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View Full Version : C20xe not starting suspect wiring.



Davidedwards
21-05-16, 05:49 PM
Hi any help/advice highly appreciated. To cut a long storey short I purchased a Corsa c20xe a week ago purely with the intent of butchering it to do a conversion on one of my novas. Heard it fire but it then cut out so I assumed it would need a service as been stood for a few years. For the past week I have been trying to get it to fire with no luck. Fpr works, it's got spark there's pressure in the fuel rail. The injectors have a constant live and constant ground. Can't work out why there's a constant live to the injectors. I'm unsure it's supposed to be this way and the ecu cuts it out as and when. Or is the ecu knackered. When I unplug the fpr the injectors loose there constant live as they should but the constant negative stays at the injectors. And only goes when I u plug the ecu. Any ideas where I'm going wrong. Or things I havn't checked

meritlover
21-05-16, 07:28 PM
The injectors are always live and the ecu pulls them to ground to fire.
You have to check the usual mechanical things first before you condemn the ECU

Davidedwards
21-05-16, 08:09 PM
Hi I'm scratching my head with it. It's the first xe ive had. I just can't get my head around why there's a constant live and negative going to all injectors. I have no idea whether it's meant to be this way or not? Anyone's wisdom is highly appreciated.

Davidedwards
21-05-16, 08:13 PM
I've checked the crank sensor unsure of Hal sensor but I read if I unplug it the the ecu will fire the injectors like a 8v? But still nothing

Will F
21-05-16, 08:51 PM
Fpr... Do you mean the Reg or relay?
im assuming the latter. If you haven't swapped it, do that first.

Davidedwards
21-05-16, 09:10 PM
Yes I mean relay. I'll order one today. Thanks for the advice. I've just run new earths to just about everything. So atleast I can eliminate it being a earthing problem.

Davidedwards
22-05-16, 06:31 PM
Update. I've played around with some wires and separated the engine wiring from car, I run some new wires for the 3 direct from the battery and surprise surprise It runs, just doesn't idle. It will stay alive if I keep the revs on the accelerator. But will still die after about 5 seconds. Doesn't keep pressure in the rail when the engine is not running. Is it supposed to do this? Anybody got any ideas? I'm just waiting for a new fuel pump relay and crank sensor to turn up. Any ideas?

Davidedwards
28-05-16, 10:55 AM
Fixed it. Everyone can go back to there normal lives now And stop worrying about me!! Haha
if anyone else gets stuck in the same situation. It's safe to say it was not the ecu, injectors,relay or even the crank sensor. that was at fault. Although I now have shiny new ones. It turned out to be a corroded pin inside the ecu plug and a corroded fuel pipe inside the tank. So instead of the pump sending the fuel to the engine it was creating a waterfall in tank. It was a nice display but not practical seems as tho I'm one of those guys who likes my engine to run