1078 A0 engine starts, runs for anywhere between 8-30 seconds... [newbie ? buried in a long post]

[thomaspc]

Just got my truck delivered Wednesday, and to save the truck driver the headache of driving down the 2 mile dirt road to my house I had him drop it just a few hundred yards off the highway...and I need to get it home. To start I replaced the four dead batteries with two new ones. That got it to crank. While at lunch I hit up the auto-parts places for filters, relays etc. Nobody had 24v relays so I called Jeff Bezos and he's sending a couple. Had another bonding session this afternoon, and troubleshot that the fuel solenoid has voltage. hmm. What was that ass-umption at the beginning of this procedure? oh yeah, fuel in the tank, etc. [etc = primed] You'd think after 22 years in the Air Force I'd remember how to read a T.O. Anyways, with the cab up, priming is way easier. Didn't feel right, so I loosened the connection from the filter to the engine and kept priming the air out till it was fuel. Tightened, cranked, and occasionally it started and ran briefly. Repeated this procedure 48,00 more times and suddenly that definition of insanity hit me. Oddly enough, it ran long enough [cumulative total] to build up some air pressure. Oh..the one place [rhymes with O'Smiley's] didn't have a fuel filter in stock but would have it this afternoon... now 40 minutes away and closed. Bought it, don't have it. Oh, I did dump 15 gallons of fresh diesel in. Guage shows 1/2, status unknown. My options;
- Get this thing actually running with some pearls of wisdom from you guys...
- Get air in the system so I have brakes [currently caged] and can tow it. Haven't built a hose to attach to the glad-hands, but I do have a handy portable compressor.
- Tow it from the front with my backhoe, with a second vehicle strapped to the back to keep it from hitting me...gettin' sketchy, but where's your sense of adventure?
-Go get that fuel filter and repeat the priming process.
- Do an unauthorized borrow of a trailer from work.

 

[tennmogger]

Sure sounds like fuel starvation as you are describing. You mentioned priming and opening a tubing connection. Do you mean at the priming button on the filter at the right (engine rear) as you look in from the drivers side? That pre-filter water separator is followed by the real filter mounted on the engine. That filter has a priming port to open and get flow out of it. I am guessing you didn't open that final filter priming port since you didn't mention it. Once you prime the final filter it should keep running.

 

[Ronmar]

It does sound like fuel. If you pump the system full of fuel you should have a firm primer bulb, as you hydraulically push fuel past the pressure regulator. You should be able to hear fuel falling back into the tank from the return line as you pump if its quiet. it is also redicously easy for the flapper bypass to get stuck which pretty quickly renders the primer ineffective or completely useless(Why I did the 2nd video)

Have you seen these?

 

[thomaspc]

Sure sounds like fuel starvation as you are describing. You mentioned priming and opening a tubing connection. Do you mean at the priming button on the filter at the right (engine rear) as you look in from the drivers side? That pre-filter water separator is followed by the real filter mounted on the engine. That filter has a priming port to open and get flow out of it. I am guessing you didn't open that final filter priming port since you didn't mention it. Once you prime the final filter it should keep running.

Nope, didn't know about that priming port. I was just loosening a 3/4 in coupling and trying to bleed off the air.

 

[thomaspc]

It does sound like fuel. If you pump the system full of fuel you should have a firm primer bulb, as you hydraulically push fuel past the pressure regulator. You should be able to hear fuel falling back into the tank from the return line as you pump if its quiet. it is also redicously easy for the flapper bypass to get stuck which pretty quickly renders the primer ineffective or completely useless(Why I did the 2nd video)

Have you seen these?

Oddly enough, I've seen the last video, but I've been lurking for a while and now that I actually have a truck I can't find any of the helpful stuff I found but didn't need before. At first, the primer didn't seem to be working as it didn't get harder to push. As I loosened and re=tightened the connector I could pump the air out, get mostly fuel, tighten it up, hear fuel being pumped, and it got harder to push. Thought I was on the right track but never got any further. My plan is to go get the new fuel filter in the morning, since I was going to change it anyway, and try priming it again. Is there a way to coerce the flapper valve?
I did at one point undo the 2nd connector that goes back to the tank, but didn't get any fuel there, and wasn't sure that I should. During the brief periods the truck was running, it did build air pressure, maybe 60 psi, but I could hear air leaking at the manifold. Might be normal as the brakes are caged so I never tried to release them. Should I be hearing that?

 

[Ronmar]

Oddly enough, I've seen the last video, but I've been lurking for a while and now that I actually have a truck I can't find any of the helpful stuff I found but didn't need before. At first, the primer didn't seem to be working as it didn't get harder to push. As I loosened and re=tightened the connector I could pump the air out, get mostly fuel, tighten it up, hear fuel being pumped, and it got harder to push. Thought I was on the right track but never got any further. My plan is to go get the new fuel filter in the morning, since I was going to change it anyway, and try priming it again. Is there a way to coerce the flapper valve?
I did at one point undo the 2nd connector that goes back to the tank, but didn't get any fuel there, and wasn't sure that I should. During the brief periods the truck was running, it did build air pressure, maybe 60 psi, but I could hear air leaking at the manifold. Might be normal as the brakes are caged so I never tried to release them. Should I be hearing that?

