Did you put a in tank pump in your truck because they don't come from the factory that way.

You can have 25 PSI and also still have air bubbles in your fuel. Have you ever cracked open your bleeder after it has sat for a long period of time and before you have tried to start it and manually pump the LP and watch to see if air bubbles come out before fuel does?

If you don't get air bubbles then pinch the return line with some vicegrips and see if it fires right up, if it does then hurry and take the vicegrips off and replace your overflow valve on the backside or the IP.

 

Hows your shut off solenoid?

 

That would be my guess. Solenoid needs to be removed, toss the deteriorated boot, clean, dry lube and reinstall.

 

Interesting suggestions, thanks. I'd not have considered the solenoid & I think the boot's gone from biodiesel softening, but I might be thinking of another machine. (are those boots really just for decoration? I once searched in vain for replacements...I get the notion of dry lube, but nothing on my engine's gonna stay 'dry' for long, I am sorry to say. A silicone boot would be nice.)

Promise to get on this when it's not 2:27AM.

 

Biodiesel softening?:confused013: WTH is that? New boots available here if you think it is necessary. LarryBs.com Dodge

 

Biodiesel has amazing solvent properties - softens "gas rated" hose other than stuff that's got...what is it...USCG A-1 rating, I think it is. It doesn't happen right away, so if you convert to biodiesel, you just need to plan on doing it before long. Wait TOO long, and they get kinda tarry on the surface (nasty to handle) and eventually will start leaking at a pinch-point (band clamp). (Yeah, ask me how I know...)

I recently found that there had been enough misting or weeping from that one-time biodiesel leak to soak my transmission vac lines on the top of the tail - which, a few years later, let one kink under vacuum - which kept me from getting into 4WD...

 

I've heard bio being blamed for a lot of things, but that is a first. Diesel deteriorates gas only rated hose, that isn't news. So do you regularly splash bio on the solenoid?

 

I was just wondering how many miles or years does it take for diesel to deteriorate gas only hose.

 

If you want to test if it's your solenoid, next time it does not start keep the key in the run position and push up on the solenoid and see if it goes up any more. If it does then it didn't get pulled up like it was supposed to and you need to clean it, or replace something.

 

Yeah, I like that idea - simple diagnostic, as long as I can get myself out of the mode of "nah, I was going to GO somewhere...gotta get this thing started, not take my seatbelt OFF now...just crank it again..." And actually it's been so long since I laid eyes on the solenoid, I can't remember for sure where it's positioned around the IP. (Don't worry, I'll find it again...)

 

ya, I know, but I have nothing better to do, or that I want to do anyway.

Besides last week I took the camera out and took A LOT of random pictures, because a pictures worth a thousand words, and frankly I'm not that good of a typer.

 

Thanks...how I yearn for those black depths of mystery, the cramping, the sizing of wrenches by feel...I keep meaning to install hinges in my fenders so I can swing them out of the way. Gull-wings, maybe. Velcro tabs oughta hold them closed.

Actually, I'm about to replace my leaky MC, so I'll have a million-dollar view of the IP for a change.

 

Ya, I know what you mean, I just adjusted my idle.
About those fender wells let me tell you, the PO stripped the nut on the bottom of the pre-filter and I had to get in there (truck problems) so I tried one of those filter removal things and I was just bending the handle, I had one of those chain pipe wrenches but the handle was about 1.5 feet and the chain barley fit between the pre-filter and the block, after about 2 hours total I was able to get it off empty a bunch of junk out and put it back in.

Looking back on it I'm glad I had the problems because I learned so much, and found this forum, and learned a lot of free mods.

 

Yep, sticky solenoid it is. I'd forgotten everything about it, even its vertical position, since the last time I did something in this area. With the key still on, when I mustered the position and will to compress the spring enough, 'clunk' it went, the electromagnet then able to hold it up in the 'start' position. Bothers me a little that it didn't immediately spring to life once I tried to start it after manually getting the solenoid up where it needed to be, but clearly there's a problem with the shaft being sticky.

