'86 951


I just changed my fuel pump, cause i had a really loud electrical failing pump noises, so i swapped it out today with a new pump, and was very happy to find it didn't fix anything, still making the same noise.....


So now I have a new fuel filter, new pump...those can be ruled out

what should i check next? what else in the fuel delivery system would cause thepump to whine...im thinking maybe it is not getting enough fuel to it...cloggage at the tank maybe????

any help appreciated

thanks
mike

 

I 'think' when the FPR is failing it can cause the fuel pump to make more noise. The excess fuel is just returned to the tank and the pump keeps humming rather than maintaining a static pressure. This happens frequently on 90's Z cars and Infiniti's when the pressure controller fails the fuel pump goes into full speed ahead and sounds awful.

 

Also check the check valve right at the fuel pump. Sometimes if its stuck it could create extra pressure for the pump similar to a blocked artery in the body.

 

Yes, my pump groaned quite loadly when my FPR went. The bad FPR sent the fuel pressurre way high and I guess that was hard for the pump to work against. New FPR absolutely solved this one for me. Do you have any hot-start problems (I used to)? That's another indicator (fuel pressure leaks down too fast).