C20XE From Nova Into Corsa B problem

[vx kev]

Hoping that someone could shed some light or possibly point me in the right direction, and yes going by the title some of you may say ive already gone in the wrong direction lol
I stripped the engine out my 1989 project car having just completed a couple of track days with it, all was ok and was running perfectly fine before removing. Ive now put this engine into a mates Corsa B. Had a couple of issues with plugs and distributer cap etc. to begin with but once a good service was carried out the engine was running fine for approx 100 miles.
The next day it wouldnt start, plugs were soaking in fuel so disconnected fuel pump and it eventually fired and was revving up at 4000 rpm. Now ive been through the whole process of elimination changing cts, cts wiring ok, afm, injectors, coil, fuel pump relay, ecu and even the loom, basically anything i could change with known working parts. Ive checked for air leaks, checked and replaced all vacum hoses but still nothing has helped.

To me it seams that something is casuing the injectors to be constantly open as i only need to buzz the fuel pump momentarily to get enough fuel in for it to run for about 5 minutes.
Never has this sort of problem before and im sadly stumped on what it could be so any help would be greatly appreciated.

[staggy_gsi]

If the injectors were constantly open i doubt it would start up at all, it would just flood and put the spark out. Is pressure reg ok? Maybe making far too much pressure?? Strange one...

[meritlover]

ecu injector drivers might be fried. since youve changed everything else there isnt much other than the reg. check the continuity of the loom in case something is dragging it down to eart. but first use a meter to see if the injectors really are on all the time.

[stuartp]

I know you say you've checked the wiring but mine had the same symptoms and the wire to the cts had basically snapped 4" up the loom from the sensor I only found it when I cut back the loom sleving. Renewed the wire and it started staight up and idled perfectly.

[vx kev]

If the injectors were constantly open i doubt it would start up at all, it would just flood and put the spark out. Is pressure reg ok? Maybe making far too much pressure?? Strange one...

It splutters then nothing, so i disconnect the fuel pump and then turn it over. It eventually fires and runs with no fuel pump for a rediculous amount of time. I havent changed the regulator yet which is about the only thing left to try so thats next on the list.
Wouldnt have thought a knackered Reg would make it chuck so much fuel in though?


ecu injector drivers might be fried. since youve changed everything else there isnt much other than the reg. check the continuity of the loom in case something is dragging it down to eart. but first use a meter to see if the injectors really are on all the time.

It does this with 2 different looms and also 2 different ecus, both running perfectly fine in other vehicles. Its just the fact that all was ok for a couple days and then this.
I have heard of corsa b's having problems with the car loom at the rear of the engine rubbing through as it is rediculously tight but that would require dropping the engine out again to check!


I know you say you've checked the wiring but mine had the same symptoms and the wire to the cts had basically snapped 4" up the loom from the sensor I only found it when I cut back the loom sleving. Renewed the wire and it started staight up and idled perfectly.

Yeh cut the wiring sleave for the cts right back to check it and all is ok, the 2nd loom has had this renewed previously so still total head scratcher.

Thanks for your pointers so far guys.

[meritlover]

have you checked to see what the injectors are doing when its flooding? are they constant 12v or switching? what is the fuel rail pressure measuring?

[vx kev]

Not yet, will need to get a meter and get a pressure guage connected so thats tomorrows job. Obviously when working correctly the injectors should be switching if im right in thinking?

[meritlover]

.... Obviously when working correctly the injectors should be switching if im right in thinking?

it depends where you measure the voltage. i cant remember if the C20XE is held high and pulled low by the ECU or if its switched high. you would have to check a wiring diagram

[vx kev]

I couldnt get a guage to fit the rail to check the pressure so i replaced the Fuel regulator with one i know works but still no difference, i then treated myself to a new test meter and checked the injector voltages. On all 4 the blue/red wire is showing 13.7 volts when running (same as battery) and the 2nd wire into each injector (brown/green no4 - brown/white no3- brown/yellow no2 and brown no1) they are going up and down from about 9 volts up to 13 volts.
I even added a couple of extra earths to the injector loom in a bid to solve it.

Also both idle controls valves that i tried when checked the mechanism was free and easily moved, i put one on that i couldnt move which has now brought the revs down to normal levels onces it running having pumped some fuel in.

Tried the other ecu and 3 fuel pump relays again but it still shows the same figures as above, so im thinking that the injectors look as though they are open near enough all the time. Literally connect the fuel pump wire for 1 second and it chucks in enough fuel for it to run on its own accord for atleast 5 mins, although when you try to blip the throttle quickly it wants to die but will start back up again until the fuel has burnt off.

No fault codes either!

[dc1984]

Is it not obvious kev mate.....



.....the poor engine wants to go home to the nova lol

[vx kev]

Is it not obvious kev mate.....



.....the poor engine wants to go home to the nova lol

Dont tempt me, wish i'd just left it there now :cry:

[dc1984]

lol a man of your capabilities will soon have it sorted and flying round knockhill.

[vx kev]

So still no further on with this. Stripped the loom off the engine and stripped all the sheathing back to check all the wires, no real issues to report there so tidied it up and taped it all back up again. Having cleared the codes on both ecu's im now geting code 94 which is Hall Sensor Voltage High. Now ive had Hall sensor faults before but they have never stopped an xe from going before. Having now checked absolutely everything i can think of i can see no reason at all why this is still chucking so much fuel in. Timing etc. is spot on aswell. Could it actually be the engine thats at fault and not a management issue? Anyone any more ideas please?