My friend has a Vectra 2litre 16valve Turbo Diesel R Reg. It has recently had a new (over £1000) diesel pump fitted to cure a non starting engine. The problem is that it missfires when cold and a little bit when warmed up. The engine management light comes on, the only way to extinguish it is by turning off the ignition and restarting the car. A friendly garage has so far tried new :- non returns on diesel lines Vac pump Eng management temp sensor Air flow regulator sensor.
Please help
If the engine management light is coming on, then the first thing to find out is the fault codes.
But from what you've said, I'd be inclined to suspect a mechanical fault. Does the vehicle go into limp home mode (ECU cuts power, and limits revs to
3.5k)? Does the vehicle start fine from cold apart from the misfire, or does it cut out? If it cuts out, it could be the injector seals leaking, allowing air to be drawn back into the system, which could cause erratic pump timing, which would trigger an injection pump timing fault code.Was the fuel pump replaced because of a mechanical fault, or an electronic fault? If it was replaced for a mechanical fault, it's most likely the pump had broken up internally, which could mean that one or more of the fuel injectors could have some debris sticking it, which would give the symptoms. Or it could be that an injector has failed for no apparent reason, and as this engine alters the fuel quantity for each individual injector, it may be detecting that the injector has reached the maximum allowable adjustment and is signalling a fault.
The only real way to find the fault, is to start by looking at the fault codes. As for the parts that have been replaced, with the exception of the fuel return pipes, none of them would cause a misfire.
Thanks for your help, sounds interesting especially the blocked injector bit.
Have something to add? Share your thoughts — no account required.
Ask the community — no account required