Loss of Prime

[BCFAST]

The motor is hard to start now... the "missing cylinder" sound is still there. It seems to lose its prime after sitting for a few hours. This only started after I changed the injectors... (I put in the 370's, took them out and re-installed my 215's). Last night, I took out the #8 and put the #12 back in, in hopes that there was something funny going on there; no luck. Any ideas where to start looking for a leak? There is nothing obvious at the injectors, the pump or the filter area. It may not be leaking fuel out, but is leaking air in!! How do I go about finding this? Thanks, guys!!

 

[Ben Rumson]

Right track

Intuitively, I'd agree that your on the right track, but I'm thinking in another direction that has nothing to do with your injectors or fuel rail...



ANYTHING fuel supply related could be the culprit.



If air's leaking in, wouldn't it spit fuel out under pressure? Not necessarily - especially if it's on your rubber fuel return line - very problematic little bugger that will do exactly as you are describing if it has developed tiny hair line cracks in it. Not large enough yet to allow fuel to escape, but big enough to allow air in if allowed to sit for a period.



Previous TDR issues have addressed.



The line comes off the rear of your pump (past the top of your fuel filter) and runs back towards the fire wall where it connects to and continues on as a metal return line. Getting the old line off and the new one one is pretty much done by feel as it is very hard to see the two connections very well. Only takes a standard screwdriver, 2 hose clamps, and a new 6-8 inch ??? piece of new rubber hose.



Take your old one in to the store with you as a template (diameter, length).



Mine never allowed air to enter, as yours is doing, but it let fuel out. luckily I was close to home and didn't make too long of a drip line leading home.



Whether it's visibly bad or not, you ought to replace this anyway. I bet this will do the trick.



Let me know.



- Bruce

 

[BCFAST]

Thanks for your reply, Bruce. I know the previous owner replaced this hose, but that was 2 years ago so I'll try it! At this point, I'm ready to try anything... maybe the interrior of the hose has deteriorated as well. I just replaced the rubber-coated washers on the banjo bolts on the sides of the pump, and put in a NEW/updated return valve ($70!!!) just to make sure it's all in perfect working order. I found the washers to be rotting!! This may be a nice source of hp gain for some of us, as it's not obvious when looking at it.