M35A1 starting issues, with vid for diagnosis

[scooter01922]

M35A1 starting issues, UPDATED 10/1/09

Ok guys, another work day on the M35A1 has passed. After bleeding and bleeding the fuel system still wasn't working much at all. After consulting with gimpy and stretch ( thanks guys) I tossed some gas in the air filter and it was willing to run a few seconds that way. A bunch of gas assisted starts later it will now start and run for just a second then die, this will repeat itself over and over if you let it sit for a min or so between attempts. If you try again immediately it just cranks and sort of half tries to go. Just for the hell of it i got it to start on gas and then gave it little sputs of ether in the intake to keep it going and it sat there quite nicely like that for a good 30 seconds, as long as I kept up the spurts it ran GREAT. Has plenty of fuel in the tank and good flow at all filters , all filters were new last week. I can hear the volume of the return to the fuel tank changing somehow. One min you hear plenty splashing back in and the next nothing, its odd. Here is a vid for you guys to ponder. Oh, and here is one of boatcarpenters deuce too ( thanks again man) he wanted to see how much smoke he was getting. Not the best vid but the sound is nice

[media]http://www.youtube.com/watch?v=8ZoEnlTWdTY[/media]
[media]http://www.youtube.com/watch?v=_xd5CFxs-C0&feature=channel_page[/media]

 

[maybefixit]

Hm. Wish I knew more about those systems. The ether and other items bypass the fuel system allowing engine start, so that proves you've got good compression and cam timing. Would it make sense to loosen an injector line at the cylinder head to confirm whether fuel is being pumped to the injectors?

 

[liftman]

Seems like you might have a suction side problem from the tank to the pump. Those leaks or obstructions can be tough to find. Each component from the tank to the pump needs to be removed and inspected.

In my experience, most of the time the problem is a crack in the dip tube that goes into the fuel tank, which you can't see.

Another thing to be sure of is that the gasket for the filter isn't partially blocking the intake side of the filter base when the intake is sucking the fuel.

 

[cranetruck]

Check the fuel filters, there is a bypass valve on the filter bracket, so you'll have a return flow even when the filters are blocked.

 

[Boatcarpenter]

Bjorn,
We have bled the system a lot. We loosened all the fuel lines at the injectors so they were only held by a couple of threads so that we could actually see the fuel pulsing out, not just a drip. They all would shoot out a good stream when it was their turn to fire. My sense is though that we are not getting enough pressure to pop the injectors. Likely that one or two injectors might be bad after sitting so long, but not all of them. Could I get a 2500 lb pressure gauge and adapt to the injector line at the injector to see what we are actually getting for pressure? I think that would tell us a lot. Might tell us that the pump is not providing the pressure we need. Scooter has a spare hydraulic head which we could then try. Short of pulling all the injectors and getting them tested, I think this might give us a clue. Don't really want to shoot from the hip here and just start replacing parts. Would like to figure out what parts to replace.
Any thoughts?
BC

 

[gimpyrobb]

Tow it home! Then you can work on it at your liesure. A 4hr drive is just crazy. Once home I'd dump the tank and clean it. Run pressureized air backward from the IP through the fuel lines so you know there is no restrictions. If you got it to fire on its own for 30ish seconds, sounds like it just needs more running to bleed the air from the injector lines. Your problem sounds ALOT like what happened to me when my intank pump went out. It was a PAIN to get her running again. Once I got it running, I used up the fuel in the tank and pulled it out. Turned out the bottom fell off the in tank pump. No problems since.

 

[scooter01922]

I wish it was as simple as the intank being crapped out. Its been in and out of that tank no less than 3 or 4 times now it works, trust me I have some guesses at what it might be but i think i'm going to put all effort into getting the M35A2 to aberdeen and back and then tow this truck home where i can tinker a bit easier. Not that BC dosen't bring every tool under the sun for me to use but it would be nice to be working in my own driveway.

 

[dm22630]

Are you sure your injector pump is working? The fuel pump would push fuel through it & it would squirt out of any point from the tank until the last injector return line.....it just would not pressurize the fuel enough to make the engine run.

Remove the fuel pump power cord, turn the accessory power on, and then open a fuel line AFTER the injector pump & see if anything comes out. The injector pump will suck fuel out of the tank without the fuel pump running (unless there is air in the lines....so dont crack open anything before the IP).

*** You may have to be cranking in order for the injector pump to "run" ***

Worth a shot....

 

[Stretch44875]

DO NOT install a pressure gauge on the injector line. That will dead head the pump, and something will blow. May be able to pull the injectors, and hook up the injector lines to see if they are spraying. Don't put any body parts in the way of the spray, good way to end up with a hole in ya.

