Won't Fire

[smclaughlin81]

So still working on my 2120 Ford NH. Had a blown head gasket (believed), dismantled what was needed to pull the head off. Gasket looked good other than one small spot, where I believe it had blown through between the cylinders. Anyway, cleaned up the head, block, everything looked really good actually, ordered a new gasket and put it on. I reused the head bolts, torqued everything, reassembled. Engine won't fire, has fuel, has air, runs on starting fluid, but nothing without. It chugs all kinds of smoke out. I've spent hours and burned up one starter trying to get it to fire off, but nothing. I'm going to do a compression check, it's all that's left. Fuel, air, combustion... but not if no or low compression. Any other ideas? Fuel solenoid is working properly.

 

[oldnslo]

If runs on starting fluid Are you sure it is getting fuel at the proper time and in the proper amount? Once firing on starter fluid it should run even with low compression since that is frequently why starting fluid was used on older diesel’s

 

[smclaughlin81]

Well, when I pulled the tractor in the shop, I removed what was necessary to get the head off, I never turned the engine, moved the tractor, anything. Just removed the injection lines. I have fuel squirting at all 4 injectors. Nothing has changed

 

[smclaughlin81]

I just did a compression test on all 4 cylinders. Each one was a scoche over 300 psi.

 

[thepumpguysc]

What about push rods and valve settings.??

 

[smclaughlin81]

Push rods were all in good shape, i haven't checked the valves. Tractor has 980 hours on it.

 

[Happy in NC]

Double check that fuel solenoid, A wise man on here told me that even if it works on the bench it doesn't mean it works in the tractor. He was right. Blew a fuse that had been added in line for some reason. My .02

 

[smclaughlin81]

Double check that fuel solenoid, A wise man on here told me that even if it works on the bench it doesn't mean it works in the tractor. He was right. Blew a fuse that had been added in line for some reason. My .02

Believe me, I've checked it. It is working properly....

 

[rScotty]

Believe me, I've checked it. It is working properly....

If it fires on starter fluid but chugs on fuel, that sure sounds like cylnders are not getting fuel at the proper time and sequence. Somehow the injector pump or injectors has gotten out of time.
That's easy to check, and on an old style diesel there is almost nothing else it could be.
rScotty

 

[oldnslo]

If you removed the head did you reset the valve clearances upon reassembly? If my memory is accurate 300 PSI is on the low end for a diesel.

 

[Williy]

You made a BIG mistake by using the same head bolts
because :

Bolt Failure: Stretched or damaged bolts may not be able to withstand the pressure of combustion, leading to failure.

Leaks: Reused bolts may not seal properly, resulting in leaks of combustion gases or coolant.

Engine Damage: Severe bolt failure can cause damage to the cylinder head or engine block.

 

[smclaughlin81]

I checked the shop manual again for compression, it says 356 psi +/- 50 psi. I measured it at 305ish, so I think that's within spec. I went through and adjusted the valves, book said .012 on intake and exhaust.

 

[smclaughlin81]

Well after banging my head against the wall on this, I decided to pull the head back off. I have ordered a new head gasket and a new set of head bolts. I believe I misunderstood the compression specs in the manual, I believe it is supposed to be 356 psi. All four tested the same at 305 ish. So, I am assuming the head bolts, being reused were stretched and not really tightening the way they needed to even though they were torquing to the correct spec. I'm out of ideas.

 

[thepumpguysc]

Do u know the backwoods way of checking if the valves are seating.??
Just take a spray can of brake cleaner and spray it on the valves on the rocker arm side, while the head is on it’s side..
If the valves aren’t seating, the b/c will leak on thru the combustion side…(around the valves)

 

[rScotty]

Do u know the backwoods way of checking if the valves are seating.??
Just take a spray can of brake cleaner and spray it on the valves on the rocker arm side, while the head is on it’s side..
If the valves aren’t seating, the b/c will leak on thru the combustion side…(around the valves)

I think you are paying too much attention to the compression readings. They seem close enough to me. A compression test is not adiabatic. Compression readings depend a lot on how long you crank it and at what speed.
If you can torque the head bolts to specs, then whether the bolts were stretched or not doesn't matter. They they are OK.
If it runs a few strokes on starting fluid on a rag... but will not continue on its own.... then that seems to me to be fuel injection.
I'd check the injector pump timing and then check that the injectors are spraying.
rScotty

 

[smclaughlin81]

I don't entirely disagree on the timing, but how did it get out of time? That's what puzzles me. I pulled the injectors, I am going to have them cleaned up and pop tested. Keep in mind, tractor only has 900 or so hours on it, although 30 years old. I will check the valves for leaking while the head is off. Just waiting now for the new head gasket and head bolts. Troubleshooting is getting spendy

 

[smclaughlin81]

When I started this whole fiasco, tractor was running fine, normal power, drove it in the shop and shut it off. Tractor was never moved, engine wasn't turned over, nothing. Literally took the head off, put new gasket on it, put head back on with original head bolts, torqued them and no starty start... I went and talked with a local diesel pump repair shop, they were convinced it wasn't a pump issue because the thing smokes like hell when you crank it over, chugs grayish black smoke. So one would assume, it's getting fuel. It's getting air, so what's left? I could pull the pump off, albeit a chore if not necessary and have it tested. Pumps getting fuel, I have fuel at the bleed scew on the pump and at each injector when I break the lines free, get a strong spurt. Just not a lot to these engines.

 

[dodge man]

What made you think the head gasket was blown to start with? You THOUGHT the head gasket was blown. Was something else really the problem. I’m just throwing out ideas.

 

[smclaughlin81]

I was using it one day and noticed after sitting idling for a few minutes there was a good size puddle of oil on the ground coming from the breather tube on the valve cover. Engine was running fine, wasn't hot, I was just grading the driveway. I started researching online to see what would cause this oil to be leakingout, seemed to be increased crank case pressure was what everyone said. Either caused by compression leaking into other cylinders or the off chance that the rings may have lined up and let the compression by that way? The oil level was normal, no fuel in the oil, so I "assumed" that it was likely the head gasket. And here we are...

 

[dodge man]

That makes sense. I thought there might have been another indication of a problem. Doesn’t sound like it?