 

I finally got around to changing out that shutoff solenoid (yeah, I don't drive the truck that much...) and, well, it's not been a shining success story. At least now I have a shiny new solenoid and an intact boot, but still, on maybe-fewer annoying occasions, I have to open the hood and manually assist the solenoid in retracting, just as I did before replacing it.

So here's the question: when it's working right, does the solenoid FULLY retract, smacking itself all the way to the top of its travel? Audibly, even? (That's what both the old/new solenoid did/does when I manually assist.) Or does it just pull up "enough" to enable the IP to work? Right now, I think the latter, since on at least one occasion, after starting, I found that the solenoid wasn't even close to "smacked home" in the energized position. And with the key "on," so as to activate the solenoid, unplugging and plugging the solenoid connector does NOT cause it to move anything like full-travel - yet it will start like that, only...not always.

If solenoid IS really supposed to fully-retract & click to the limit, then my only other guess is that something in the invisible mysterious linkages down there is gummed up, dry, etc, and I'd just about have to wholesale-spray everything in the darkness down there, and pray I get some on the linkage components. Any help with more precise fix or lubrication suggestions welcome...

 

So here's the question: when it's working right, does the solenoid FULLY retract, smacking itself all the way to the top of its travel? Audibly, even?

Yes, makes a fairly loud 'SMACK' when it does, but you don't normaly hear it because the starter is cranking.

(That's what both the old/new solenoid did/does when I manually assist.) Or does it just pull up "enough" to enable the IP to work? Right now, I think the latter, since on at least one occasion, after starting, I found that the solenoid wasn't even close to "smacked home" in the energized position. And with the key "on," so as to activate the solenoid, unplugging and plugging the solenoid connector does NOT cause it to move anything like full-travel - yet it will start like that, only...not always.

Like said, yes, it's suppost to "smack home",

If solenoid IS really supposed to fully-retract & click to the limit, then my only other guess is that something in the invisible mysterious linkages down there is gummed up, dry, etc, and I'd just about have to wholesale-spray everything in the darkness down there, and pray I get some on the linkage components. Any help with more precise fix or lubrication suggestions welcome...

There is actualy two Power wires going to it, there's your 'hold' wire, and your 'pull' wire.

The hold wire gets power whenever the key is on, it holds the lever up, but doesn't have enough power to pull it up though.

The Pull wire get's power whenever the starter is engaged, it has the power to pull the lever up, but if it gets power for to long then it will overheat the solenoid.

So by the sounds of it your 'hold' wire is working perfectly, but your 'pull' wire isn't always getting power when it should.

Here's a Diagram of the system:

So I would start with getting a new fuseable link and/or relay and start there.

 

I think you're on the right track cleaning and lubing the linkages.

I've seen gasser hose get melted in less than 6 months from #2 diesel.
Even with 5% BD it gets soft in a month.

 

just if it helps see what you are dealing with.

Oh and there are two relays behind the brake reservoir, mounted on the firewall. The bigger one is the FSS relay, the other is for the fuel heater.

Actually, I'm about to replace my leaky MC, so I'll have a million-dollar view of the IP for a change.

Haha, I think I got you beat...

arty018:
if you would like any pics while in in there let me know.

 

Cowboy,

Many many thanks. I had a detailed reply ready to go about this, adding some maybe-useful-to-the-next-guy information, clicked on "Post Quick Reply," and got this BS:
"Your submission could not be processed because you have logged in since the previous page was loaded.

Please push the back button and reload the previous window."

I don't have the stomach to rework what I'd already composed, but suffice it to say that unplugging the starter low-current connector, so as to be able to hear the fuel-cutoff solenoid when it is or isn't 'smacking up' into position is very useful in diagnosing. My FSS was indeed bad, but worked about once every five tries. I couldn't tell that at all because, as you mentioned, the clunk of the solenoid is completely inaudible under the sound of the starter-motor.

Again, many thanks for the help.