Ford 755A Backhoe won't start.

[Dodgewade]

I bought a 1986 Ford 755A backhoe on .gov site that said, hasn't been started in a couple years. Stated the starter was bad. I know I bought a pig in a poke, but it is what it is.

I've had the starter repaired, couldn't i get it to turn over (figure it's a safety switch) so I cross out the solenoid to crank it over. I bleed the fuel lines to the outlet lines on top of the pump. So I decided to use some ether. It never hit or made any sort of sound to indicate it was trying to start. Since there was a couple old empty cans of ether leading in the floor, makes me think it could have some bent pushrods at the least. I would have thought it would have at least hit a few licks with the ether, but it never did.

Any advice would be greatly appreciated.

Thanks Wade

 

[thepumpguysc]

You have to make sure the pump is pumping.. its a Simms pump, right?
Remove the side cover on the pump & see if the control rack is moving.. pull/push the stop.
There should be a bleed screw on the side of the pump, 1/2" plug, just below the steel lines.. opposite the inlet line. Bleed the air..
Loosen the lines AT the injectors to see if its pumping..

 

[Dodgewade]

I'll be back on it Tuesday and check this. Just thinking out loud, you would think it would at least hit on ether.
I was getting fuel to two of the injector line (1 & 4) that I cracked/loosen before I stopped trying yesterday.

 

[thepumpguysc]

Loosen ALL of them at the same time..
Taking off the side cover will allow u to SEE if the inside of the pump is working..{pumping}
The plungers stick & the tappets wont go up & down to deliver fuel..
Springs will break & the control rack will stick..
Does this model take oil?? 90% of the Simms pumps require their own engine oil.. the other 10% are engine oil fed, from the motor..
Theres a drain plug on the bottom.. a "FULL" plug on the side & a big "FILL" plug on top..

 

[Dodgewade]

Took a few days off, trying to get caught up on bush hogging. I will definitely check that for sure.


Thanks

 

[Dodgewade]

The pump is a Minimec. It does have a cover and all of them things in there seem to be working as they should. The injectors are getting fuel. Cracking the lines at the injectors causes fuel to be spayed out on the head.
At one time today, I think the first time we tried to start it, while putting a little ether it actually sounded like it hit once or twice. (maybe). Before I quit, all I would get when spraying some ether in it was some sort of knock while it was turning over. I did find I wasn't getting fuel to the pump and it was going to the filter, but no further. I could pump it up with the hand pump, crack the bleed screw on top and fuel would spray everything. But I couldn't get any to the pump. The filter looked as if it had been changed, I checked it for water but took a minute to find the fuel opportunity. Whom every changed the fuel filter left the old gasket in place and put a new one on the filter when it was installed. I pulled one of these gaskets /orings out and I got fuel to the pump then.
The shut off is very hard to operate. Cannot operate it with the shut off cable. Worked on throttle and shut off all weekend. I think it would run the fuel shut off would get better.
I pulled the valve cover this afternoon and didn't see any bent push rods.

With it not making an attempt to run on ether, I would have thought it would run until the ether was gone.

The machine isn't ragged out, or doesn't look too have been abused. With 31 - 3600 on the clock (don't remember which) it should have a lot of life left in it.

I'm stumped. Maybe it just doesn't have enough compression?

Thanks for the advise. What should I try now?

Thanks Wade.

 

[jimg984]

have you checked to see if the return line is open to the fuel tank?

 

[Welder Dave]

If it had an overdose of ether it could be shot in very few hours. A compression test might be a good starting point.

 

[thepumpguysc]

X2 on Dave's post..
The inj. pump NEEDS ALOT of FEED FUEL.. so if your supply pump isn't pumping enough TO THE inj. pump, it wont pump enough fuel to open the injectors..
You "could" remove one of the injectors, turn it upside down, hook the line back up, so the tip of the injector is up in the air, {or hanging outside the motor} & SEE if its actually pumping fuel into the cylinder..
WARNING>> Spray from an injector WILL penetrate your skin!!! DO NOT get near the spray.!!!
Its a simple test with good diagnostic results.. no money involved..
The FEED fuel TO the pump needs to be in the 8psi minimum range.. 8-12 psi is optimum..
Its OK to bend the steel line SLIGHTLY.. NO sharp bends tho..
Good luck.. & let us know how it goes..
OR you "could" rent/borrow a compression tester from the parts store.. {tool rental}
BUT> "I" would do the injector test first.. just to SEE if its fireing..

 

[Delmer]

An 86 govt surplus backhoe "that hasn't run in a couple years" most likely ran last in 98. If you're getting fuel out of the injection lines at the injector then you're in good shape. I'd disconnect the tank, even if you drained it and refilled with fresh extra virgin dino diesel, and run off a small plastic temporary tank. Even a one gallon lawn mower tank, or hand sprayer tank will work nice. Get some #1 diesel, and mix some cetane boost to the max recomendation. Don't recirculate it back to that tank until it runs, use that for flushing the old stale fuel out of the filter, pump and lines. Then try to crank it when it's hot outside, use a tiny bit of ether, if it knocks then it's too much ether. Sure wouldn't hurt to pull all the injectors and hook them up to see if you're getting a spray pattern or if they're just dribbling. If there's no spray, it won't start. and it's possible that the fuel in the injector lines and injectors turned to gloop since it ran last.

