Engine/Transmission (1994 - 1998) lift pump problems

[WDaniels]

A 6 weeks ago I began having starting problems and it finally quit. This was at the same time as GAmes was having his problems. I changed the lift pump, fuel heater and new fuel line from the lift pump to the top of the filter. Now I cannot get it to pick up fuel from the tank. I cannot find any air leaks or fuel leaks. Any ideas to get fuel from the tank to the lift pump? It is getting to cold out to screw with this thing much more. Any Ideas will really be appreciated.

WD

 

[fest3er]

Stick an air nozzle in the fuel filler and stuff a rag around it. (Or make a new cap with a Schraeder valve intalled. ) Pressurize the tank to 5-15 PSI. That should be enough to force some fuel up to the LP. Assuming it hasn't gelled already. Up there in Klondike country, it must be getting down to -30 this time of year.

 

[WDaniels]

Fest,

Not -30 yet but it was zero this morning. It got up to a whopping 14 degrees today at its warmest. That was when I was crawling under the truck putting on the fuel line from the lift pump to the top of the filter housing. That really sucked.

WD

 

[Bob4x4]

Working in the cold sucks... ... ... it was about 80 degrees here today. Have you looked at the returm line from the injection pump back to the tank?The Air pressure in the tank will help you prime it but you will still need to find the root cause of the problem



Bob

 

[Joe G.]

Air pressure in the tank should cause fuel to leak out of any air leak. Do you have a fuel pressure gauge? How long are you cranking it when you try to start? Sometimes when the system is empty of fuel it takes a few cycles of crank for 30 seconds and let it cool for two minutes before it will start. Use a little pedal when you do that.

 

[EKlem]

If you have completely drained the fuel system, I think that you will be surprised how long it takes to get it full of fuel again. The injection pump and the fuel filter each hold a lot of fuel.

I like to use the method of having a friend pressurize the fuel tank while I keep an eye on what is coming out of the bleeder screw and pump the lift pump.

 

[WDaniels]

Joe,

I've cranked it about 4 times at 15 to 25 seconds with long cooling periods. No fuel is getting to the fuel filter and #1 injector and the fuel filter is staying full which with no fuel to #1 injector tells me that no fuel is being pumped from the lift pump. I bought a cheap fuel cap and cleaned out the insides of it and put in a long shafted tire stem so I can pressurize the tank and find any leaks. But it will be below zero tomorrow so you can guess I'm not going outside to screw with it. Its suppose to warm up to 25 above on thursday so I can dick with it then. When I started this I put 6 gallons of fuel from jerry cans so I didn't do all this because someone sucked the fuel out of the tank. Since then I've added another 8 gallons to be really, really sure. Who is the guy for the west coast who keeps and sends out freebees from guys who have made one time tools? Bill Flemming in Montana used to do it. I will donate my pressurizing cap if it works to whom ever does that.



Bob4X4,

Thanks for re-enforcing my opinion of how much the cold sucks and making me envious of you down in the warm weather. Hope Arnie raises your taxes some more. :-laf

WD

 

[Joe G.]

I don't really know what to tell you at this point with the cold interfering with the job.

One thing to think about is the fuel heater. If the fuel heater relay is stuck (smaller of the two on the firewall) it could have burned up the new fuel heater. If the fuel heater sensor is failing it could have done the same thing. There is a grommet on the end of the steel line that fastens to the top of the Fuel heater. If it is bad it will cause an air leak. If the short curved hose from the fuel heater to the lift pump is bad it will cause an air leak. If you have a bad gasket in the fuel heater/pre-filter assembly that will cause an air leak. One test to eliminate these possibilities is to remove the short curved fuel hose and replace it with a longer one to a bucket of fuel. That way there are no "middle men" between the lift pump and the fuel. If it will start and run then something is wrong between the fuel tank and the lift pump. If it still refuses to start then you may have a lift pump or fuel solenoid problem.

If the overflow valve is stuck open then you will never have any fuel pressure regardless of how much fuel the lift pump is moving.

Another thing to remember is that the fuel heater is actually worthless regardless of how cold it gets. There is about a quart of fuel between the lift pump and the injectors. There is no way that fuel heated by the fuel heater can get to the injectors before the batteries run down. Even if the fuel heater is working fine the fuel has to go through a lot of very cold hardware and cold fuel in order to get to the injectors. I doubt that there is any impact on fuel temps at the injectors. If the fuel heater was closer to the injection pump (after the fuel filter) it might be some help.

Messing around with the fuel injectors is a waste of time until you know that there is fuel flow to the injection pump.

It seems to me that you need to find a heated garage to avoid trying to do anything in that kind of cold. It's got to be hard to concentrate.

 

[Bob4x4]

Joe,



Bob4X4,

Thanks for re-enforcing my opinion of how much the cold sucks and making me envious of you down in the warm weather. Hope Arnie raises your taxes some more. :-laf

WD

He is trying to get those taxes up to stay up with the temps #@$%!

 

[WDaniels]

Joe,

The fuel heater and hose plus the small rubber grommet on the line on top all are brand new. Fuel harness would'nt plug in so didn't screw with it as its to cold to mess with it long, so the pumps not burnt up yet. As all the parts except the injector pump are new, I'm stumped. I'll pressurize the tank when it warms up and give it a try. I will say that it took me 4 cycles on my Wabesto heater to get it to draw fuel, then run and provide heat to the block, maybe the lift pump just has not picked up the fuel yet.

WD



Bob4X4,

Didn't mean to hit your sore (tax) thumb with the comment, but I thought it was cute.

WD

 

[WDaniels]

GOT IT! Pressurized the fuel tank but heard an air leak until I realized that it was the pressure equilizing vent for the top of the tank. Is there suppose to be a small hose on that vent? Anywise, I pressurized the tank to about 8 psi and cranked it over, after about 10 seconds, it fired up, missed a couple of times then ran. Ran it for an hour, shut it off for a half an hour and it fired up. If it starts tomorrow, I'm good.

A great big thanks to Joe G. , Fest3er, GAmes, EKlem, Bob4x4 and all the others on the other posts. Thanks!

WD