Changed fuel injection pump oil and now Ford 1700 will only idle

[pclausen]

Tractor has been running absolutely perfect, and I decided to do some preventive maintenance by replacing the oil in the fuel injection pump.

This 1700 only has 400 hours on it. I have one of the injection pumps that lacks the drain and check plugs. This is despite having the following sticker on the fuel tank:

I have read here that others have the same pump housing as I, and the way to drain it, is to loosen the side cover. I did so, and out came some nasty black oil, but not much at all, only 1/2 oz or so. Before tightening the side cover back up, I poured some fresh oil in the filler hole to flush out some more of the nasty old oil. After that drained out, I tightened the side cover back up and then filled the pump with 2 oz of fresh engine oil (Rotella 15W40 synthetic) via the plug on top of the housing (green arrow in pic below).

I then started it back up, but was unable to get the rpms past idle, regardless of throttle position. I then figured that perhaps 2 oz of oil was too much, so I drained the injector pump again, and refilled with just 1/2 oz. No difference. Starts right up, but won't go past idle rpm. I then loosened the injector line to cylinder 1 (red arrow in pic below), and the engine just about stalled and no fuel came out. I then loosened the line to cylinder 2 (yellow arrow), and started getting a steady pulsing of fuel coming out and the engine maintained rpm.

So it would appear that cylinder 1 is not getting any fuel pressure, yet by releasing line, the engine dies.

Any ideas?

 

[JC-jetro]

This is very puzzling , you have done it right. I do have the drain hole, fill hole and the level hole. In mine the oil amount for sure was 2 oz as I have done it at least 3 times since I bought the tractor. I see no relationship whatsoever between the oil in the injector pump and loosing the prime on injector #1. I'll try to bleed injector #1 after putting 2 oz oil in it. Low oil might damage the pump plungers. This indeed is strange. I'm curious if you actually completely drain out the oil by opening the back plate. On mine I do have a drain hole and I did not remove the back plate.

JC,

 

[pclausen]

Thanks JC. You confirmed that 2 oz is what I need. I'll add another 1.5 oz in the morning and do a full bleed.

Now, I did change the fuel filter, and did a bleed after that and ran the engine, and it would rev fine to redline. It was after that I did the fuel pressure pump oil change. Go figure...

 

[JC-jetro]

Thanks JC. You confirmed that 2 oz is what I need. I'll add another 1.5 oz in the morning and do a full bleed.

Now, I did change the fuel filter, and did a bleed after that and ran the engine, and it would rev fine to redline. It was after that I did the fuel pressure pump oil change. Go figure...

I'm not a betting man but I'll go ahead and bet you a $ that your Problem is air in the injector #1 caused by filter change. The fuel pulsation can squeeze the air bubble back and forth and not actually force the fuel out. Air is compressible where the diesel fuel is not.

JC,

 

[1980 F1500]

Did you disturb the throttle attachment on the pump when you removed the top fill cap? Maybe it is not attached, and that is why the engine speed won't change.

 

[JC-jetro]

Did you disturb the throttle attachment on the pump when you removed the top fill cap? Maybe it is not attached, and that is why the engine speed won't change.

That's a good point but he loosened the injector #1 connection and no fuel cam out where on#2 injector fuel pulsated out.

JC,

 

[1980 F1500]

You are absolutely right, of course. Very odd. I was wondering how he got it started on one cylinder and it is idling.

"Starts right up, but won't go past idle rpm. I then loosened the injector line to cylinder 1 (red arrow in pic below), and the engine just about stalled and no fuel came out. I then loosened the line to cylinder 2 (yellow arrow), and started getting a steady pulsing of fuel coming out and the engine maintained rpm."

 

[JC-jetro]

You are absolutely right, of course. Very odd. I was wondering how he got it started on one cylinder and it is idling.

"Starts right up, but won't go past idle rpm. I then loosened the injector line to cylinder 1 (red arrow in pic below), and the engine just about stalled and no fuel came out. I then loosened the line to cylinder 2 (yellow arrow), and started getting a steady pulsing of fuel coming out and the engine maintained rpm.right, of course. This very odd. I was wondering how he got it started on one cylinder and it was idling"

It is indeed odd. I think, probably he had both injector lines full of fuel. He changed the oil in the injector (had nothing to do with the fuel). He then changed the fuel filter. at that point he introduced some air in the filter area upstream of the the injector pump/plungers. He did then started the tractor and at that point it started right up as everything downstream of injector pump /plunger was good and no air. A bit more running and suction brought the air bubble in to the pump area and then pump started pulsating air rather than fuel and could not pump.

That's my story and I'm sticking to it

JC,

 

[1980 F1500]

Perfectly great explanation (story). You are da man on the 1700s. Been reading your posts for a while and you know your stuff. Hope the OP gets it figured out and lets us know the outcome.

 

[pclausen]

I worked on it some more this morning. I took both injectors apart and they looked good. I then cranked the engine over without the injectors and got steady fuel pulses on both lines. Put everything back together and same thing. It starts right up, but only idles at 650 (cycles from 600 to 700 at a steady rhythm). I let it run for about 10 minutes. I'm now able to loosen either injector line and get fuel streaming out without the engine dying.

I of course started by adding another 1.5 oz of oil, to bring the total to 2 oz.

Throttle attachment should be fine since the engine shuts down when the hand throttle is pushed all the way forward. I'll double check the linkage just to make sure.