Mk2 Cavalier 20SEH SRi130 wiring

[Dougie_SRi]

Hello all,

Lynz's Nova engine doesn't like running on Mk3 Cav management (same fault codes come up no matter what I change), so I've swapped the loom the one from my Mk2 SRi 130 and amazingly, there no faults.

Only thing is, I can't get the pump to run properly. Connecting the red/blue seems to do nothing, but if I run the wire from the pump to the thick red/blue at the fuel pump relay, then the pump will run permanently - the car starts and runs fine in this case but it's not ideal. The relay works, and the contacts are clean.

Is there another wire I need to connect? There's a black/white which doesn't seem to do anything.

Cheers

[Lee]

Hello all,

Lynz's Nova engine doesn't like running on Mk3 Cav management (same fault codes come up no matter what I change), so I've swapped the loom the one from my Mk2 SRi 130 and amazingly, there no faults.

Only thing is, I can't get the pump to run properly. Connecting the red/blue seems to do nothing, but if I run the wire from the pump to the thick red/blue at the fuel pump relay, then the pump will run permanently - the car starts and runs fine in this case but it's not ideal. The relay works, and the contacts are clean.

Is there another wire I need to connect? There's a black/white which doesn't seem to do anything.

Cheers

I think you'll find the fuel pump runs from the blue wire in the same bunch you got the red/blue from mate. I had the same problem with an early XE loom last year.

Is the switched live wire black on the loom, or black with a yellow trace?

[Dougie_SRi]

Switched live is black.

Will report back in a bit with progress - cheers for that, will see if there's a blue.

[Lee]

Looks like we need to add onto the guide in articles than early SEH's use black/white as the pump feed :)

[Dougie_SRi]

Yep, black/white it was! How did you know? :D

It runs now, but oddly, I had to cut the bottom of the lugs off the throttle position switch to get it to move round far enough to click.

Also, still getting two fault codes: 73 AFM low voltage, and 65 CO potentiometer low voltage. Doesn't seem to affect the way it runs though. I'll clear them and see what it does. I don't get what it means though if the AFM isn't getting enough volts?

It'll tick over and rev up happily now, but misfires badly under load so I think a new dizzy cap and some plugs are in order.

Getting there, slowly!

[meritlover]

sounds like the CO pot is out of adjustment, open circuit or faulty.
this will be affecting the mixture, which will be driving the O2 sensor Voltage low and giving the second code.

....just a thought.

[Sloth]

try a new t/b i had same codes, and the body was leaking air in on the shaft, which was also worn where the pot goes.