The Return of the Fuel Gremlins

[Begle1]

Not again...

Drove to Jack-in-the-Box this morning; along the way it seemed to power out ever so slightly on the way. Didn't think much of it at the time; figured it was just the tranny loosing another gear or something .

Parked it, came out of Jack-in-the-Box, no start. Cranked, but no start.

So I cracked the injectors, and they all seemed to have fuel almost immediately. Bled them and it still didn't want to start.

Checked voltage at the solenoid, and that was good.

So I cranked it over 10-15 times in desperation and it started, ran rough for 20 seconds, then cleared out. Never had to crank more than 2-3 times before, even after priming it. After it started once it starts on the first crank again.


The thing runs fine until I sustain it for over 20 seconds at 2400+ RPM. Then it slowly starts to loose power; you can give it extra fuel for a little while to sustain RPM, and then you have your foot to the floor and the RPM gradually drops farther and farther. If I put it in neutral than it sometimes drops down to 350-450 RPM and manages to "idle" really rough there, and I can clear it up with some pedal. If I leave it in gear it would probably stall at that point, like it used to do.

It seems an awful like my last problems. I think I was ingesting air the last time, I just had to prime it to start again. I don't know about now... Feels like the same thing, only it's a lot more repeatable.

Thing ran fine in the two-three weeks since I ran new fuel line.

Is there a seal in the injection pump that can be sucking air?

What could cause it to not want to start after driving it for 10 minutes to Jack-in-the-Box? Classic sign of dead injection pump, right?

[flashgordon]

I don't thing so get some clear plastic line and put a loop of it between the tanke line(were it hook to you lift pump) and the lift pump and then a 2nt on form lift pump to VE pump.


If you make the first one long enough you and wrought it out of the corner of the hood and over you wiper arm, and been back to the pump.

This way you can see the air rushing thru the hose while the long skinny peddles mashed, and under a load.

It's pulling air from some were when the volume is HIGH.

Could be the pump,............But i would try this first!!!


Flash.

[Begle1]

That's an idea.

I've replaced the line from the tank to the lift pump, and I pressure tested the system in front of the fuel pump. Didn't see any leaks there.

Only part of the system I don't have leak tested is the sender in the tank. It's just a single "L"-shaped piece of metal tubing. I pulled it out and looked at it, it seemed fine; don't know how it can go wrong. But if it does have an invisible hole sucking air, the truck might have been good for the past two weeks because I had a full tank of fuel, and it just now got to below the hole in the sender. I wouldn't mind putting a larger diameter line in it anyways, but there's 80 pounds of sloshy in the tank now.

It seems repeatable enough now that I'm going to drive it around the block tomorrow until it stalls and see if I have air in the injectors...

[Begle1]

Well, now it's really repeatable...

I had to prime it to get it started this morning, even though it was idling fine when I shut if off last.

Got it started, it was running fine. Took it around the block once, taking the engine up to 2400 RPM 3 times for a total of 30 seconds, and by the time I got back to my house it was loping down at 450 RPM. Got it into the driveway, let it stall itself.

I primed it again, and now it lopes at idle. Turned it off, and no start. So now I gotta prime it every time I start it, and it's not drivable.

Good news is that now I can start plumbing in vinyl hose and check for bubbles without driving it anywhere. It's so convenient.

So I take it that nobody has ever had these symptoms?

Think it'd be smart to run a line from a fuel tank sitting on the radiator straight into the injection pump inlet and see if it'll clear up the idle?

[Begle1]

I gravity fed the pump, started it up. Made no difference; ran it for a minute, really sloppy idle, very rough under high(er) RPM.

I guess I'm in the market for a new IP now. Anybody know of a P-pump conversion kit for sale?