Backfiring And Running Rough

[Azid Rush]

Hey guys

Recently I put a GCG rebuilt turbo in after mine had shat itself due to fords terrible oil filters. Since the change I took it for a drive to find that under heavy acceleration and pick up it starts massively backfiring and spluttering losing all power. While car was off road doing turbo, I bought a set of NGK plugs and put them in. They were already gapped properly and I was careful not to bump the ends at all so ive eliminated plugs as the problem considering there brand new and gapped properly.

Car is completely stock. On idle and being revved all sounds good and right, just under heavy boost and power it happens. Pretty daunting sound, almost like a car hitting the rev limiter. The coil packs seemed all fine and in good condition when I changed plugs and didnt have any problems before turbo stuffed up. Could the cat have sh*t itself in the changeover, or cat not lined up with dump pipe properly? Any suggestions muchly appreciated

cheers

[IBOO57]

What where the plugs gapped too?

Gap them down to .65 mm and if it still does it get some new coils.

[Redback]

You could check the cat out. Also was the replacement turbo modified in any way or just a rebuild?

Check all boost hoses and vacuum hoses and make sure they're connected well.

[our06t]

Stop being a tight arse azz take into justin for a quick look before you brake something.

[bjc]

What where the plugs gapped too?

Gap them down to .65 mm and if it still does it get some new coils.

What he said

[ali@btamotorsports]

sounds like you can possibly be overboosting get rid of the CAPA tune and get a custom tune,generic tunes dont work on these cars

Edited 13/11/10 09:19 AM by ali@btamotorsports

[our06t]

guys azz has been around here a long time so long ,he's gone from modded back to stock.

just hasn't edited his sig

that's unless you started modding again mate?

Edited 13/11/10 10:28 AM by our06t

[kartman]

Sound like valve float. Is it a BA? Shouldn't need to gap down to .65mm, I have cars running 18psi on .7mm gap and you can experience idle issues and log coil faults with too smaller plug gaps, the ecu feedback expects a certain minimum firing voltage. If you stop really quickly does the car return to a smooth idle straight away? The BA is light on spring pressure, what oil did you use on the turbo refit? I've seen cars with weak springs improve on 5-30 weight oil, don't use a 25-50 oil. If you have a CAPA tune on stock engine then you really want to be around 7 psi as at 6000 rpm this is about all the fuel the injectors can supply, they run lean at the top end. I do my stock engine tunes to boost to 10psi at 4500 and then drop to 7psi by 6000 so maintain mixture.

[Azid Rush]

hey guys

sorry I should have mentioned more about car. Dont pay attention to sig, my car is completely stock again. I did oil changed with Nulon 10-40 I think it was. The car idles beautifully, it runs fine on low boost u can hear turbo spool up, car picks up fine and slows down to a nice idle again, its only when u plant it and it kicks up to high revs

[ratter]

Is the actuator new? if so does it have the same part number as a stock item?

How old are the coils?