P38A Backfires back.

Posted on here a while back with the car backfire with a popping and tinny sound in the exhaust. Last time couldn't find the cause so disconnected the injector and ran it on 7 cylinders fuel consumption was horrific . Bit the bullet and got another cylinder head and fitted it this weekend. Rebuilt engine and f++@ me it is still happening. Son following me home reported no **** out of the exhaust except when it pops. So what is happening it has to go for mot soon and I think it will fail with this problem. What are the thoughts regarding redex and ragging it down the motorway.
Surely valve problems can't be the cause unless I am cursed.
It is a 1998 4 litre petrol gems engine. If somebody is near and can listen to it that would be great.

Wow that's a byatch! Are your plug leads right? Coil packs working ok. Maf sensor working well( swap for a good un) fuel pressure, injectors ok.
Some clever diagnostic work required here.
Jb

Blimey not much action on your thread duncs!
Jb

Blocked cat/silencer?

Worn cam?

Coil pack or spark plug breakdown? Sounds electrical if its missing / overfuelling into the exhaust

JimS said:

Coil pack or spark plug breakdown? Sounds electrical if its missing / overfuelling into the exhaust

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Brand new plug and replacement injector have ordered a coil pack have tried swopping plug leads but problem didn't move so assume leads in order. Hopefully new pack will sort it.

myfirstl322 said:

Blocked cat/silencer?

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Same amount of "smoke" from both exhausts

Compression check essential. On all eight. Hot engine.