More problems with a 6.2

[thedrip]

This is a 1985 m1028, 60k miles, but with a civvy IP swapped in.

Truck starts every time, just fine. Dies instantly if I don't keep in the throttle a little bit. if I let it warm up for 10 seconds, it idles fine. It also stalls if I get off the pedal too quick, but that goes away in 3-4 minutes.

Again, it starts everytime, first crank, almost instantly, using the same start procedure I've been using since i got the truck. 6-8 second glowplug burn, half throttle, turn the key.

Other than when I'm not touching the pedal, truck runs fine. Blows the same amount of black smoke as it has ever since I did the fuel screw mod. Driveability is just the same, except for stalling when I get off the pedal while the engine is cold.

Jobs I have recently done to the truck... tranny fluid change, the day before this started happening. Lift pump died & I replaced it, 1 week before this started happening. Fuel filter changed 1 month before this started happening, along with an 1/8th turn of the fuel metering screw. I want to blame the lift pump change, but I have checked all the lines, and they are all tight.

When I drain the bottom of the fuel filter, the first few drops of fuel are foamy, so I know that air is getting in the fuel somewhere.

Any ideas? I'm suspecting a cracked fuel filter base (rectangular style) right now. I've already double checked all the fuel line hose clamps, and the lift pump bolts.

 

[diaric]

a small air leak would explain all your symptoms, until it warms up a bit and sucks air out of the lines.

 

[thedrip]

I think I might have inadvertently solved the problem. It was getting worse and worse, then I parked 'backwards' in my normal spot, and it was fine. I was low enough on fuel that the pickup was sucking some air.. I think. Filled it up, doesnt seem to do it anymore now. Guess 1/8th tank is fill time. I'll see in the morning if all cold symptoms are gone.

 

[thedrip]

Didn't fix it. acted up today. It was a little better, but continued the problem with each cold start. Guess it's time to replace the fuel filter base. Whats the current trendy replacement setup to go with?

 

[kennyw]

I have a spin on filter base from an '83 K20 I can sell you. There is also a secondary filter mounted to the back of the intake manifold. This would allow you to run a quality WIX spin on filter.