New Fuel Filter - now won't start

H

heathwh

New member
May 28, 2010
7
0
0
I changed my fuel filter about a month ago on my 2003 LB7 (115k miles), after priming and turning it over a couple times it started and drove fine. But then after sitting it would start and then die after 10-15 seconds. I could prime it and then it would start but I had to do this whenever it sat for a while. So I rebuilt the filter head and replaced the lines to and from the filter. This did not resolve the problem and it has gotten progressively harder to start when warm. When cold I can turn the key for a while and it finally starts. When warm it won't start at all.

I just added a Kennedy lift pump and Cat filter head. I primed it, started it and ran it for a while (with pump unplugged) then plugged in the pump and drove another 5 miles. When I got home I turned it off and then tried to start after 5 minutes...no start. The primer pump is hard to depress (it wasn't before) which would seem to indicate that the system is under pressure. I don't see any fuel leaks around the filter head.

I just checked the codes and it has the p1093 code, I haven't got this code before (I didn't have the code when the problem first started). It runs fine, I think it might have just thrown this code after trying to start it for too long.

Any ideas on what else could be causing this problem?

Thanks in advance,

Bill
 
H

heathwh

New member
May 28, 2010
7
0
0
Yes, they are the original injectors. I checked the balance rates in park when the problem started and with the exception of cylinder 7 they were +or- 1 and 7 was +3. Is this within spec?

Thanks

Bill
 
H

heathwh

New member
May 28, 2010
7
0
0
Update

I just checked the rail pressure while cranking and it was about 650 psi until it finally started. After starting up I turned it off and let it sit for a few minutes and now it won't start again (I get one start per day). Is there any sense in applying pressure to the tank while cranking or does the fact that it will start once indicate that the air has been purged from the system?
 
catmenace

catmenace

Member
Jul 31, 2010
255
2
18
May be air leak at fuel filter. Check to ensure rubber gasket is sealing and on properly.
 
dmax02

dmax02

Member
May 30, 2009
105
7
18
Taunton MA
He has a lift pump so if their was any kind of leak it should leak fuel wile the pump is on unless its before his lift pump. I would grab a fuel pressure gauge and put it on the factory bleeder valve on the fuel filter housing. If you have 5+ fuel psi its most likely something on the high pressure side of the system injectors ect...... giving you the problem.
 
H

heathwh

New member
May 28, 2010
7
0
0
dmax02, I don't see any fuel leaks after the lift pump and the 2 lines before the lift pump are brand new since it was just installed this week. It was my assumption that if I added a lift pump then air in the system would be eliminated as a problem, is this a fair assumption? I added a single Kennedy pump so I think I'm at just under 4 psi is that enough to prevent air leakage into the system after the pump? Can I move past looking for air in the system?

My next step for eliminating air as a potential problem was to eliminate the filter head with clear tubing.

It seems like quite a coincidence for final injector failure to occur at the same time I changed my filter.

Thanks,

Bill
 
J

jkholder09

New member
Jan 8, 2012
1,188
0
0
Maryland
heathwh said:
dmax02, I don't see any fuel leaks after the lift pump and the 2 lines before the lift pump are brand new since it was just installed this week. It was my assumption that if I added a lift pump then air in the system would be eliminated as a problem, is this a fair assumption? I added a single Kennedy pump so I think I'm at just under 4 psi is that enough to prevent air leakage into the system after the pump? Can I move past looking for air in the system?

My next step for eliminating air as a potential problem was to eliminate the filter head with clear tubing.

It seems like quite a coincidence for final injector failure to occur at the same time I changed my filter.

Thanks,

Bill
Click to expand...

Was there dirt in filter or did it come apart?
Did you get contaminents in system when changing filter?
Was the filter you took out super old super dirty?
Did you change the filter because truck started running funny?
Did the little bit of air in lines take out injectors on their last leg?

This is all kinda how I would think about it if the truck showed up in my shop.
I am not starting a fight just offering a different perspective, I hope it helps
 
MACKIN

MACKIN

Smell My Finger...
Aug 14, 2006
3,948
1
0
Connecticut
heathwh said:
Yes, they are the original injectors. I checked the balance rates in park when the problem started and with the exception of cylinder 7 they were +or- 1 and 7 was +3. Is this within spec?

Thanks

Bill
Click to expand...

Of what? You really need to check your return rate that will tell the story on the life of your injectors and if that is your reason for a no start.
 
You must log in or register to reply here.
Top Bottom