C20let Justing dieing and bogging down help

[Benn]

My engine (c20let) is running like crap. It wants to stall and die and bogs right down when trying to drive it..
Bit of background...

Refitted the engine before PVS. Alt jammed causing the alt ground lead to melt and burn out. That was replaced as was the insides of the alt. Found after that the car would idle off and do this same as it is now when you try and drive/put it under load.
I swapped ECUs as a last try and it fixed the prob straight away. Like night and day running. The ECU light was ok, but i tookit that was from the copied chips. (gave a 69 code which is air temp sensor in the AFM so not a huge worry)

Drove to pv and back then a few days driving, then to the mot. About 400+ miles and it was total and drove fine. Ecu light was on showing the air temp sensor, so i swapped AFM didn't change, so i took it that it was the chips.
Drove to the mot ok even is stop start traffic, picked it up and it started doing it about a mile down the road.

Got a spare std ecu, fitted and tested it, drove around the block ok, but i thought the idle was off, drove to Dan's and it did it bogged down twice on way. Dieing fully on his drive popping the fuse that powers the light too.. which it did 3 more times soon as i tried to drive it. Fitted a chipped ecu and it stopped popping the fuse. Drove back to mine (1mile ish) and it didn't do it at all.... Then started again and now wont stop.

Small video of the clocks/short drive so you can see what i mean.


https://www.youtube.com/watch?v=Yv0ivZhcKAw&feature=youtu.be


I've checked..
Plugs all ok,
Leads all ok,
Dizzy and arm all ok,
Everything is plugged in,
Grounds all connect,
Swapped AFMs still does it,
New CTS,
Tps clicks so i think its ok,
Fuel pump/reply both fine,
Fuel pressure fine.
Wiring looks ok.
3 different ECUs tried. (1 chipped, 2std)
No ECU light on.

I'm at a total lose of what to look at next.....

[Andy]

Gotta be wires.
too coincidental after the fire

[Edd]

^^^^ agree with Andy

you sure nothing else melted ?

engine loom?
car loom?

[brucer]

cant be of help but when I first put my LET in my car I had a hell of a time trying to get it to run properly/starting, was down to a burnt out loom I bought. was all under the plastic cover by the injectors

[Benn]

I've looked along the loom and can't see anything... I haven't taken the injector rail off tho. I'll try that.

Had the fuse box down, all thats ok too.

[Andy]

Just because its visually ok doesn't mean it is

[brucer]

I also had experience with it not starting when a boost pipe had come off, was between the turbo and intercooler and didnt think to check under there. Think i had a fault code for AFM though

[Jeff16v]

Tank Vent Valve wires ok? the loom for those is pretty brittle.

does it rev ok standing rather then driving?
is it before it warms up or after warmed up, lamba problem!
continuity test wires to make sure no breaks?

mine did the same when i first built it, tank vent valve connector wires were damaged.

[Southie]

Any split hoses to the intercooler? Or turbo pipes??

[Benn]

Just because its visually ok doesn't mean it is

Very true. I'll have to buzz the loom out i guess


I also had experience with it not starting when a boost pipe had come off, was between the turbo and intercooler and didnt think to check under there. Think i had a fault code for AFM though

Checked all my hoses, they are all good. I've had that before too... This is very different.


Tank Vent Valve wires ok? the loom for those is pretty brittle.

does it rev ok standing rather then driving?
is it before it warms up or after warmed up, lamba problem!
continuity test wires to make sure no breaks?

mine did the same when i first built it, tank vent valve connector wires were damaged.

FTVV is plugged in but thats all. As it's not piped.
It reves fine, it reverses ok too.. It went you put it under load to pull away..
I've tried it hot and cold thinking the same, but it's like it either way.
Yours wanted to stall while you tried to drive it?

[Jeff16v]

FTVV is plugged in but thats all. As it's not piped.
It reves fine, it reverses ok too.. It went you put it under load to pull away..
I've tried it hot and cold thinking the same, but it's like it either way.
Yours wanted to stall while you tried to drive it?

Mine was one damaged wire under the shielding, do you still have all the original rigid plastic shielding?
it kept trying to stall and I had to compensate with revs. it ended up being that and hose leak.

i've stripped my loom bare a few times to find dried shielding and damaged earths on the rail.

[Benn]

Yea it still in the plastic likd stuff.
To night...

AFM buzzed out,
Tps, air temp, cts all buzzed out and ok.
Coil odd but ok.
Have a crank sensor to try to moz....

[ben doodar]

Im no wiring expert at all benn. but after you burnt out a wire on your alt it's got to be something to do with that. I'd put it on a smaller earth wire burning out inside the loom then possibly burning the plastic outer on some of the other wires chaffing agaisnt them causing the fuse to blow. If that makes any sense lol. Had a similar thing happen to my golf n it played hell up on with the electrics.

Sorry to not shed much light on your problem Benn just throwing some ideas out there.

Maybe worth seeing if you can bell out all the earths on the car with a volt meter.

[Benn]

At the mo i'm gonna try another loom to see if its got a break in it some where that is jumping in or out.

All the grounds have been checked.

[burgo]

I assume by "buzzing" you mean checking continuity?

[Benn]

Yes, plug on sensor to ecu plug.

[burgo]

Thats all very well but thats only really going to tell you if you have a break or poor connection. If you have two wires melted together your continuity can still be fine.

Bogging down as you describe would have me looking at afm, map sensor or tps sensor

[Benn]

AFM ok, tried two.
Unless it's the one in the ECU, lets don't have map sensors.... If it is the ECU one then i've tried 4 ECUs.
TPS works when you move it. And it's more of a switch on a let rather than the xe one when it's gives feed back all the way though.

[Stuart]

It'll be a long boring job, but you want to probe one pin of the connector and then probe ALL the rest in that connector, then move onto the next pin. That way you can check for any shorted wires that shouldnt be shorted.

Or sod it off and put a new harness in regardless.