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Kamd42p fuel issue

A

amarcafina

Member
My port engine all of a sudden got hard to start. It went from turn the key and crank to having to spin for several second and having to apply the throtle for it to fire up. !!!
I installed a pump fuel Bulb in-line with a check valve, and I can pump it up before starting and the engine will start great.
My question is , Is it 1 or more injectors leaking down to lose fuel pressure , or something else ?? Engine has 900 hrs.
 
its probably air in fuel line. try running the engine directly (submerge pickup and return hose into small canister of diesel), and prime the injection pump manually to eliminate any air. this will eliminate air and fuel line restriction as a problem, or it will confirm one or both. after this free and simple test you can go looking into injectors. if you have RACOR filter, try bypassing it since they are known for air leaks. if it was injectors, you would have black smoke at startup, and also diesel in engine oil.
 
Thanks, are you talking about it sucking air somewhere in the lines?
Wouldn't any air in the system be worked out after running the boat for over 60 hr's on several trips ?

If the boat is not run for 2-3 days I can pump the bulb several times and It will fire right up. If I don't pump it up it will spin for 10- 15 seconds before it fire up.
 
air can come from the lines, from the Racor filter, and from the tank pickup. imagine how long motor would spin before fuel gets to injectors if you let it sit for few weeks? obviously air leak is very minimal, however you are not supposed to have to pump anything in order to fire up the engine, no matter how long it sat, fuel should still be in all fuel lines.
 
I've changed cover and seals on Racor, tighten lines ,bled injectors, looked at all fuel line and still got the same problem, anymore suggestions on where Air might be getting into system . There is some black smoke out the exhaust when It fires up, but not alot.
 
Hi

I have had the same fault with a with a customers kad 42, after bypassing everything including the lift pump we then removed and reconditioned the injection pump and this sorted our fault out, have had the lift pump also drain back before on a tamd 41, to test the lift pump, after running clamp the feed pipe running into the lift pump and return line, if after a few days starts fine then id say you have fuel leaking back to the tank

hope this helps
 
Lift pump was bad ! Thanks , Changed out ,,; 175 bucks and going good now !!! When I got time to look at it I spotted a tiny bit of fuel leaking from the weep hole and knew then it was able to suck air !
 
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