Perkins air in fuel

[doxford jim]

Fuel injector return lines ? Any signs of fuel around the heads from fuel lines?

 

[GManBart]

It is possible. That lift pump is not the most robust. It may be possible that the FIP has enough draw at full speed to draw enough fuel to run at but at lower speed it needs help. Grasping at straws here. I think the same lift pump was used, and possibly is still used on unregulated engines, across the board. The only way I know to test for sure is to replace but dealer mechanic may have advice.

That makes some sense. For all of $26.02 I ordered a new lift pump today...figured it's worth a shot. I'm still going to disconnect the fuel supply from the tank to the lift pump, and see what that looks like first. I can't see where the outlet is inside the tank, but the areas of the tank I can see with a super bright flashlight look extremely clean.

 

[GManBart]

Fuel injector return lines ? Any signs of fuel around the heads from fuel lines?

I looked at the return lines more closely tonight, but didn't see any signs of fuel coming from them. Granted, I had already tried bleeding the lines by loosening the injector fittings, so there was fuel all over the general area, and I could have missed something. Before I loosened the injector fittings the entire area was dry, and free of fuel.

 

[Oldtractorfixer]

Problem is probably at or before the lift pump. After the pump it should all be under pressure and would leak not suck air. Before the pump is the vacuum side which can pull in air. Will not necessarily leak fuel. A restriction pre-pump can create a high vacuum in the suction line making an air leak more likely.
Good luck.

 

[GManBart]

Problem is probably at or before the lift pump. After the pump it should all be under pressure and would leak not suck air. Before the pump is the vacuum side which can pull in air. Will not necessarily leak fuel. A restriction pre-pump can create a high vacuum in the suction line making an air leak more likely.
Good luck.

That makes perfect sense....thanks. I'll start with the line from the tank to the lift pump, and see what the flow looks like next. I'm not terrible worried at this point, but it was kind of funny when my wife said "maybe your second tractor should be a new tractor too?" last night....gotta love that woman!

 

[sd455dan]

That makes perfect sense....thanks. I'll start with the line from the tank to the lift pump, and see what the flow looks like next. I'm not terrible worried at this point, but it was kind of funny when my wife said "maybe your second tractor should be a new tractor too?" last night....gotta love that woman!

If the fuel system proves to have good volume from the tank,

Had a somewhat similar problem on Leyland 344, the person that worked on it before me replaced the fuel filters , the old filters were dirty for sure , the system could be primed up and the tractor would start and run for a bit and then die. figured it needed a new pump- the linkage on the pump was very worn -installed it and went on to the new filters- in the end it was a small leak on the installation of the o ring/ filter housing allowing air to be drawn in.

When trouble shooting, we found the filters were virtually empty.

The weird thing was that this tractor had the fuel tank mounted ABOVE the engine- but it was level with the filter housings... and with a leak at the filter housings the injector pump would empty the filters even with a a full tank of fuel and a brand new lift pump. This was a CAV injection system and the engine was BMC. Not sure if the Perkins is the same.

Good Luck- I'm sure you will get it running well

 

[GManBart]

If the fuel system proves to have good volume from the tank,

Had a somewhat similar problem on Leyland 344, the person that worked on it before me replaced the fuel filters , the old filters were dirty for sure , the system could be primed up and the tractor would start and run for a bit and then die. figured it needed a new pump- the linkage on the pump was very worn -installed it and went on to the new filters- in the end it was a small leak on the installation of the o ring/ filter housing allowing air to be drawn in.

When trouble shooting, we found the filters were virtually empty.

The weird thing was that this tractor had the fuel tank mounted ABOVE the engine- but it was level with the filter housings... and with a leak at the filter housings the injector pump would empty the filters even with a a full tank of fuel and a brand new lift pump. This was a CAV injection system and the engine was BMC. Not sure if the Perkins is the same.

Good Luck- I'm sure you will get it running well

That's good stuff...thanks!

 

[GManBart]

Disconnected the input fitting from the tank at the lift pump tonight and it seemed to be perfect fuel flow....solid, steady, no sign of bubbles. I guess I just wait for the new pump to get here

 

[D7E]

Lift pump probably . Have had similar problems on combines with 6cyl perkins engines and filter heads that hold the filter have been to blame .

 

[GManBart]

Lift pump probably . Have had similar problems on combines with 6cyl perkins engines and filter heads that hold the filter have been to blame .

Well, I have a new lift pump on the way, and I put a brand new filter assembly (with new head) on it the other day. If the lift pump doesn't fix things, I'm going to take the new filter head off, and put the old one back on, with the new seals, to see what happens.