[Sinbad666]

I have an early N54 with 74,000 kms


Im running DCi's, JB4 and decats.

Im getting misfires, generally on cylinder 5. I have replaced all the plugs and the coil on cylinder 5. I therefore went back out to do a few runs and reads the codes again.

run 1 - Cylinder 5 misfire

run 2 - cylinder 5 misfire

run 3 - cylinder 5 misfire, cylinder 3 misfire, multiple cylinder misfire

run 4 - cylinder 5 misfire, cylinder 3 misfire, multiple cylinder misfire.

I typically get cylinder 5 misfire if im full power from low revs. But get the 3 codes if I full power say from 4krpm.

Im reluctant to think its an injector as although its typically cylinder 5, I do get misfires on multiples cylinders. I though LPFP would only affect a bank of 3 cylinders. Not sure what the HPFP symptoms are, and same with carbon deposits. I, running map 2 which seems to make the issue worse, but it still misfires on map 0.

What should I do next to identify the problem?

[Mike@N54Tuning.com]

Originally Posted by Sinbad666

I have an early N54 with 74,000 kms


Im running DCi's, JB4 and decats.

Im getting misfires, generally on cylinder 5. I have replaced all the plugs and the coil on cylinder 5. I therefore went back out to do a few runs and reads the codes again.

run 1 - Cylinder 5 misfire

run 2 - cylinder 5 misfire

run 3 - cylinder 5 misfire, cylinder 3 misfire, multiple cylinder misfire

run 4 - cylinder 5 misfire, cylinder 3 misfire, multiple cylinder misfire.

I typically get cylinder 5 misfire if im full power from low revs. But get the 3 codes if I full power say from 4krpm.

Im reluctant to think its an injector as although its typically cylinder 5, I do get misfires on multiples cylinders. I though LPFP would only affect a bank of 3 cylinders. Not sure what the HPFP symptoms are, and same with carbon deposits. I, running map 2 which seems to make the issue worse, but it still misfires on map 0.

What should I do next to identify the problem?

Good chance its the injector unfortunately as its isolated to a single cylinder. The order of diagnosis is usually plugs, coils then injector. You can pull the injector to take a look but it might not be a bad idea to change it.

Mike

[optigrab]

I would have a look at your PCV a non functioning valve can cause misfires on 5

[Sinbad666]

Originally Posted by Mike@N54Tuning.com

Good chance its the injector unfortunately as its isolated to a single cylinder. The order of diagnosis is usually plugs, coils then injector. You can pull the injector to take a look but it might not be a bad idea to change it.

Mike

Hi Mike, Thanks for your advice.

So you think injector 5 although I sometimes get codes 29CF (misfire on cylinder 3) and 29CC (misfire on multiple cylinders)?

[Sinbad666]

Originally Posted by optigrab

I would have a look at your PCV a non functioning valve can cause misfires on 5

How can I test if its working or not?

[mike@x-ph.com]

Start by swapping the injector and see if code follows