ran 2 different pumps on same truck,identical set-up. one pump seems weak,makes about 4 lbs lees boost, both are non i/c pumps. the weak one had a bad ksb,on all the time. ive never been deeper in a pump than gov. spring install,would a part wear due to higher case pressure of ksb not working? what wears inside of pump when they fail? pump runs good,smooth,starts good,just weak on fuel. help appreciated

 

Could just be a difference in how they are tuned maybe.

 

both tuned the same, fuel screw turned to almost runaway,same afc set-up. looking for info on internal pump wear parts.

 

I am also curious about pumps internally. I got some water in my fuel was passing right through the filter and didn't know it until the engine started missing(would have a dead hole every 5-10 seconds of running). Now I seem to be down on power and would like to know from the VE gurus if they can be tested, what would most likely wear out/be damaged from contaminated fuel, etc and can they be fixed.

 

A pump shop can put it on the bench and test the flow rate.

The head & rotor assembly and the cam plate & rollers are the most vulnerable to dirt or poor lubrication.