fuel pump not priming?

[smoke81]

truck starts every morning no problem or when its been sittin for a while..but when it is warm, if it doesnt fire right away it will just crank endlessly. but starts right up with ether.this happened a few months back but one day just started firing everytime till the problem came back again. i changed the gas cap and relay but nothins changed.i did notice that if it wont start and u depress the pressure release valve a burst of air and atrickle of fuel leaks out and it will start right up.

 

[jhammel85]

Which valve are you talking about? On the fuel rail?

If so, it sounds like it has air in it..which is definitely a 1st for me!

I would try checking the fuel pressure with a gauge. If you are a "do it yourselver" it'd be worth the 40 bucks from advance! I use mine alot for alot of different cars.

If you find that its holding pressure when you prime the pump with the key, then all is well and I would look else ware. However, if its not high enough, It could be a pump issue.
Lastly, if it doesn't hold pressure or you smell gas when you pull the back vac line off of the regulator, the fuel pressure regulator is bad.

 

[modelageek]

I agree with the others.it sounds like a problem with air in the fuel line. I would check the fuel pressure regulator on the fuel rail. there should not be fuel in the vacuum line. change out the fuel filter and add some TECHRON TO THE TANK. This has been known to crorrect sticking check valve etc. I am not sure where the check valve in your truck is. it might be in the fpr or in the fuel pump in the tank.

 

[smoke81]

thanks for the input... after more investigation i learned what an ECC relay was. turns out after all the head scratching and and fuel system testing it was the ECC relay. my initial thought was the fuel pump relay was the problem when i changed that and no change i moved on. in my head ECC said Emission Control C...? now i know better to assume i know what everything means...a little research goes a long way