You should be able to get fuel at every fitting after the primer when pumping. If the primer is working, you should be able to pump fuel completely thru the system in under 40 or so pump strokes if the filters are full of fuel. In the first vid I showed a plug on top of the secondary filter. That is a good place to purge air. You can also loosen that fitting above the governor(after the pressure regulator block) where the hose that returns to the tank is connected. Connect a clear hose and run it into a container so you don't pour fuel all over. Pump till you get fuel, then pump till you stop getting air. If it keeps getting air, you probably have a leak on the line from tank to primary filter, or one of its fittings are loose. It must be air tight…

If you remove the primary filter/water separater under the primer and look up into the filter housing, you will see the bypass flapper. It is held in place by a Phillips head machine screw. Just undo that screw and you can remove it to clean it and its seat. My primer didnt work when I got my truck. I found a large horse or camel hair stuck thru it if that flapper won’t seal, the bulb will just pump in a circle in the head of the filter housing. That flapper has to seal in order for the bulb to lift fuel from the tank. That is why I came up with the easy way to test it in the video. Remove the inlet hose fitting on the rear of the filter, hold your finger over the inlet to seal it and depress the primer. It should stay depressed all by itself until you remove your finger And break the seal.

like I mention in the video, it is way easier to suck in air than it is to lift fuel, so everything must be vacume tight in the system or it will suck air.

You shouldn’t hear air leaking from the brake system, and it must build and hold air. The fact you got to 60 or so is a good sign, but you will need to find the air leaks and kill them

An external air compressor is the better way to hunt these. It is hard to chase down leaks when the cat is purring… if you apply air to the front red emer gladhand, it will charge the system, but it also releases the park brakes. Something you are already dealing with as you said yours are caged, so you have no park brakes, just something I thought I would mention for the future when y0u will want to do this. Always chock the wheels before you connect air

 

[thomaspc]

You should be able to get fuel at every fitting after the primer when pumping. If the primer is working, you should be able to pump fuel completely thru the system in under 40 or so pump strokes if the filters are full of fuel. In the first vid I showed a plug on top of the secondary filter. That is a good place to purge air. You can also loosen that fitting above the governor(after the pressure regulator block) where the hose that returns to the tank is connected. Connect a clear hose and run it into a container so you don't pour fuel all over. Pump till you get fuel, then pump till you stop getting air. If it keeps getting air, you probably have a leak on the line from tank to primary filter, or one of its fittings are loose. It must be air tight…

If you remove the primary filter/water separater under the primer and look up into the filter housing, you will see the bypass flapper. It is held in place by a Phillips head machine screw. Just undo that screw and you can remove it to clean it and its seat. My primer didnt work when I got my truck. I found a large horse or camel hair stuck thru it if that flapper won’t seal, the bulb will just pump in a circle in the head of the filter housing. That flapper has to seal in order for the bulb to lift fuel from the tank. That is why I came up with the easy way to test it in the video. Remove the inlet hose fitting on the rear of the filter, hold your finger over the inlet to seal it and depress the primer. It should stay depressed all by itself until you remove your finger And break the seal.

like I mention in the video, it is way easier to suck in air than it is to lift fuel, so everything must be vacume tight in the system or it will suck air.

You shouldn’t hear air leaking from the brake system, and it must build and hold air. The fact you got to 60 or so is a good sign, but you will need to find the air leaks and kill them

An external air compressor is the better way to hunt these. It is hard to chase down leaks when the cat is purring… if you apply air to the front red emer gladhand, it will charge the system, but it also releases the park brakes. Something you are already dealing with as you said yours are caged, so you have no park brakes, just something I thought I would mention for the future when y0u will want to do this. Always chock the wheels before you connect air

This still sucks...air, that is. Didn't find any loose connections, and the primer seems to work. Tried putting my finger over the hole and while the black bulb doesn't stay depressed, you can hear the plunger release when you let go. Tried cheating by pouring a little fuel in the primer port but it spilled over pretty quick. Still, it ran for 15-20 seconds after that so I went and got the filter and changed it. Filled it with fuel before I screwed it on, primed it, and it ran for at least a minute. Was even able to pull the throttle cable and rev it up a few times. After it dies, it needs to be primed a lot. My thumbs, palms, and arms are tired. Pretty sure the slight noise I hear while priming is air being pushed out somewhere, but then it does get hard to push and may or may not run after that. Couldn't get the fuel filter / water separator off, I need the wrench with the rubber strap. [I have one, in CA] I hate having tools in 2 states... Murphy's law.
Tomorrow I'm gonna move it, and I'm toying with the idea of building a temp fuel line that I can use with a temp fuel source just for troubleshooting. But first, I need to get that other filter off and check the flapper valve etc.