Dennis

 

[Chevytruck]

you can try a fuel can cheat to see if the fuel lines are bad?

(just a suggestion)

 

[scooter01922]

In order of questions asked....... With the in tank switched off the IP does pump fuel to the injectors. All injectors seem to get a couple really good squirts ( lines off all the injectors) then the flow diminishes. Sort of what i would expect as it starts and them dies. So it seems to be injecting for a few revolutions then for whatever reason slows down. Fuel obstruction somewhere is my number one suspect. Has enought to start the engine but not enough to keep it running once the IP starts to demand some more fuel.

Good to know stretch, its a good suggstion BC but believe me if stretches advice wasn't enough the price tag on a gauge rated high enough to test is. They are NOT cheap, i looked. Even with my work discount you don't even wanna know.

Another good suggestion Ct, i might just have to go that route if i can't seem to clear whatever is obstructing things.

 

[drgreg]

Go easy on the ether, it does not have any lubrication and can cause the cylinder to score.

 

[scooter01922]

The hyd head looks like a nice easy swap, i have a spare pump to grab one off of so i might just do that. After i flush the lines and replace any filters that look cruddy (again) That seems like the easiest thing.

 

[JuicyDeuce]

My Duece is having the same problem, it will run on a quick shot of ether for about 10 secs and die its got compression and timing plus the engine was rebuilt in 1989. The pump is getting fuel from the tank, and the lines have been bled. BTW i'm not using a lot of ether don't want scoring...

The truck did sit for two months without being started and ran perfect before then. The diesel is old of course, its slightly green and stinks to hell and back.

Aside from the diesel being bad., should i get the pump rebuilt or how should i go about it, where can i order fuel components?

I printed out the Trouble Shooting Manual for the LDS-465-1 lucky me my duece is a 1968, same year on the manual.


Thanks guys,

 

[scooter01922]

2 months is nothing for diesel to sit so you can pretty much cross that off the list.DID you check to see if the plunger is moving?? 2 months seems kinda short for it to get stuck but you never know. I'll fill everyone in on my fix to this issue once i get back from aberdeen i can start to focus back on this project a bit more. Just going to towbar it home when i take the deuce over there to get the front axle i need for the 108 from the parts truck.

 

[JuicyDeuce]

2 months is nothing for diesel to sit so you can pretty much cross that off the list.DID you check to see if the plunger is moving?? 2 months seems kinda short for it to get stuck but you never know. I'll fill everyone in on my fix to this issue once i get back from aberdeen i can start to focus back on this project a bit more. Just going to towbar it home when i take the deuce over there to get the front axle i need for the 108 from the parts truck.

Trying to get my knowledge together, but where exactly is the plunger and how do i check it?

I can reference the trouble shooting manual as well....

if the whole injection pump needs to be replaced, where do i go to buy one and how much are they?

 

[scooter01922]

Any of the surplus dealers would happily sell you one, check E-bay they pop up there from time to time. The plunger is located under the bolt in the center of the IP hydraulic head. Make sure you clean the area really, really well before you take it out, getting crud in there is really bad. Then take a nice clean pencil and put it on top of what you see in there. Go disconnect the in tank pump power supply so you don't shoot fuel all over and then give it a crank. If you see the pencil hopping up and down really rapidly then the plunder is working, if not then its stuck.

 

[littlebob]

I'm sure your humidity isn't what we have here, but have you drained the sumps on all three filter canister and the tank of condensation? Haven't had any problems yet with
mine cranking up every month or so while I'm trying to get it back together but I did check
them once since I changed filters and found an amazing amount of water in the sumps about a year after sitting with only 1/3 tank of fuel.

 

[lavarok]

Chill63 and I recently fixed a fuel (injector) pump issue on his new deuce. The bolts that attached the gear to the pump shaft were unattached!!! Take the front cover off the pump housing to reveal the gear assembly. Check to make sure that the bolts are installed properly and tight. Never under estimate the lack of skills or knowledge of the last guy that worked on your truck. Its a five minute check that could save you hours of troubleshooting. I'm just glad Chris decided to pull the pump BEFORE buying a new one. It was only during the process of pump removal the problem was found. Once fixed, she fired right up.

 

[Boatcarpenter]

Didn't get to work on the A1 Sat., but spent some time with scooter trying to get the front axle out from under the parts truck. Springs and hangers were already gone. He needs the axle for his 108. If he hadn't been rear ended by a Jetta on the way over and used up a lot of time we might have gotten it out but ran out of time.
BC