Running/starting problem

Just bought a 93 idi 4wd as a plow truck. It has had a decent amount of work done to it recently. When I bought it, it had no noticeable running/starting problems. Just before I picked it up, the fuel filter light came on and the po changed the filter. Now, it is very hard to start, runs rough, idles poorly, stalls and is putting out a lot of bluish smoke. From my research, it looks as if air may be getting into the fuel system. The lift pump has been replaced but have no information on the rest of the system. FWIW, the fuel filter light is still on and it does feel as though it's starving for fuel.

Welcome to the forum. My guess is the lift pump was installed incorrectly and the arm is on top of the cam lobe. It MUST BE on the bottom. Best way to know if this is your issue is remove the pump and see how it was installed. you can "feel" if the arm is on top or the bottom of the cam as the pump comes off the side of the engine. Best idea is to replace the pump and the rubber line that runs to it. they take a beating and do not last forever.

So you're saying if it was installed wrong, replace with new?

Did some diagnostics today. Rubber lines look a bit tired, so ordered a new return line kit. Also, only 1 glow plug checked out, so I need to replace all 8. The batteries were recently replaced but only 600cca ones, so I will upgrade to 850s. Hopefully this will help with starting.

Also, it has a banks cleaner housing. No filter was inside and it's missing the screen on the intake as well.

Usually when the lift pump is installed on top of the cam lobe it ruins the pump.One owner years ago found 3 of the arms broken off in his oil pan when he rebuilt his 6.9. When you remove this lift pump you can feel how the arm is installed. and looking at the wear pattern with verify it too.

Just to point out a couple of things:
1. Easiest way to tell if the transfer pump is running is to simply push in the shraeder valve on the fuel filter while cranking.
If you get fuel spraying out, well, it's working.

2. If the system is primed and sealed, the transfer pump doesn't actually have to be there. The IP will pull fuel and run just fine without it(I know this from experience).
It's harder on the IP, having to pull fuel that far, but it /will/ do it - remember that the IP is actually rated for being gravity fed.

3. If you are continuously getting air out of the schraeder valve, you definitely need to check the transfer pump, lines, and especially the short piece of hose between the frame rail and the transfer pump. This cracks and leaks more than any other piece I've seen.

4. My solution to a /lot/ of different fuel related problems is to install a primer bulb(squeeze bulb) between the transfer pump and the fuel filter. It acts as a check valve preventing air intrusion, it's easy to feel whether you are getting air or fuel, and it makes filling a fuel filter very easy. And they are pretty cheap.

markwemple said:

Did some diagnostics today. Rubber lines look a bit tired, so ordered a new return line kit. Also, only 1 glow plug checked out, so I need to replace all 8. The batteries were recently replaced but only 600cca ones, so I will upgrade to 850s. Hopefully this will help with starting.

Click to expand...

I would replace the GP controller too if I was you!

So, new glow plugs and new 850 cca batteries. Starts easier, still not great. Ran it on the rear tank and it ran better but not perfect. Still stalling.

Beginning to run better on rear tank. Front still poorly. Need to replace rear tank. It's leaking. So I'll need advice on what to replace "while I'm there".

If you're replacing the rear do the F26E tank.

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