 

[Ronmar]

The primer doesnt have a “plunger” other than that handle that is part of the diaphragm assembly. If you hold a seal on the inlet and push the black button in, it will stay in if it is sealed. Just took a vid of mine, stays in untill I remove my finger… give me a bit to upload it…

ok, here is a link to a primer demo…

 

[coachgeo]

Tomorrow I'm gonna move it, and I'm toying with the idea of building a temp fuel line that I can use with a temp fuel source just for troubleshooting. But first, I need to get that other filter off and check the flapper valve etc.

Temporary 12 or 24v elec. fuel pump right at the tank (or tempory tank) really makes priming... or overcoming air leaks so you can drive it..... lot easier.

 

[Third From Texas]

If you only need to drive it less than a mile, could you gravity feed it with a fuel can and a short hose. Eliminate any leaks or pump issues?

Get it to the barn at least.

 

[Floridianson]

If you only need to drive it less than a mile, could you gravity feed it with a fuel can and a short hose.

Almost sounds like engine is not holding rail pressure. I would say no on the gravity feed. Believe Fuzzttoster did a thread about the check valves to check that build / hold the rail pressure. You can on any common rail install gage and check rail pressures.

 

[Suprman]

I had a truck that did that it was sucking in air from a crack in the hose from the fuel tank to the primer separator. You can make a temporary one with quick fittings and fuel line.

 

[chucky]

Is the cab up ? If so the next time u get it running for a few seconds put someone over on the passenger side and see if the 2 lights on the altenator are blinking green or not and you might put a meter on the fuel solenoid before during and after the get it running cycle and see if you were getting 24v coming too the solenoid while running then as soon as it stalls get a reading and if its less than 22v the rack is closing and stopping the flow of fuel to the injectors sometimes when the batteries are rite on the edge of charged/going bad there may be enough amps to engage the starter but then the batteries may take a droop after that hit and if the solenoid see 22 v it aint running ! I had this problem till i got my batteries sorted out then never had it again . If the altenator isnt putting out the batts are just enough to spin her over before spent for a minute .

 

[Ronmar]

@chucky its an A0, so probably no lights on the alternator/regulator… A bad connection can do the same thing to the run solenoid on the governor…

 

[chucky]

@chucky its an A0, so probably no lights on the alternator/regulator… A bad connection can do the same thing to the run solenoid on the governor…

Mine is an AO with lights on it . And if he doesnt atleast put a meter on the alt or battery to see if it is charging in the brief seconds it runs

 

[chucky]

When i had the problem i liked to never figured that out till i ran a jumper wire (12g ) from the 24v batteies in the truck direct to the solenoid and boom just like a sewing machine this truck has always fired in a milisecond every since i got it and even in winter .

 

[Ronmar]

Yea they ran out of the older alts at some point, and you will find some A0 trucks with the newer alt if they had a failure…

 

[GeneralDisorder]

Your fuel hoses are probably shot. Here's one off my 2008 A1R:

 

[thomaspc]

The primer doesnt have a “plunger” other than that handle that is part of the diaphragm assembly. If you hold a seal on the inlet and push the black button in, it will stay in if it is sealed. Just took a vid of mine, stays in untill I remove my finger… give me a bit to upload it…

ok, here is a link to a primer demo…

Took the filter off, took off the flapper valve, cleaned it up and put it back together, then had zero priming. Took it back apart, loosened the screw and adjusted the position of the valve and that got it priming again. On mine the bulb is oversprayed a bit with yellow, and it doesn't seem efficient, so I ordered one from MME. However, I did get the truck running for over a minute at a time, but not consistently. I'm sure there was some crappy fuel in that I should've drained, but I added 20 gallons and the fact that I keep having to prime it gets us back to a leak. I'm going to build a hose tomorrow.

 

[thomaspc]

Is the cab up ? If so the next time u get it running for a few seconds put someone over on the passenger side and see if the 2 lights on the altenator are blinking green or not and you might put a meter on the fuel solenoid before during and after the get it running cycle and see if you were getting 24v coming too the solenoid while running then as soon as it stalls get a reading and if its less than 22v the rack is closing and stopping the flow of fuel to the injectors sometimes when the batteries are rite on the edge of charged/going bad there may be enough amps to engage the starter but then the batteries may take a droop after that hit and if the solenoid see 22 v it aint running ! I had this problem till i got my batteries sorted out then never had it again . If the altenator isnt putting out the batts are just enough to spin her over before spent for a minute .

It has two new batteries, and while it was briefly running the alternator seems to be working as the voltage jumps up.