[scout4bta]

Bought this engine many years ago for another project. Now it's going into the Wagoneer if someone can resolve the problem.
It's a 130hp P pump, stock, came out of a FrieghtLiner MT35. Replaced the injectors for a no load mid speed miss, that did not
resolve the problem. Timing is stock. I did put in the 3200 GSK.
It starts easy. After about 1/3 throttle it starts to miss and blow white smoke and flames out the exhaust.

https://flic.kr/p/2naD24w
edit:
Compression was right around 400 psi for all cylinders.
Replaced the IP overflow valve, just in case.

 

[char1355]

Scout, have you checked the pump timing? It may have slipped. White smoke is unburned fuel due to lack of heat. You've got good compression so that's not the issue. Checking the timing is simple. Just rotate the engine to TDC and lock the cam pin there below the injection pump. Then unscrew that little cap on the side of the pump and there's a little tool in there used to check timing. Here's a very good video on that procedure.

You mention replacing the injectors. Are they the correct pop pressure for a P pump? If they happened to be lower pop pressure that too would affect timing. If you find the pump timing is off, you can fix that without removing the front gear cover. You just work through that hole in the cover where the injection pump nut is. Main thing is that pump shaft and gear must be totally free of any oil. Use brake cleaner to be sure. Once you gently snug the nut you be sure and release the cam pin and remove the little tool from the pump before you torque that nut.

 

[scout4bta]

Scout, have you checked the pump timing? It may have slipped. White smoke is unburned fuel due to lack of heat. You've got good compression so that's not the issue. Checking the timing is simple. Just rotate the engine to TDC and lock the cam pin there below the injection pump. Then unscrew that little cap on the side of the pump and there's a little tool in there used to check timing. Here's a very good video on that procedure.

You mention replacing the injectors. Are they the correct pop pressure for a P pump? If they happened to be lower pop pressure that too would affect timing. If you find the pump timing is off, you can fix that without removing the front gear cover. You just work through that hole in the cover where the injection pump nut is. Main thing is that pump shaft and gear must be totally free of any oil. Use brake cleaner to be sure. Once you gently snug the nut you be sure and release the cam pin and remove the little tool from the pump before you torque that nut.

Charr1255,
Checked the timing 3 times, it's right on the money. The injectors are correct, got them from Perkins Diesel Service, Sent them my old ones, I trust them to send me the correct ones back. I had thoughts that one or more injectors had low pop pressure, but the "new" injectors did not fix the problem.
I'm beginning to believe the problem is internal to the pump, unless someone has a external cure.
And then there's this problem.

 

[irhunter]

Fuel delivery? Before I sent the pump off, I'd add a pressure gauge right before the IP.

 

[scout4bta]

Fuel delivery? Before I sent the pump off, I'd add a pressure gauge right before the IP.

Yes forgot to mention that. Pumping the lift pump brought it right up to 24 psi, then the overflow valve would open. Ran the engine and with out a snubber valve to the gauge it fluctuated to wildly. I think I saw the guage read between 22 and 15 psi. Replaced the overflow valve a month ago.

 

[char1355]

Did some reading and found others with similar issues. Main culprits were late timing which you pretty much ruled out, low fuel pressure, and air in the fuel. Other areas that could affect it are the overflow valve which you changed and a bad delivery valve in the injection pump. Might check all you hose fittings to be sure all are tight. Might install a short section of clear fuel hose just before the lift pump to be sure you're not sucking air from the tank. Also, be sure your tank vent is working. On the fuel pressure the factory settings are 17-22 PSI at idle and 25-35 PSI @ 2500 RPM with no load. When you installed the new overflow valve was it a Bosch unit or an aftermarket type. Also, did you install new sealing washers. On the lift pump there is a filter screen that can become clogged. See photo below. Just trying to think of all the little stuff short of pulling the pump off to have it checked.

 

[scout4bta]

Did some reading and fund others with similar issues. Main culprits were late timing which you pretty much ruled out, low fuel pressure, and air in the fuel. Other areas that could affect it are the overflow valve which you changed and a bad delivery valve in the injection pump. Might check all you hose fittings to be sure all are tight. Might install a short section of clear fuel hose just before the lift pump to be sure you're not sucking air from the tank. Also, be sure your tank vent is working. On the fuel pressure the factory settings are 17-22 PSI at idle and 25-35 PSI @ 2500 RPM with no load. When you installed the new overflow valve was it a Bosch unit or an aftermarket type. Also, did you install new sealing washers. On the lift pump there is a filter screen that can become clogged. See photo below. Just trying to think of all the little stuff short of pulling the pump off to have it checked.

To check Delivery valves, I think that requires a splined socket which I don't have.
My "tank" is 2 gal oil jug now filled with Diesel, setting next to the engine.
Will check the filter screen on the lift pump.

 

[eggman918]

To check Delivery valves, I think that requires a splined socket which I don't have.
My "tank" is 2 gal oil jug now filled with Diesel, setting next to the engine.
Will check the filter screen on the lift pump.

I have the socket and can mail it to you as long as you send it back when finished with it.

 

[Blackduck596]

Is the return line submerged in the jug to prevent aeration of the fuel?
And bubbles in the return fuel.
Is the suction line clear of the bottom of the jug?

 

[scout4bta]

I have the socket and can mail it to you as long as you send it back when finished with it.

Thanks Steve, but I don't feel up to taking the Delivery valves out, at least not right now.

Charr, The filter screen was clean.

 

[scout4bta]

Is the return line submerged in the jug to prevent aeration of the fuel?
And bubbles in the return fuel.
Is the suction line clear of the bottom of the jug?

The return line is submerged, no air bubbles. I used a clear container to check for air bubbles.
The suction line is at the bottom and has 2 bevels on the end so it can't be block (arrow head)

 

[irhunter]

Yes forgot to mention that. Pumping the lift pump brought it right up to 24 psi, then the overflow valve would open. Ran the engine and with out a snubber valve to the gauge it fluctuated to wildly. I think I saw the guage read between 22 and 15 psi. Replaced the overflow valve a month ago.

You got a fuel pressure reading when the motor is at the 1/3rd throttle...when it stumbles?

 

[scout4bta]

You got a fuel pressure reading when the motor is at the 1/3rd throttle...when it stumbles?

Good question. I'll have to put it back on and check.

 

[edpruss]

Is the return line submerged in the jug to prevent aeration of the fuel?
And bubbles in the return fuel.
Is the suction line clear of the bottom of the jug?

I always screw an appropriate size nut on the end of a hose to weight it down and keep it there.

Ed in CO

 

[Blackduck596]

Was there miss there before changing the governor springs?

 

[scout4bta]

Was there miss there before changing the governor springs?

At that time the engine was sitting on a cradle, not bolted down. Any revs much past idle would cause the engine to try and jump off the cradle.
That's what prompted me to build the run in stand with the rubber isolators so I could validate that the engine/IP were in good shape.
The governor spring install was an easy job so I don't think there was any problems with it.
edit:
To answer your question, don't know.

 

[char1355]

Sort of running out of ideas. Have you made any change to the torque plate in the pump?

 

[scout4bta]

Sort of running out of ideas. Have you made any change to the torque plate in the pump?

No I have not made any changes to the torque plate nor do I plan to. Other than the governor springs it's going to remain "stock".

 

[scout4bta]

You got a fuel pressure reading when the motor is at the 1/3rd throttle...when it stumbles?

The fuel fuel pressure gauge reads 20-26psi when the engine begins to stumble.

 

[scout4bta]

Monday I ship the IP off to Perkins Diesel Service.
Thanks to the members who offered help on this mysterious problem.