Ford/NH 1620 loss of power after service

[dougmccabe]

Hello! new to the forum and need some help. I have a loss of power under a load. The tractor ran perfectly before the incident.
Ford 1620 HST w/FEL. 2500 hrs
I tore the hyd filter and boss off in the woods clearing some old fields. I lost all of my hydraulic fluid and had to tow the tractor back to the shed.I replaced the boss and did a complete service (Hyd oil, engine oil, air filter, fuel filter, HST filter). I bleed the fuel filter, pump and injectors. I blew comp air backwards to the tank to clean any crude from the tank discharge screen. Cleaned the fuel filter housing passages. Checked the fuel hoses.

The tractor will run and move around under low power. When placed under a load the tractor losses power and will die if the load is not released ie: let off the treadle. Everything re-checked with no change. The tractor motor does not sound the same as it did before.

Ideas... fuel delivery issue, only running on 2 cylinders, injector bad, injector pump?

Hydraulics for the FEL and 3 pt work fine.

Anyone have this issue?

Thanks!

 

[TheMadOne]

I'd guess dirt got in somehow when you lost the boss or during your service. Clean everything again.

 

[dougmccabe]

I'd guess dirt got in somehow when you lost the boss or during your service. Clean everything again.

You thinking its a hydraulic issue?

 

[TheMadOne]

Could be dirt in the valve not letting oil through. When you stomp the pedal it tries to flow, but ends up overpressuring and dumping to return. Just a theory.

 

[majorwager]

Had similar issue w/ my 1620. One of the bleed nuts at injectors on top of either manifold or valve cover was leaking, rather drawing air. The dealer tightened all of fuel line, injector connections, problem solved. How many hours on machine? When you changed fuel filter, how (steps) were taken to bleed the fuel line?. I doubt the hydraulic system is the cause of power loss. Owned my 1620 since new (1992).

 

[dougmccabe]

2500 hrs. Got it used 5 months ago. Ran great. Has a 5' HD bush hog, 72" mid mount mower. It mowed in medium gear at 2000 rpm all summer without a hiccup.
Fuel filter change was.... pull and clean filter bowl, compressed air from the fuel line back to the tank to clear any debris at the tank/fuel line discharge, cleaned all the passages of the fuel filter with brake clean and compressed air blow through, check fuel line from bowl to injectors, trimmed edges, bleed fuel at top of fuel injector pump until solid stream of fuel came through bolt hole, cracked injector lines going into cylinder until fuel spit out. Tractor started running after the first line was bleed.
I don't see where any air could be trapped after all of that. Seems odd that it started acting up after a service. I have retraced all of my steps to make sure nothing I touched was loose. Sure is making me scratch my head.
I will check the valve cover bolts.

 

[majorwager]

Not saying valve cover bolts are issue. I do believe it is a fuel line or injector issue. Too late now but compressed air to fuel tank could have stirred sentiment in the tank bottom. If debris in tank, better off removing tank and cleaning. You may want to check the new filter for obstruction. Did you inspect tank before service?, When the farm tank is filled, because new delivery is always filled under high pressure and high volume GPM, we never fuel a tractor right after a delivery. If we see the delivery, we make driver temper the delivery rate. Suspect the compressed air stirred things up in tank. After fuel filter service, (compressed air) how soon after, did you oprtate the tractor?

Just as an aside, unrelated, fuel delivery drivers are often paid by gallons delivered, not hourly. So they deliver fuel as fast as the tank will accept it, often unsetteling any matter resting on tank bottom. The compressed air could have similar result.

 

[dougmccabe]

Nothing has fixed it. I have a tractor mechanic coming by on Friday. Will post up what I find out.

 

[thepumpguysc]

When you said you bled the fuel at the TOP of the inj. pump.. do you mean you loosened the lines ON TOP of the inj. pump..
OR just the main feed line??
IF you loosened the steel lines at each cyl. ON TOP of the inj. pump.. that's probably it..
You loosened the "delivery valve holders".. They MUST BE TORQUED to 30-35 ftlbs..
Seen it a MILLION x..
Don't just go out there w/ a socket & crank down on them.. they MUST be torqued..

 

[majorwager]

Thepumpguy,
I had this issue as I had bled innector lines. The dealer tightened all the lines and problem resolved. They did not mention torque requirement and I did not witness repair but seems very logical. Hope OP has seen your comment. Great input.