QuestionHi Ray!
My 1995 Volvo 850 has developed a problem. Intermittently it blows the fuel pump fuse. It happens periodically, but not always or not always right away. Noticed that it doesn't happen when driving on a highway, but rather on streets when stopping at the intersections. Typical pattern is that when I brake, the engine drops the speed, and normally it goes into idling mode, but sometimes it feels like the engine drops too slow for idling, tries to pull it up, jerks once or twice and then stops with all indicators lights on.
At this time that fuse is blown and I cannot restart the car without replacing it.
Sometimes it would pull itself out into normal idling.
Once or twice happened while idling at the red light for too long - was perfectly fine at first, but then the engine seemed to start slowing and stuttering and stopped. Fuse blown.
Noticed when it starts stuttering, and if at that time I go into gear and start driving - it goes back to normal.
Wasn't able to determine if it does it more when already driving for a while, or when I start cold. Had it both ways.
I'm not too skilled, but wouldn't shy away from basic and simple procedures on a car. Anything I can look into myself before taking it for a service?
What would be the primary suspicion for the reason?
I find it hard to blame the fuel pump itself, reasoning that it always works fine when I give it a load.
I also tried to check the fuel pump relay - didn't replace it completely, but tested the circuitry (followed hints from a Volvo forum).
That's what I know is sitting on that fuse's circuit,
but there might be more components and more action is going on than that! Any advice or suggestion is greatly appreciated.
Thanks a lot!
AnswerAbacus,
The pump is either drawing too many amps or the wire is shorting out somewhere. No test for a shorted wire just begin tracing. Put an amp meter on the pump, use the min/max recording the amp draw to see if it is drawing too many amps. If in doubt replace the pump.
