sound like its gonna be easy to solve. Might need a auto electrician?

[EldarO]

gonna be a nightmare to solve as its obviously not the ECU thats crook.

id suggest just checking the resistance of power and ground wires to start with, then go from there i guess...

[CrUZida]

The ecu does not power the injectors.
The ecu only powers things like AFM, TPS, etc.
All the high powered items are powered from the ignition relay (switched by the key).
All the lower powered items are powered from the EFI Main relay (switched by the ecu)

[Jabtronic]

Yeah I'm really not looking forward to mucking around with the loom... maybe I should just ditch the lot and go 1JZ already

It's getting hot as in 'left out in the sun' hot, basically it gets too hot to keep my hand on the lid. I've opened it up and there's a very light sooty burn mark on the underneath of the lid but I can't see where it has come from. It was the same on both ECU's.

[Admiral coFF33]

Many 1G's around

ECUs are fucking ismple to get to
get a friend to help u
swap ECU with a knowen working one
no more issues ?
then replace dogshit fucked ecu ?
?????????????
win the championship

[Jabtronic]

Did you read my other thread? this is the 2nd ECU I've tried, both are doing the same thing.

[EldarO]

he's tried two already John, read a bit yo

[VasH]

burn marks thats not good. Hope mine is still ok lol

If you want jarrad ill rip the loom outta mine (its already half out) and come down your way say weekend after next? and give you a hand. Hopefully both ecus arent stuffed.

[auto351]

Hi, have you checked your injectors (resistance/impedance)?
the ECU energises them, there maybe a problem with the internal winding when they warm up
if there is an ineternal short CCT this may cause the ECU to heatup after a short while.
A before and after test using a multimeter should verify there condition .

[CrUZida]

I'd start with the injector resistor (assuming you have one).

[thechuckster]

If it doesn't have the resister pack, then probably courtesy of the lowZ injectors your ECU is trying to grounds lots of Amperage thru the injector drivers and they're transforming themselves into molten lumps of plastic.

I'd say you've let the electrical smoke out of another ECU and it's time to re-check a few things.

What are the injectors out of (which gen engine) and were did the wiring loom/ECU come from?

Also, put a multimeter across one injector and report back with the resistance.

Someone might be able to confirm injector resistance: gen 3 are highZ and gen2 are lowZ ?

[JZA70R_92]

I know that with my GEN 3 there is no resistor pack! Lime Green Injectors

[Jabtronic]

If it doesn't have the resister pack, then probably courtesy of the lowZ injectors your ECU is trying to grounds lots of Amperage thru the injector drivers and they're transforming themselves into molten lumps of plastic.

I'd say you've let the electrical smoke out of another ECU and it's time to re-check a few things.

What are the injectors out of (which gen engine) and were did the wiring loom/ECU come from?

Also, put a multimeter across one injector and report back with the resistance.

Someone might be able to confirm injector resistance: gen 3 are highZ and gen2 are lowZ ?

It's all Gen 2 engine/ECU/loom in my GZ20 soarer. No injector pack.

I'll test the resistance tomorrow, will also clean up some of the manifold grounds etc.

And thanks for the offer Vash, I don't really want to get the stage of swapping looms etc, for that much trouble I'd just throw a 1JZ in there instead. And yeah, I hope your ECU is still ok but if it's fucked now I'll reimburse you for it