No start issues

[Jrgoff87]

Recently bought a 71 m35a2 and trying to get it up in running order. It was sitting for a while and the previous owner had to clean the fuel system from algae build up before it would run so I could check it out but now it takes starting fluid to start every time. Even after it's warmed up, also has a miss and pop. Which I drove it home and seemed kinda weak.

It feels like it has a fueling issues but I'm starting to wonder if it's a compression issue from being ethered to start and was hoping to get some opinions before I spend any more money on it.

Changed fuel filters, got a set of NOS injectors, cleaned the HH and did notice the plunger was kinda loose in the bore but nothing was scorn. Checked timing and it was way advanced like 1/4 inch past lds mark. Also Checked overflow valve and pressure relief valves and cleaned them. Nothing really changed the way it ran and still won't start on it's own.

In tank pump is running but don't have a gauge low enough to get a reading, but does have fuel coming back into the tank from the return line. Need to get more fittings for my gauge but I can remove the return line and dead head it with my compucheck fitting and gauge and get around 7psi from the electric pump and while cranking it'll go to around 145psi but still won't start on it's own. Also it's not making oil that I can notice

Was hoping someone might know something I'm missing before I buy a HH for it or just Cummins swap and be done lol

 

[markgjsquires]

Did it start and seem to run fine before you went through and cleaned everything? I only ask because I recently replaced a cracked hydraulic head on one of my deuces and did not realize i had not installed the "button" on the bottom of the head and it would not start. Removed it again, installed the button, reassembled and been running fine since. Perhaps if it doesn't start this could be one. I have also had the fuel adjustment nut not screwed in enough after I had to fix the fuel shut off that would keep a different deuce from starting. But I'm no expert either just a couple suggestions.

 

[Jrgoff87]

Before all this happened the PO said it started good as long as it was over 50° outside and it ran fine. It has a new button and seals. But since the algae issue it's not started on it's own. If I hold it wide open you can kinda smell fuel out the exhaust but no smoke.

Was also wondering if it's possible to put a gauge on the HH in the center or what kinda pressures it'll have there. I have a hydraulic gauge for up to 8600psi but didn't know if putting a gauge there would mess anything up with as little volume it moves.

 

[markgjsquires]

I know there is a good amount of pressure behind the center bolt on the HH. I’ve had one leak fuel out from it and it sprays pretty good. How many PSI I’m not sure. I’m just surprised you’d have to use ether to get it going shouldn’t have to. Have you cracked one of the injector lines? Did you make sure when you reinstalled the HH you lined up both timing marks. Not trying to assume you did it wrong just thinking is all. Or perhaps an issue with the fuel shut off.

 

[Jrgoff87]

Cracked them all when I replaced the injectors and had fluid from them all. Made sure none of them were clogged. I doubled checked all the timing. Did think it was weird how far off the timing was before and still ran the same when I put it in time

 

[markgjsquires]

Cracked them all when I replaced the injectors and had fluid from them all. Made sure none of them were clogged. I doubled checked all the timing. Did think it was weird how far off the timing was before and still ran the same when I put it in time

You know I have a truck that when using the starter it almost wears the batteries to nothing before it starts but for some reason when you give it a tug it pops right off. Have a way to give you a pullstart try that? Don’t ask me why it does it. I thought plugged air cleaner/intake but took filter out and no difference. I did screw the fuel screw out (to give it more fuel) and that helped a little. Hard to help diagnose without being right there. Maybe injectors got that plugged up? Can take them out and get checked.

 

[Jrgoff87]

I kinda thought it acted like an injector stuck open and that's why I replaced them and it made no noticable difference

 

[DavidWymore]

If the plunger is loose in the head, it's shot. Should fit perfectly with no perceptible slop. Pretty sure this is your issue.

Injector out of engine, connected to inj. line on HH - crank over. Injector should shoot a couple feet. ***Danger, over 3,000 PSI.

 

[Jrgoff87]

It didn't seem to have crazy pressure when I tried cranking it with the injector unhooked, but it did shoot.

Think I found a complete running engine gonna try to pick up this weekend and swap the HH and see what happens

 

[Jrgoff87]

Well cleaned and swapped the other new to me HH and she fires right up. I appreciate the help