1999 4.3GI - low/high pressure fuel pump symptoms

[Radon17]

Hi, was wondering what the signs are when your low or high pressure fuel pumps are going out. The obvious is the engine won't run, but from other's experience what are some of the initial signs? And how many hours/years do you get out of these little pumps? - Thanks!

 

[dypcdiver]

Re: 1999 4.3GI - low/high pressure fuel pump symptoms

Whining and getting hot are clues. As for hours, mine have done 550hr without problem. I change the filter at approx every 50hrs but I also have a large pre-filter/water separator in the supply line. I don't think that the vapour tank on the setup that has a remote LP pump has the paint problems that the combined HP and LP vapour tank has.

 

[JoLin]

Re: 1999 4.3GI - low/high pressure fuel pump symptoms

Yes, whining and running hot are common indicators, and either should be a red flag. They can whine if air is entering the system, a filter is clogged or the pump is failing... and sometimes they're just 'whiney'. My 1999 whined for the entire 2 years I owned the boat and never gave me a problem.

All that said, sometimes they just quit. Happened to one of my low pressure pumps last year. Sudden RPM surge on the port engine, then nada. It IS possible, however, that the pump had been running hot without my being aware of it...

 

[Radon17]

Re: 1999 4.3GI - low/high pressure fuel pump symptoms

Thanks for the replies! Great info.

 

[Technologic80]

Re: 1999 4.3GI - low/high pressure fuel pump symptoms

Mine hard starts when cold, when the high pressure pumps act up.

When my low pressure bit the dust, the engine wouldnt fire at all. Just crank/crank/crank. Funny - it still made its normal hum though, but just produced no pressure.

When my pumps whine or if I have a cold-start problem, I simply tap the fuel pump with something hard (handle of a screwdriver) while somebody cranks the engine, starts right up after I rap on it and doesnt act up until next time. For this reason, I carry two brand new fuel pumps - 1 low pressure, and 1 high - on board at all times!

(Owner of twin 1997 4.3Gi's)

 

[Radon17]

Re: 1999 4.3GI - low/high pressure fuel pump symptoms

Mine hard starts when cold, when the high pressure pumps act up.

When my low pressure bit the dust, the engine wouldnt fire at all. Just crank/crank/crank. Funny - it still made its normal hum though, but just produced no pressure.

When my pumps whine or if I have a cold-start problem, I simply tap the fuel pump with something hard (handle of a screwdriver) while somebody cranks the engine, starts right up after I rap on it and doesnt act up until next time. For this reason, I carry two brand new fuel pumps - 1 low pressure, and 1 high - on board at all times!

(Owner of twin 1997 4.3Gi's)

I just bought two new pumps and keep them on board ;-) Thanks!