Hard starting 2400H - lift pump failing?

[oldnslo]

Well tried the electric lift pump idea with no change in how it starts with cold engine.. so now really puzzled on what changed.

Received around 8” wet heavy snow Friday and ran fine while moving snow for over an hour. Did notice during this time that throttle would drift back to around 1700 RPM if set at any speed above 1700. Did not notice this when blowing snow earlier this winter. Will rev up to 2,600 at stay there as long as you hold the throttle. Suspect friction nut worked loose.

I did clean the injector pump before swapping feed pumps and saw no evidence of any fuel leaks.

 

[K5lwq]

My next step would be to remove the stop solenoid and see if that makes a difference. I doubt it will but I would try just to eliminate it. I see three wires going to it in your picture. So it has the pull and hold circuit. Maybe it is not pulling all the way back at first?

I suspect the friction nut needs adjusting as well.

 

[Zork]

My next step would be to remove the stop solenoid and see if that makes a difference. I doubt it will but I would try just to eliminate it. I see three wires going to it in your picture. So it has the pull and hold circuit. Maybe it is not pulling all the way back at first?

I suspect the friction nut needs adjusting as well.

Possibly. Check the throw of the lever as compared to the throw of the solenoid and go from there. If your ignition is damaged, it may be causing the problem where the pull in portion is not being de-energized. I would determine how the solenoid works while disconnected from the wiring harness using a fused jumper then you can eliminate it as the problem.

 

[ericm979]

Is the stop solenoid always either all on or all off, or can it be partially closed/open?

 

[Zork]

Is the stop solenoid always either all on or all off, or can it be partially closed/open?

I "believe" it is all open or all closed and our design should pull when energized. Or will push or pull in the opposite design of any spring tension. You could rotate the IP lever towards the seat and try starting and try the reverse if that doesn't work. Then once you see the movement parameters of the lever you will set the solenoid travel for on/off accordingly. Maybe someone here with the same model can make an observation regarding their own identical machine and give you more accurate and solid information.

 

[oldnslo]

I removed the stop solenoid assembly from the injector pump and it is pull to start spring out to stop. Since the hole in the IP is approx 1 1/8” diameter I made a cover to replace the solenoid. Made no difference in how it starts so another item eliminated.

I did tighten friction assembly on throttle linkage so it now stays where you set it.

Think I am going to wait till spring - summer when grass is growing so can run under load for a period of time and run a tank of fuel with injector cleaner through it then. This is on off chance the warm winter and limited use possible created a little algae or something.

Shouldn’t hurt anything and may get lucky and it helps

Thanks again for all helpful ideas.

 

[Zork]

Is the rod on the upper left fuel cut off or throttle? What is the lever circled in yellow? Where is your throttle connected?

 

[ptsg]

View attachment 859448View attachment 859449Is the rod on the upper left fuel cut off or throttle? What is the lever circled in yellow? Where is your throttle connected?

Most likely a manual shutoff lever.

 

[oldnslo]

Lever circled is manual fuel shut off. When I removed the stop solenoid I used a mirror to look through the mounting hole to observe the fuel shut off mechanism movement while operating that manual lever. Everything looked clean and moved freely from what I could see.

Upper left with linkage attached is throttle.

 

[Zork]

Lever circled is manual fuel shut off. When I removed the stop solenoid I used a mirror to look through the mounting hole to observe the fuel shut off mechanism movement while operating that manual lever. Everything looked clean and moved freely from what I could see.

Upper left with linkage attached is throttle.

The circled lever is where the solenoid connects?
Have you checked to see if the banjo bolt/bleeder has a fine mesh screen or a screen below the bolt? And the vertical fitting to the right if it originates from the same line?

I would highly recommend bypassing/replacing your filter with a clear automotive filter

 

[oldnslo]

Zork
The stop solenoid bolts directly to the end of the IP it is hidden behind the filter in the pictures. You can see the electrical connector above the filter next to intake hose.

No I did not remove the banjo bolt to check for screen.

 

[Zork]

Gotcha

 

[oldnslo]

Well finally got some of the stuff off the honey-do list so spent a little time on my list ;-) I pulled the glow plugs to verify they all glow cherry red in a similar time with battery charger connected to them. Did not check voltage of charger. All 3 plugs started to glow around 5 - 6 seconds and 1/2" up on tip was cherry red in 9 - 10 seconds so that certainly should eliminate a bad glow plug. Still stutters / misses when first starting but runs fine once going.
I purchased a Racor 120AT filter/water separator assembly but will have to make a mounting bracket to finish installing it.

the search for a solution continues.

 

[K5lwq]

Wow, this one is being a pain! I would have thought for sure you would have found a weak glow plug. I like the idea of upgrading the filter though.

 

[oldnslo]

I am also looking at using infrared heat gun to check exhaust manifold temps at start up to see if I Can detect a difference in exhaust temp on one of the cylinders. Problem is #2 is kind of hidden behind muffler so am still kicking around how to do this since shooting the main exhaust manifold body at that point is the junction for all three cylinders.

 

[Zork]

Wow, this one is being a pain! I would have thought for sure you would have found a weak glow plug. I like the idea of upgrading the filter though.

Yeah, IMO that filter assembly is suspect at best. I replaced mine early on for a clear horizontal auto fuel filter. Doesn't look snazzy but offers a clear visual indicator for water or lack of fuel.

 

[ptsg]

Wondering if the o-ring in the shutoff valve on the filter housing could be letting air in and cause of weird issues.

 

[K5lwq]

I am also looking at using infrared heat gun to check exhaust manifold temps at start up to see if I Can detect a difference in exhaust temp on one of the cylinders. Problem is #2 is kind of hidden behind muffler so am still kicking around how to do this since shooting the main exhaust manifold body at that point is the junction for all three cylinders.

Maybe loosen the fuel line at the injectors one at a time to see if problem stays the same or gets worse?

 

[oldnslo]

Tried infrared gun and cylinder 2 exhaust manifold warmed up slower than 1 & 3. Still plan on replacing filter but if was air leak why would it seem to only affect one cylinder more than others?

The search for solution continues.

 

[K5lwq]

I think you are close to finding the problem. Next step for me would be pulling that number 2 injector and having it tested/rebuilt.