Ford 3400 Gas Industrial

[Allen Goodman]

I was called out by a gentlemen who was having problems with his 3400 starting hard and dying after he would start to work it. I removed the gas line running out of the tank valve. Gas just dribbled. Drained the tank and removed the tank valve. It was nearly plugged up with debris. The valve didn't have a screen on it. Figured it should be fine since I drained the tank. Put fresh gas in and it started immediately and ran fine. A few days later he called and said it's doing the same thing, hard starting and would die after running for awhile. Figuring there must still be some debris in the tank I got a new valve with a screen. Drained the tank, installed valve and started and ran just fine. As we were talking the guy said he really don't need that big of a tractor and loader any longer and asked if I knew of a good smaller unit without a loader. I told him I have a Oliver Super 55 that I would trade for his Ford. Showed him photos and he said deal. A week later (last Friday Aug 30th) I took the Oliver. The guy had graded his driveway the day before and still had the blade attached. We disconnected the blade and I went to start it and it would only run on 2 cylinders and then backfire through the carb. Didn't have enough power to load on the trailer so I had to winch it on. Got it home and have replaced the plugs, wires, distributor cap, rotor and I even replaced the coil with a resistor coil and got rid of the ballast resistor. Still runs on 2 cylinders and backfires. Thinking maybe a rocker arm has come off or valves so far out of adjustment, so I removed valve cover everything was in place so I checked valve clearances, all within tolerance. Did a compression test this afternoon. #1 and #3 are reading 90 lbs and #2 is reading 95 lbs. What do you guys think that's causing the backfire and running on 2 cylinders? Engine overhaul time? I'm frustrated because it ran so good two weeks ago and now it doesn't. What is going on? Appreciate your thoughts on where I should go from here.

 

[mhb@ufe]

I was called out by a gentlemen who was having problems with his 3400 starting hard and dying after he would start to work it. I removed the gas line running out of the tank valve. Gas just dribbled. Drained the tank and removed the tank valve. It was nearly plugged up with debris. The valve didn't have a screen on it. Figured it should be fine since I drained the tank. Put fresh gas in and it started immediately and ran fine. A few days later he called and said it's doing the same thing, hard starting and would die after running for awhile. Figuring there must still be some debris in the tank I got a new valve with a screen. Drained the tank, installed valve and started and ran just fine. As we were talking the guy said he really don't need that big of a tractor and loader any longer and asked if I knew of a good smaller unit without a loader. I told him I have a Oliver Super 55 that I would trade for his Ford. Showed him photos and he said deal. A week later (last Friday Aug 30th) I took the Oliver. The guy had graded his driveway the day before and still had the blade attached. We disconnected the blade and I went to start it and it would only run on 2 cylinders and then backfire through the carb. Didn't have enough power to load on the trailer so I had to winch it on. Got it home and have replaced the plugs, wires, distributor cap, rotor and I even replaced the coil with a resistor coil and got rid of the ballast resistor. Still runs on 2 cylinders and backfires. Thinking maybe a rocker arm has come off or valves so far out of adjustment, so I removed valve cover everything was in place so I checked valve clearances, all within tolerance. Did a compression test this afternoon. #1 and #3 are reading 90 lbs and #2 is reading 95 lbs. What do you guys think that's causing the backfire and running on 2 cylinders? Engine overhaul time? I'm frustrated because it ran so good two weeks ago and now it doesn't. What is going on? Appreciate your thoughts on where I should go from here.

If the tank had enough dirt in it to plug the tank valve it is very possible dirt got beyond the valve and plugged the fuel system farther down the line. I would recommend cleaning the system all the way to the carburetor including the screen at the inlet of the carb.

 

[Sean in PA]

Don't forget the screen in the top of the mechanical fuel pump up at the front of the engine if it still has that pump.

 

[RedGreenGuy]

Purchased my 3400 gas after it set 7 yrs. Tank had lots of rust and junk in it, Did what you did, but gave up and had tank cleaned and lined at radiator shop. No more problems

 

[Eman85]

Sounds to me like fuel starvation, lean will backfire. You said it started immediately and ran fine after installing the new tank valve with screen. It didn't suddenly wear out enough to need an overhaul.