ruthilltn

I have a 99 5.9 and it wouldn't start so I had a spare lift pump and I put it in and I also replaced both fuel filters. When I had my wife turn it to on position the pump would run amount a second and shut off. I ran a wire from batt to lift pump to prime system. I got it to start and ran as normal. I went back about 4 hours later and it wouldn't fire. I did the same as above and it would run then die. My fuel tank shows half full but I put more fuel in it. It seems to run about 20 seconds and dies. I removed the big fuel filter it was half full I filled it up and put it back on and it would do the same thing. I would take the fitting loose at the top filter and there is no fuel. I took the big filter off again filled it up and hot wired the lift pump and loosened the lines to injectors and cranked it until got some fuel coming out. I connected lines back up and I cracked the the fitting at the top filter and had fuel pressure. I cranked it and got it started and drove it around. I have my fingers crossed that it will start in the morning. The real pain is I have someone wanting to buy my motorhome and all this starts. Thanks for any help with this issue. Steve

nickg

likely a air leak in the return side, to know for sure either park nose down hill or leave the fuel cap loose, this keeps the tank vacuum from sucking the fuel back to the tank.
if the truck fires back up after a couple hours, you know you have an air leak

ruthilltn

Where is the return line located? Thanks Steve

nickg

not so much the return line as the o-rings on the connector tubes/ there is a fitting on the back of the head that can be loose/ T fitting near back of head, or faulty fuel cap will all cause hard starts after sitting,
By doing what I said above, it will confirm you have an air leak.
I just re-read your post, just to confirm your Lift pump is working? and do you have a fuel pressure gauge hooked up?

ruthilltn

Went out this morning and it started and ran about 10 seconds I had gas cap loose Looks like fuel pressure at the top filter. I Don't have a pressure gauge but I have the kit to tell if pump is running. It comes on will starting and then goes out when it starts then comes on for 2 seconds and goes out while it is running.I didn't remove any at back of head but I did loosen the injector lines I thought they are all tight if one of them is leaking air wouldn't it be leaking fuel. Thanks Steve