Archived 98 12V won't start

[btbuchanan]

Turns over well, but acts as if it has no fuel. Has been running well. Potential change equals cause... have burned about half a tank of fuel with 'Sea Foam' in it. Have not used fuel treatment before. Seemed to be running better with this fuel additive. Checked/replaced fuel filter. Had 8K on it and it was OK, but changed it anyway. Fuel shut-off solenoid is operating. No obvious cracks/leaks in the fuel supply. Have the screen/gasket kit on order for the fuel preheater. Won't be here till Tue. Other ideas in the mean time?

175,000 miles, NV 4500.

Thanks,



Bruce Buchanan

Appleton, WI

 

[Missouri Mule]

Are you sure you have fuel in the tank? The fuel senders are known to act up.



If you are sure fuel is in tank. When you primed fuel filter did you crack open the the banjo bolt on the supply side of filter?



If so crack open the banjo bolt on the injection pump if you have fuel there crack open a injector or two.



I would turn key to the on/run position and then push the rod to the fuel shut off solenoid up. The rod should stay up. Try to start.



Usually on the pre-filter rhe screen just needs to be cleaned and gasket is re-usable.

 

[btbuchanan]

Bill, the tank is half full. The truck start problem began Friday morning and I had not changed anything. I changed the fuel filter as a precautionary measure after the problem started. Will push the rod up and see if it holds with the key in the on position. Thanks, Bruce Buchanan

 

[btbuchanan]

Bill, The fuel solenoid is operating properly. Stays up in the on position. Bleed procedure did not help. Still no start.

Bruce

 

[GAmes]

When you opened the bolt on the supply side of the filter and manually pumped the pump did you get solid fuel right away or bubbles? If you got bubbles you are drawing air from somewhere, most likely the rubber hose that comes from the tank to the engine or the L shaped hose between the prefilter and the pump. If you have never changed either one they would be my first suspect.



If you do a search there are a lot of threads on this subject.

 

[Joe G.]

Sounds like a fuel heater failure to me. That's easy to fix. There are other possibilities. Email me at -- email address removed -- for my 12 valve fuel supply system write up, how it works and how to fix it.

 

[GAmes]

Yup, forgot about the heater. Took mine off long ago, out of sight, out of mind:-laf

 

[btbuchanan]

Thanks gentlemen.



Quick update. Have found that lift pump pressure is down to 5 psig. Having to bleed air every morning to get it started. Lots of air. Ran clear pvc tube from tank to lift pump inlet and the 5 psig number is still the same... bypassing the entire suction supply to the pump. I think that eliminates the air problem in the fuel supply up to the hose between the fuel preheater and the pump. Have it on order as it was not in inventory at the dealership. Thanks for all your help. Will update once the hose comes in. Bruce

 

[btbuchanan]

When you opened the bolt on the supply side of the filter and manually pumped the pump did you get solid fuel right away or bubbles? If you got bubbles you are drawing air from somewhere, most likely the rubber hose that comes from the tank to the engine or the L shaped hose between the prefilter and the pump. If you have never changed either one they would be my first suspect.



If you do a search there are a lot of threads on this subject.

Thanks, will check it out... Bruce

 

[Joe G.]

If the fuel heater is still in place, remove it and see what happens.

 

[Sticks]

I must apologize as well, it has been so long since I have worked on a 12v Dodge, that I completely spaced the fuel heater assembly as well.

A fast and easy way to check the condition is to pressurize the fuel tank to approx 15psi and watch the heater assembly for leaks. Typically they start leaking around the wire harness connection (which is also typically melted/burned, thus requiring replacement of the wiring as well).

Sound like you probably have the problem isolated. Good luck.

 

[btbuchanan]

Final update... sorry about the delay. Found one bad hose that had several air leaks on the suction side. The lift pump piston spring did not fit well into the piston and has been applying a torque to the piston. Top of skirt on one side and base of skirt on the other side were worn. Replaced lift pump and bad hose. Now have normal pressures and truck starts and runs better than it has in a long time. No more acceleration lag at low RPM. All is now well in Dodgeville. Thanks for all your help.

Bruce Buchanan

 

[HerbW]

I had the same trouble with my 98 truck and hoses. It was a real problem with that year. The best hose which I used, is the marine grade type. I've never seen them go leaky. If you look at it, it has a clear inner liner tubing inside it. Maybe made out of neoprene? You get it at boat dealerships or Ebay. Glad your rig is going again. Herb