1JZ error code 31 and no power to fuel pump?? (edit: now coil problems)

[Jabtronic]

Using a multimeter (which was too slow obviously) the 5th coil plug seems to act the same way as the others? Yet there is absolutely no spark, whereas all other 5 coils/sparkplugs are nice and bright. (EDIT: I swapped coilpacks/sparkplugs around to make sure it wasn't the individual coil or sparkplug)

I guess from now I just need to test another ignitor?

I've been thinking could the ECU or ignitor possibly have dodgy ground connections? Because all the ground connections for the ECU are attached only to the engine and then straight to the ECU arn't they? Would hooking up a few more ground points help?

[Jabtronic]

Got the car running properly today, all I did was ran another negative cable from the battery (in the boot) to the engine, and now it idles and runs fine
After all these months of stuffing around with it lol, although I'm sure everything else I've checked and fixed up (ECU caps, coilpacks, fuel pump relay circuit etc) have made a difference as well.
Cheers

[rob_o]

Interesting...

I bought a Cressida with 1JZ with engine problems. Ran good when cold, then ran like a dog when warmed up.

Since then, I have pretty much rebuilt the motor and did a big single conversion while I was at it. Car starts up fine and runs well, then we went to put it on the dyno to check AFR's. As soon as it hit boost, AFR's went down to about 8-9 and black smoke coming from exhaust.

To me, seems like a misfire and has fouled the plugs (4/6 are black). I'm also going to try connecting another negative terminal from battery to the engine.

[Jabtronic]

Yeah lol, there's been so many stages I've gone through trying to diagnose this starting problem

First thought it was ECU, replaced capacitors and it started... then died 5min later..
Swapped in a borrowed Blitz Access ECU - and it starts.. so..
Bought another ECU - doesn't start
Glue up coilpacks - It starts! runs on 5 cylinders though
Checked the wiring, was about to replace the ignitor
Wired another earth lead to engine from battery in boot - starts and runs fine

Then the other day I decided to test my first ECU to see if there was anything wrong with it, car didn't start... ok.. put the second (working) ECU back in.. still doesn't start.

So it must be in the wiring plugs... I found that one of the wires in one of the ECU pluggs is loose so it's not seating properly. (See thread about that here)

It was probably just this loose ECU plug pin all along Every time I bumped the wiring to the ECU made it work or not work.

[Ribfeast]

Bizarre!! Good to hear you sorted it all out

[Jabtronic]

Yeah, its starting every time now however still idling a bit strange, and seems to be running rich.

When I tap the accelerator while idling the car almost stalls when the revs drop back down, anyone know what this could be?