Another week, another DB9 problem.....advice needed.

[paulrog1]

Hi,

I drove the car this morning from cold, as soon as I started it up it sounded quite lumpy, like a misfire, no warnings or engine light on, very strange.

I drove the car for 300 yards, then parked up to do abit of shopping for 10 minutes, I started her back up and it drove fine.

I checked for any fault codes using my OBDII reader and I got 1 code - P0202 which is Primary PCM - "Injector circuit/open, Cylinder 2" Or Secondary PCM - Injector circuit/open, Cylinder 8,

I had the Ignition coils & sparkplugs replaced a month ago with no problems.

So do I need to replace a fuel injector? if so how do I know if the faulty one is cylinder no2 or 8, plus which cylinders are 2 & 8(when looking at the engine) ??? Or is the error code something else??

Any other helpful advice would be great!!

Thanks.

Edited by paulrog1 on Thursday 6th October 19:01

Edited by paulrog1 on Thursday 6th October 19:09

[BamfordMike]

Care needs to be taken when using generic fault code reader on V12 because you can only read primary ECU (drivers side of engine) and you could have faults on / as well on the secondary ECU (passenger side of engine) which you will be blind of knowing when using anything other than factory diag tool.

However, cylinder 2 is second cylinder back from the front of engine on drivers side.

The code means the ECU has detected an electrical disconnect, it's very unlikely the problem is injector, more like a connection / harness issue because you have recently disturbed the system - could be a backed out pin in plug even though injector is connected.
If your misfire is bad and you have primary cats still fitted, be real careful to not drive far or Rev engine high!

[DB9VolanteDriver]

Sounds like an intermittent open circuit, which therefore would most likely be a wire break or loose contact, rather than the injector itself. Once you identify the correct cylinder (can't help you there), maybe you can access the relevant wires and wiggle them about while the car is running to see ifyou can replicate the stumble/fault code.

[paulrog1]

Thanks very much for the info,

I will look at the wires tomorrow,

Can anyone tell me which one is cylinder no8 ??

Thanks again.

Paul.

[BamfordMike]

As I said - you don't really know which side of the engine you have a problem with by using the generic scanner

2 and 8 are both second cylinders back from front of engine on each bank.

[paulrog1]

OK, found a bad wire at Cylinder no2 connector to the fuel injector, so I soldered it together and used some heat shrink sleeve.

I'm going to try to find a new connector as I think that will be a proper fix.

Thanks very much to Mike and DB9Volantedriver for your help.

Dare I say it..... the car is trouble free at the moment !!!