engine not firing

[lilfuzzer 1]

Any of my rado forum pals could cast some advice

 

just swap an engine with a mate was running great

 

put the front end back on and it no longer fires. It turns over great getting fuel but no spark. Tried new coilpack, leads, crank senor, knock sensor but still no avail

 

going to try the ecu and also after that the cam sensor (this was a brand new one though so thought would be fine)

 

any advice would be much appreciated as we are coming to wits end!!!!

[Tigerfish 10]

Immobiliser?

[lilfuzzer 1]

thought so but it doesnt have one cheers tigerfish

[robrado974 1]

If it was me Chris , i would start at the ECU and work my way to the plugs . also checking any other elecrical plugs . It makes sense that if there is no immobiliser then the problem is somewhere between the above .

[lilfuzzer 1]

Yeah cheers rob wiĺ do

[swiftkid 1]

You had it plugged into vagcom? You checked ECU relay? Main engine plug seated correctly and earths all nice and secure? When you did fusebox did you push the securing pin across?

 

I realise these are all things you have no doubt checked but thought I'd ask anyway

[Dox 23]

What sensors off the old engine haven't you transferred to the new one?

Edited November 11, 2015 by Dox

[fla 9]

As above ecu relay and perhaps crank sensor. Although if the relay were faulty I *think* it closes the injectors too.

[jekel 10]

Hello, this is my car and engine, was gonna post question myself, just bit more info.

 

Have spare 109 relay and fuel pump relay tried both. Every sensor on old engine was new within last few months, new coilpack etc.

Has fired and was sweet as a nut but would'nt hold tickover, now no spark.

Reconned engine now in, mechanically seems perfect, got few hundred miles on it only.

Have spare ecu will be trying on weekend.

2nd on my list of suspects would be crankshaft sensor lead (the loom side plug) I had to put a new plug on it while back soldering wires onto original lead, as wires at plug end totally frayed, any way of checking with a meter rather than stripping that lead back totally to check which would be a pig of job due to where it's joined (from outside looks ok, insulation not broken, heatshrinked and wrapped, but VR6 engine and box was a tight fit getting in, especially on the side that lead goes, maybe we nipped it.

Any other possibilites we ain't thought off?

(We've also tried a spare coilpack, leads, but both leads and coilpack on mine like 2 months old anyway).

 

Cheers.

 

Any electronics wizzes that are passing Chris's in Durham feel free to drop in, all info. greatly received.

[jekel 10]

If it was me Chris , i would start at the ECU and work my way to the plugs . also checking any other elecrical plugs . It makes sense that if there is no immobiliser then the problem is somewhere between the above .

 

Hello, this is my car and engine, my thinking is basically as above, I'll stick my spare ecu in on weekend, but if not that how do we check from there to plugs. Coilpack is 2 months old, as are leads and plugs but already tried spares for both anyway. Have spare 109 relay and already tried that.

Second on my list would be crank sensor plug-lead on loom side, I put a new plug on it while back, wires frayed at plug end, looks fine, but maybe we nipped lead putting engine in, was damn close on that side. Anyway of checking without cutting out insulation and checking join (would be pig due to where joined, heatshrinked and wrapped).

Anyone near Durham got Vagcom?

Engine has fired, ran sweetly but would'nt hold idle, now no spark on any leads.

 

 

Cheers

[jekel 10]

P.S. old engine and new both coilpack VR6's, all sensors from old engine few months old at most so now on new one. Are any of the sensors different on years of coilpack VR6's, all fitted fine and looked identical. Old engine a 94 VR6 OBD1 (Think all Corrado's OBD1?) new engine don't know but is recon engine and sounded sweet as a nut when did fire, what did see cams, chains are clearly brand new.

ECU and my spare are CP from memory for the 94, no immobiliser, standard one in at mo, remapped one is spare, both ran perfect on old engine within last few weeks.

[swiftkid 1]

Cp is an immobiliser ecu, but still it would let it fire up then cut out.

 

Doh, fla is right but if you've checked anyway that rules that out. You could unplug ecu plug and test for continuity to main plug then onwards for there

[Roger Chatfield 0]

I'm not sure what has happened here, are you saying you fitted the new engine and had it running, then when you fitted the front end the engine will now not start?

 

Rog.

[jekel 10]

I'm not sure what has happened here, are you saying you fitted the new engine and had it running, then when you fitted the front end the engine will now not start?

 

Rog.

 

We fitted new engine and got it fired up, after some considerable effort, ran for few seconds (radiator) not connected, then hooked up radiaitor etc., put front end on, ran again for a while, running really sweet but would'nt hold idle, now won't start at all. Was very weak period spark when checked leads, now none at all.

Every time it did start was a real effort.

Seems like had very weak intermittent spark now none at all, something spark related was "struggling" now gave uop the ghost seems to me. Putting front end on, coincidental

[jekel 10]

Couple more things, looking round another VR6 I have here the blue exciter wire from alt, one that connects to 1 pin plug at front, 1 blue wire in 2 out, the second wire on this VR6 goes into loom by look of it, on mine it goes nowhere, looks like been cut after few inches, not ssure we did that mind, could this cause the prob? What's that wire do?

2nd and this is weird, on my non starter when you put lights on and flash main beam with ignition on the fuel pump primes for a second, like when you first turn ignition on!!! This mean anything to anyone? Had all lights disconnected, obvious when front off, most were factory plugs connections etc. think he had to cut a couple.

 

Cheers

[swiftkid 1]

I can't get access to wiring diagrams at work but I believe you have the blue wire for battery warning light and the other is tacho signal on some cars (W signal)? Not sure on that I'm afraid.

 

As for the lights, I would say thats too much of a coincidence that engine fired up before front end was built and now fuel pump is priming with lights. Have you checked that you havn't trapped an earth as you were putting the front end on? Usual place is front of chassis legs where slam panel bolts on. Have you tried unplugging all the lights and trying to fire up the engine? I realise its a bit of a pain but maybe take front end back off again to eliminate the variable of the front end causing issues.

[Roger Chatfield 0]

If you mean this wire.

 

It does nothing, had the same problem with mine when I removed my front end, asked the forum and was told it's not needed.

 

Rog.

[jekel 10]

If you mean this wire.

 

It does nothing, had the same problem with mine when I removed my front end, asked the forum and was told it's not needed.

 

Rog.

 

Cheers yeah that's the one, that's saved a bit of searching and head scratching. In fact I tried unplugging that blue wire plug altogether on the green VR6 I've got here and the car still started and ran which surprised me

[jekel 10]

Now sorted, running sweetly, thanks for all replies. Dodgy crank sensor to harness lead, now fixed (think probs. trapped it putting engine in, and crank sensor not seated fully/properly.

When tried to move it was stalling, turns out the starter motor live feed was touching gear selctor when fully in reverse or first which I'm guessing explained the strange electrical thing, fuel pump priming when flashed main beam thing.

Engine, clutch box now all as new, whoohoo!

[robrado974 1]

Glad you got it sorted .