20xe conversion running issue

[AndyRandz]

Hi guys just wondering if anyone has any fresh ideas to help me out...

I've just fitted a 20xe into my 1.2spi nova. I've owned a couple of Xe/Let novas in past but never converted one myself.

Everything has gone pretty smoothly following various old threads, guides and some general logic and common sense.

Now I've got her all wired in and running. The issue im having is it won't actually stay running. It starts on the key every time and immediately cuts out. Any throttle applied kills it even easier. My spark is really strong and there is good fuel pressure at the rail. I've switched out the fuel relay/hall sensor and even tried running a live to fuel pump. Same issue. Tried wiring in the eml light for some flash codes but I don't have any live feed coming out the wire. This does raise some eyeballs towards Ecu fault. The initial Ecu that came with the engine I bought won't even spark but I had another at hand anyway which I had off a previous running car. I'm a bit miffed if I'm honest. I'm a bit of a newbie with auto electrics but do have access to auto data loom diagram and good basic logic.
I'm at a bit of a dead end and could do with some fresh input and maybe a few pointers before I call in a auto elec and pay out my a***!!

Thanks
Andy

[AndyRandz]

Just realised the electrical section might have been more appropriate!

[millworm]

could still be a weak pump try a different one if you can, I assume it's not the spi pump your using? Was the engine running ok before? could also be crank sensor or timing out. would check fuel pump first though, check resistance in the feed wires to the pump are low as well as had a few escort rst and sierra's have weak pump symptoms when in reality it was knackered old wiring

[AndyRandz]

could still be a weak pump try a different one if you can, I assume it's not the spi pump your using? Was the engine running ok before? could also be crank sensor or timing out. would check fuel pump first though, check resistance in the feed wires to the pump are low as well as had a few escort rst and sierra's have weak pump symptoms when in reality it was knackered old wiring

Hiya pal. Pump is a brand new Astra GSI in tank I've only just fitted. Fuel pressure at the rail seems fine. I've just had a fresh belt put on and we're 100% timing is ok. I do not know the history of the engine. I bought it off a guy on here who is helpful enough and seems genuine. Crank sensor is something we haven't tried but I didn't think it would actually be the issue due to it actually fires off the key everytime but correct me if I'm wrong.

Just having a hour or two on it now. Power from Ecu to injectors all good, fuel relay all correct.


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[Southie]

Could be the timing, is your a dizzy c20xe? Also check the cam timing isn't out.

[AndyRandz]

Could be the timing, is your a dizzy c20xe? Also check the cam timing isn't out.

I've tried two different dizzys as first one wasn't giving me a spark whilst engine one was running only when cranking. Second one was off running car and gives me good spark whilst cracking and continues whilst running. I'm going to switch out with another Ecu tomorrow and try source a crank sensor see if that is faulty


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[AndyRandz]

Still no luck guys.. I know now it's 100% injector related. Will run fine with easy start in the inlet.

The power cuts once car starts. Fuel relay switching (both switches), tried 3 separate Ecus, doesn't appear to be any breaks in wires. Brand new coolant temp sensor and crank sensor fitted today. 2 separate dizzys/hall sensors tried. What else could drain the power from them on start up??

I'm going to clean both Earths on gearbox end of the rail tomorrow and see if that's throwing the power off. Asides from that I am well and truly at a dead end.

Only thing that I can pick up on is on the diagrams I've seen about there is another earth cambelt side along the fuel rail. But there is not on on my 20xe loom. An neither does it look like there's ever been one on the loom. There is no hole in the plastic cover along the fuel rail. Just 3 holes all occupied for the wires which go to MAF, TPS and knock sensor and idle control valve.

Any input guys?? Be much appreciated as its really quite annoying now


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[Southie]

Did the old car have an immobiliser on it? Was the engine running right when you got it?

Have you checked the actual timing on the cam belt?

[AndyRandz]

Did the old car have an immobiliser on it? Was the engine running right when you got it?

Have you checked the actual timing on the cam belt?

No immobiliser on the car and I couldn't tell you on the car the engine came from but far as I'm aware the 2.5 motronics weren't immobilised and I've got 3 separate Ecus here I've tried. Far as I'm aware that won't be the issue, correct me if I'm wrong.

Timing is fine I've double checked and had a second opinion. Like I said engine runs sweet as a nut when I apply easy start into the inlet


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[paul080803]

What code is on the ecu?

Lambda sensor or not?

You are correct, 20xe loom has 2 earth's from the inj rail not 3 like the later looms.

Tried a different maf sensor?

[AndyRandz]

What code is on the ecu?

Lambda sensor or not?

You are correct, 20xe loom has 2 earth's from the inj rail not 3 like the later looms.

Tried a different maf sensor?

No lambda sensor.
I have tried f and g series Ecus to same effect.
No I haven't, that's about the only sensor I haven't switched out.
Doesn't make any difference when connected or disconnected as I've tried that to see if there was any impact.


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[AndyRandz]

Quick update. Had a quick hour on it today. Checked all earths and cleaned. One wasn't great but again made no difference to running issue. By looks of things next thing I ca do is take the entire loom out and check/rebuild. Really am suspicious of something as daft as a broken wire, the loom has presented other issues that points to this. Wish I'd have just bought a set of carbs and been done with it now!


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[AndyRandz]

Anyone any ideas why I'm getting nothing out of pin 22 EML light.. I've tried different Ecus and still nothing


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[paul080803]

I have a good 20xe loom for sale

[AndyRandz]

I'll take it off your hands. Pm me please mate


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[AndyRandz]

Running at last. Faulty octane switch. Thanks guys


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[totalnova]

Glad you got it sorted in the end.

[AndyRandz]

Thanks bud. Felt like I've been going round in circles all week. Still not 100% right though. She hunts a bit on idle. Slightly too high and doesn't like throttle being applied


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[AndyRandz]

I can rest my foot on the throttle and rpm doesn't really increase. It just sounds like it's misfiring


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[AndyRandz]

Anything real throttle pressure applied it just cuts out


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[AndyRandz]

Job for another day the footballs on!


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[AndyRandz]

Had the octane switch the wrong way round! Idles spot on and revs up a little now. Something still breaking down but I'm not too worried now, soon sort that. Thanks guys


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