P38A Rough running

Hi again I have been brought back home off the M4 today as I was just poodling along car lost all power started acting like a misfire have checked on nanocom and I have p1202 short to ground and p0202 injector circuit malfunction but at the same time short term fuel trim on bank 2 is not moving at all it is stuck at 0 have checked the connector with a noid light and it flickers ok double checked with test light for 12 v and ground all ok would a blocked injector cause this problem or is it something else I throw it open to the collective brain in the hope that it is not too expensive a fix thanks in advance don't know if I would still be driving the car if it wasn't for this site and you guys

The wiring to the injectors does get brittle on the V8. Guess one might not be working.

if it is wiring fault then unplug each injector in turn while running (or coughing). The good ones will either stall the engine or make it worse. If it is wiring then definitely not expensive (unless you get LR to sort it). Injectors can't be that expensive.

. . .. BUT. . . I tried this on my misfiring Autobiog. project when I first bought it. Unplugging 6 injectors one at a time each cause worse running. The final two made no difference to the misfire, but the fault was found to be head gasket between two cylinders causing no compression on those two alone.

Hi thanks for getting back where I am now is I have checked the injector wiring all gives off what you expect to see so have stripped it down removed the rail and injectors and tested them on the bench all have good spray pattern next is to try a known good injector in injector 2 cylinder which is where the fault originated and also do head gasket test but I wasn't losing any water from the header tank though but I feel like I may lose this battle

My head gasket wasn't losing water . . . it was blown between two cylinders. Compression test showed zero on these two, but all the previous check indicated injectors or wiring !!

Ah right if that's the case then shouldn't I find it with a compression test then or because it is between the 2 can it be misinterpreted

Compression test should show consistent lower figures on 2 cylinders if HG has blown between the 2 - so between 2 & 4 if my reading of this is correct. In this case you wont loose coolant. Good luck, that bank is a pig to change head gasket.

martynv8 said:

Compression test should show consistent lower figures on 2 cylinders if HG has blown between the 2 - so between 2 & 4 if my reading of this is correct. In this case you wont loose coolant. Good luck, that bank is a pig to change head gasket.

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The only coolant lost that showed with MrGorsky was when he put UV dye in the water and then checked the dipstick with a UV torch after a few days.

Thanks for all the info Bit wet here at the moment so no play today hopefully after work tomorrow will keep updating you on what I find