DFI module "cooks" (smokes, and the gel bubbles)

[Irr]

Series 1 VN. With the VN dfi module and coil pack.

It was missing a lot under load earlier this year. This thread
Error 42 - "spark timing" fault
directed me to replace the dfi module and coil pack. The old dfi module was brownish on the inside, and the gel had bubbled as though it'd gotten really warm. I assumed this was the problem with it and replaced both. This worked - the car ran great for a few days.

It then began missing under load again, and really quicky got much worse. I broke down on the ramp approaching the harbour bridge so I kept my foot down trying to get to the top and off the road. Smoke poured from under the hood.

The dfi module had cooked just like the old one. I've been driving a different car since, but now I need to get it on the road. I've asked around and one mechanic suggested that one of the earth leads might not have been connected when I replaced the motor before all this happened. I've tried to find a stray wire but cannot. I've peeled back as much of the wiring harness covering as I can in case it slipped back up there.

I've tried swapping over the ecu with a mate's one but it had no effect.

Does anyone have any idea what might cause the dfi module to cook like this?

[maginoodle]

is there an earth running from the corner of the dfi to the body? they usually get left off when replacing motor and when you look at it because its not there you wouldnt know its missing.

[Irr]

is there an earth running from the corner of the dfi to the body? they usually get left off when replacing motor and when you look at it because its not there you wouldnt know its missing.

No, there isn't. Does it connect to one of the three bolts on the bottom of it?

[maginoodle]

i cant remember i will have to look tommorow.

[savage1987]

haha well i've had steam but i'm glad i've never seen smoke pour from under my bonnet !!

[mouce]

Did you replace it with a new module or was it a second hand one?

[Irr]

Did you replace it with a new module or was it a second hand one?

Brand new, both coil pack and dfi.

[Irr]

haha well i've had steam but i'm glad i've never seen smoke pour from under my bonnet !!

Just to clarify, it wasn't heaps of smoke, but enough to be noticeable.

[maginoodle]

just had a look. the motor here doesnt have an earth on it but the only spot i could see for an earth to go would be one of those bolts underneath.

[jules]

I've tried swapping over the ecu with a mate's one but it had no effect.

Does anyone have any idea what might cause the dfi module to cook like this?

this happened to me, and i've read it a few times on this board. wreckers have told me it's common. so at least you're not alone

in my case, the ECU was to blame. if you just switched another ECU and the DFI was still smoking, that's not surprising - it's too late by that stage.

in my case i went and got the ECU reco'ed, as well as VP-style DFI and coilpacks and it was all OK after that.

my advice would be to have your ECU tested. Petroject in melbourne do this and they accurately diagnosed my unit as faulty. they even fixed it and it ran sweet straight away after i replaced stuff as described above.