P38 rough running and acceleration

Hi all

I have a 1998 4.6 Gems engined P38.

I have just changed both head gaskets due to a blow between two cylinders -all liners were checked and they were where they should be.

The problem I have now is rough running. The engine ticks over if not a little rough, and hesitates and accelerates rough. Its like its missing on one or two cylinders.

I have checked the plugs which are all firing and checked the cylinder numbers along with the stamped in numbers on the coils to ensure they go to the right cylinder.

Can anybody think of anything else which may be causing this?


I bought the car as a non runner so cant say if it was running right before the rebuild. Also, this is not the first rebuild of these engines i've done so i'm confident the build was done correctly.

Thanks in anticipation

Could be a number of things - coil packs, maf sensor, exhaust manifold gasket, cats, hole/leaky exhaust....fuel injection....fuel pump......

Sorted!!

What I did not mention was that the car has a single point lpg system fitted. I have removed the emulators which sit in place of the main wiring into the injectors and now it runs great. These must be faulty or not setup right.

At least I know its been rebuilt correctly!