Hi all, After a track day I noticed the car idled unsteady when hot. When pushing on subsequently it had a power surge and then, then a few seconds later went into limp mode. This felt like running on 3 cylinders however only periodically, with the limitation on power. A restart temporarily fixed the issue. Took it for a full service and replaced the spark plugs and car had again had wandering idle when warm, and a delay in power delivery. I reved it in 3rd again 4k revs and it went into limp mode again. Plugged into diagnostics at the garage today, it stated ECU name missing as one code that would be unusual. A reset of the ecu didn't fix the issue (happened straight away on my drive) so returned it to my local garage and they are about to start the strip and test/replace process - is there anything that jumps out to the specialists on here? Any help will be much appreciated. I have heard about an injector ECU grounding issue which could tie in with the electronics and fuel control issue? Could it be this. To save cash and stripping too far I will see if it's the coil packs first and then take it from there, though I had a coil pack fail on 250 and it was more drivable with no limp mode.. so not obviously the same? Any help or other ideas really appreciated
Spent over a grand on trying to fix this. Key symptom is power surges (a request for full throttle), and then the car reacting and going into limp mode - only when pushed. Limp mode has a 3cylinder feel.if driven steady it doesn't happen. There is a tell something isn't right however and that is an unsteady idle (really bad initially before replacing spark and ignition coils). This happens if left for more than 20 minutes and restarted, but not after cold where idle is smooth as. When checked at ktec I recreated the problem, and when in limp mode they found injector 3 wasn't firing (no change when removed/stopped). Does limp mode normally run on 3 cylinders!? Does it protect the issue area? Or should it be working with 4 cyclinders? What does this tell us? We've done the coil packs, oil servicing and spark plugs and we're no closer to solving the problem. What controls the injectors? And if it was just 1 injector how come a full throttle request is registered and I get a power surge. Sounds like a control issue for the fuel system. So you have any advice/ thoughts?
Limp mode usually cuts power to protect the engine, but it should still run on 3 cylinders. It could be a wiring, ECU, or fuel control issue. You might want to check fuel pressure or have the ECU checked.
The ignition coils run in pairs, so if a coil goes open circuit it will drop 2 cylinders. I have just sorted a mates out, it was an injector that had failed, easy test, for that is to disconnect one at a time and each one should have an effect on the idle. If you are replacing coils, then use Beru ones, plugs need to be genuine NGK not Ebay ones, been there
