Truck died again

[Boston]

Sad to say I'm getting used to it. This time I was on the highway and the moment I switched tanks it died. I flipped it back to the other tank but to no avail. Both tanks were full, the forward one of bio-diesel the other of clean filtered motor oil. Thing shut off like a switch. I got it off to the side and towed it home.

Its got 12.85 volts at the batteries, Carter lift pump is working fine, fuel is flowing to the IP, and I checked the shut off solenoid, which seems to be working fine. Although I did not open up the IP and visually inspect the linkages. I also checked the wires going to the IP shut off, also fine. Although I am curious why, if both carry a full 12v why they are two different size spade connectors ?

So I guess the question for today is, what if any other electric components might be interfering with the operation of the IP.

The truck started fine, ran fine, and went off like a switch. No choking or sputtering at all. Seems electrical, but I'm not sure if there's anything but the fuel shut off solenoid that could be the problem. Unless that is something broke inside the ( supposed to be fresh rebuilt ) IP

Any ideas ? cause other than change the IP I'm not sure what might be wrong with it.

Thanks
Dan

 

[icanfixall]

Could be a bad ignition switch. Has the switch been acting funny lately. Best way to test it is to run a hot wire jumper from the positive of a battery and go directly to the large spade connecter on the injection pump. Thats the wire connecter closest to the injection pump gear cover that the pump mounts to. The reason those top wire spade connecters are differant sizes is so we don't mix them up. If you put the advance wire on the fuel shutoff solenoid spade then when the engine warms up the engine will shut off because the sender that supplies power to the advance opens at 120 degrees. That cuts the power to the internal electrical advance circut....

 

[John Deere]

As your applying power to the pump shut-off, listen for it to click.

 

[icanfixall]

Another way to test the ignition switch is turn the key on but engine off section. Then lift the wire off the injection pump that sends power to the shutoff solenoid. If you feel and hear a click as you connect and disconnect this wire that tells you there is power to that solenoid thru the ignition switch...

 

[Hydro-idi]

Boston, did you ever resolve your glowplug issue you had a couple months ago? Just curious

 

[Boston]

I did Hydro, thanks.

Ican, I tried running wires straight from the battery to both spade connectors at the same time. It seems that if both are not connected, neither work. But the advance hasn't been working since I rewired the GPs, which I rewired using information I got off one of the threads. That process couldn't have been simpler, just new wires and connectors. There is a very audible click in the IP when you apply power, but the truck still won't start. Even with the system hot wired. And yes I hot wired it directly to the battery. No go. I'd have suspected a blown fuse, except that the lift pump is working fine. I detached the feed line to the IP and fuel is flowing, at least that far. That and I wired the solenoids directly, but to no avail. I rebuilt the column a while ago, and the switch is new. No problems at all.

I can't help but think its electrical, but I'm not sure what else electrical I can check, both solenoids are getting 12v and both seem to be working just fine. So I think I've got all suggestions covered so far, but no go.

 

[dgr]

Crack the nuts on your injector lines and make sure you have fuel there.

 

[John Deere]

I'm thinking it possible your tank selector valve failed. I had one fail a few years ago, it would allow fuel through the supply side but the return side wouldn't allow fuel back to the tanks. I think a way you can check this theory is to disconnect the return line from the rear left injector olive and see if it will then run.

 

[Boston]

Ok I'll try both suggestions tomorrow. It did cut out within seconds of switching tanks. But it went off like a switch, rather than with any sputtering or coughing, like I'd expect if it was a fuel restriction issue.

 

[Boston]

Ok well there is no fuel in the return line. I checked it at the selector switch and at the first cap on the injector. There is fuel however going to the pump. Its just not getting threw the pump somehow. The solenoids are making that tell tale clicking noise when they are powered and I've hot wired them off a separate switch, so the key switch is not even in the loop at this point.

I'm guessing fuel shut off issue within my brand new IP, again. Even though the fuel shut off solenoids would appear to be working.

 

[John Deere]

I've never had the top off one off these pumps, but I guess its time to take it off and see if something simple screwed up since it appears the shutoff solenoid still operates. The other thing that comes to mind is pull the oil filler neck off and the pump fuel screw cover off the injector pump and verify the pump is rotating. Not that I ever heard of broken pump shafts in these stanadyne pumps, but the old roosa masterpumps of yesteryear had a habit of snapping the pump driver shaft.

 

[Boston]

I had the top off it a while ago when it died on me in Greeley, a lovely 100 mile drive from home ;-) when the first fuel shut off solenoid left me stranded. From what I could see, there's not much to the shut off mechanism. It looked like a overcomplicated bar on a spring that would cover the fuel inlet. The solenoid operates an arm that moves the bar back and forth.

The solenoid makes noise when I apply power, but regardless there is no fuel that seems to be flowing through the pump. New pump by the way. Thing is the fuel shut off didn't look like it should have interfered with the flow of fuel to the return line.

I'm thinking its time to just bite the bullet and spring for a new pump but I think I'll await some additional suggestions before I do so. Someone might have seen this one before and hasn't found the thread yet. Who knows, maybe its just a clog or something. Seems hard to get a clog in there tho, the fuel I use is filtered down to 1 micron. Your suggestion was appreciated tho, seems to have pinned the problem to the fuel pump.

Thing is if the solenoid is working, why isn't fuel flowing, your right it seems odd the shaft would be damaged or broken, and the bar assembly of the shut off although really funky looking, seems like a no brainer, on, off, not much to it. The spring on the bar mechanism seemed barely strong enough to return the bar to its resting position, which I'm assuming is off. So not much chance of it breaking off the arm of the solenoid.

Oh well I'll give it a few days to see what ideas may pop up, but I think your probably right, something in the fuel pump is way wrong.

 

[fsr7]

Did you ever crack the lines at the injectors to check for fuel there? I may have missed that part but that's the next thing I'd check. Is the truck somewhere with tools? I noticed you're in denver, I've got an errand to run in Thornton tomorrow, don't know how available you are. PM if need be.

 

[Boston]

I was out of time this evening but yes, fortunately the truck died only a few blocks from my shop, wood shop, but I keep a set of mechanics tools on hand there for just such occasions. Unfortunately I'm working in Boulder tomorrow, very important job I just can't put off. I'll likely be at the shop thursday milling out some wood. But I'm sure I can handle cracking a line and seeing if there is fuel flow.

Little bird tells me there won't be any fuel flowing, as I try to start it, there is no white smoke, = no fuel.

If I have time tomorrow on my way home, I'll go by the shop and check it out, but I'm not convinced, seems most likely its either a clog somehow, or something failed within the pump.

Not sure how to deal with a clog in these things tho, only thing that could clog it would be a piece of the gasket I made for the fuel screw port. But I used fuel grade gasket. I'll check that as well if I have time.

Thanks for the offer, I'll keep you posted if I get stumped.

Cheers
B

 

[dgr]

Boston,
If I understand this fuel system correctly, the lift pump supplies a surplus of fuel to the injection pump and this gets returned out of the front of the injection pump. This occurs whether or not the solenoid is working. If that assumption of mine is true, if you pulled the return line at the front of the injection pump and cranked it, you should have fuel come out of the nipple. That will tell if the IP is getting fuel. Someone please correct me if I am wrong.