 

[Dodgewade]

I ordered a fuel supply pump and once it gets here and after I get it on, I will give everyone's suggestions a try.
It has a tank full of fuel that will need to come out to replace. Trying it will a smaller amount might be the way to go.
You're probably right Delmer, about how long it's been since it ran. I had a friend to go get it and one of the guys where it was located went to school with him. And he has worked theft for twenty years. He said during the loading, if was a strong machine and all he knew was they had got the starter rebuilt and after putting it back on it would only spin but never made the engine turn over. The two gaskets on the filter tell me someone was doing something to the fuel when they quit or stopped working on it. Injector line to number one has been replaced and the clamp holding the other injector line is missing a bolt. It just blows my mind that is would not hit on the ether. Typically one would run /Rev up until the ether ran out.

Thanks for the help guys.

Wade

 

[Dodgewade]

Update, killer news!
I've been tied up with work and other opportunities but finally had a chance to get back on it. Order me a compression set for diesels. Finally came in today.
No cylinder has any compression. I pulled all the injectors tried each cylinder with all the other injectors still out.
The needle never moved on the gauge.
So next step should be?
Pulling the head maybe?
Thanks for your advice.

 

[Grady]

Some old ford tractors had a decompression system built into the head controlled manually by a lever in the front of the head by the valve cover. I'm not a ford guy so I don't know when [or if] they ended that design - but I didn't think they still did that in the 80's. You said you pulled the valve cover - Did you crank it to see the valves move?

 

[thepumpguysc]

WOW.. I'v only seen 1 diesel engine in my life w/ ZERO compression.. & that was a BRAND NEW JD..
I mean brand new.. w/ 0 hrs on it.. it had NO RINGS on the pistons.. lol
Are u sure your doing it right?? did u use a copper gasket on the bottom of your adaptor?? Its in there nice & tight w/ no compr. leaking out around it?? Are u sure the gauge works?? Hook up any adaptor that came in the kit & hit it w/ some compressed air.. your mouth wont work.. gotta be from a compressor..

 

[Dodgewade]

WOW.. I'v only seen 1 diesel engine in my life w/ ZERO compression.. & that was a BRAND NEW JD..
I mean brand new.. w/ 0 hrs on it.. it had NO RINGS on the pistons.. lol
Are u sure your doing it right?? did u use a copper gasket on the bottom of your adaptor?? Its in there nice & tight w/ no compr. leaking out around it?? Are u sure the gauge works?? Hook up any adaptor that came in the kit & hit it w/ some compressed air.. your mouth wont work.. gotta be from a compressor..

After checking the last cylinder I sorta felt it should Have had at least some. Seems the gauge starred at a 100psi. Don't remember exactly. I looked at the adapter that goes on the end that the copper washer fit on and there was a rubber orings or something insure it. I put it back on tightened it hand tight and could still blow through it. Maybe it squeezed shut over the opening sealing off any compression.

I'll check the gauge this evening to ensure it works.

I did have a copper ring on it. Held my hand around the adapter while turning the engine over and didn't feel any air that may have been escaping.

Will update will results.

 

[thepumpguysc]

Don't take this the wrong way but>> you are using the STARTER to SPIN the engine aren't you?

 

[Dodgewade]

Don't take this the wrong way but>> you are using the STARTER to SPIN the engine aren't you?

Yes, I stand by the injector pump so I can cross out starter with a screwdriver and observe. Nothing seems to be leaking such as the compression tester.

 

[Dodgewade]

Some old ford tractors had a decompression system built into the head controlled manually by a lever in the front of the head by the valve cover. I'm not a ford guy so I don't know when [or if] they ended that design - but I didn't think they still did that in the 80's. You said you pulled the valve cover - Did you crank it to see the valves move?

The valve cover is just sitting in place. I had it off and there valves were opening and closing.

 

[Dodgewade]

Gauge on compression test worked when I put shop air on it. Found rubber gasket between the tester and adapter was closing up not letting any thing get to the gauge. Trimmed rubber down, got some results this time.
#1 - 100psi
#2 - 100psi
#3 - 30psi
#4 - 25-30
Checked the push rods again and none seem to be bent. All of the rockers I checked had some clearance, but nothing out of line.
Suggestions? Looks like the head will need to come off?

 

[thepumpguysc]

That's a bummer.. no wonder it wouldn't hit on the juice..
Looks like u bought yourself a project.. Get a book, a gasket kit & go to town on er..
Good luck
Incase u don't know>> a diesel engine has to have 300 psi {min.} to start/run..