truck has been acting up on me a bit lately. '94 idi n/a 275,000 miles. the first time it acted up i heard the engine make a strange noise then parked it to go in a building. came out and it wouldn't start. i towed it to the shop where it started and idles fine twice. started driving the truck again with no problem. after about 10 miles it got parked for a few hours. when i started it to drive home noticed it was acting like the accelerator pedal was sticking. got it home and now it's not starting again. when i tried to start it this morning it started then immediately shut down and won't start. any ideas? i'm thinking fuel pump going out or something with the fuel system. it got a new fuel filter within the last 1000 miles. thanks in advance for any ideas.
the symptoms
- Thread starter tnmtn
- Start date
Titojeep
Registered User
How old is fuel lift pump? If original or old, then when it shuts off, immediately remove the fuel filter to see if it has fuel in it. If it's not full then I would suspect the lift pump. Assuming you have dual tanks, does the problem happen on both tanks? If not, then suspect fuel pick up or something in the tank.
I'm no expert but I thought hard or no start when hot almost certainly indicated an ip problem....
That said, drawing from personal experience, it's normally easiest to start with the cheap stuff. Someone more skilled in diesel-fu will be along shortly.
That said, drawing from personal experience, it's normally easiest to start with the cheap stuff. Someone more skilled in diesel-fu will be along shortly.
Kevin 007
Full-floater
X2 for lift pump, or possible clogged fuel filter.
Both are cheap and will assure peace of mind once done.
Both are cheap and will assure peace of mind once done.
hesutton
The Anti-Anderson
The feeling of the accelerator sticking is air in the fuel (either from a leak or broken fuel pickup in the tanks or a weak lift pump). The start and immediately die is also classic for air intrusion. Will it behave the same way with full tanks or just with tanks that are 1/4 full?
The lift pump can be tested. Take the core out of the schrader valve on the fuel filter head. Hook up a pressure guage to that valve and crank the engine with FSS wire unplugged from the IP. It should be 4-6 psi. For volume, you should get 1/3 of a pint minimum with 10 seconds of cranking.
I'd start looking for wet areas (diesel) a long the fuel system with the return lines/caps as my first suspect. When you have someone crank the engine over and you open the schrader valve, if you get air first, then you certainly have a leak somewhere.
Heath
The lift pump can be tested. Take the core out of the schrader valve on the fuel filter head. Hook up a pressure guage to that valve and crank the engine with FSS wire unplugged from the IP. It should be 4-6 psi. For volume, you should get 1/3 of a pint minimum with 10 seconds of cranking.
I'd start looking for wet areas (diesel) a long the fuel system with the return lines/caps as my first suspect. When you have someone crank the engine over and you open the schrader valve, if you get air first, then you certainly have a leak somewhere.
Heath
you guys are amazing. my knowledge of diesels leans more to larger engines but i was thinking along the same lines as it getting airlocked. i have the batteries charging so i can check on it later this evening. the tanks are about 1/4 full. i may try to bring some diesel home to add and see if it helps. thanks,
godieselgo
Registered User
likely just sucking air in the lines from your broken fuel pickup lines in the tanks.
finally made it home this evening and added 5 gallons of diesel to the aft tank. it wasn't starting on either tank prior to adding diesel. with the 5 gals. added it fired right up on the back tank. thanks for the input.
update, filled both tanks and truck is running smooth when not under load. tried towing around 5000# and it is noticibly down on power. looks like one of the pumps is definitly down a bit. same on both tanks. thanks for the help.
hesutton
The Anti-Anderson
Sounds like the fuel pick ups on the sending units have broken off (common) and you run out of fuel at roughly 1/4 tank. When you have time to tackle this problem. Drop the tanks, pull the senders, and add a length of fuel hose (3/8 diameter if I remember correctly) to the bottom of the pick up. Cut a few "V" in the bottom of the line so it won't suck on the bottom of the tank. That will fix that issue.
Checking the lift pump as posted above may not be a bad idea either.
How old are the injectors and injection pump? If greater than 100K, they are due for replacement.
Heath
Checking the lift pump as posted above may not be a bad idea either.
How old are the injectors and injection pump? If greater than 100K, they are due for replacement.
Heath
