Forum for air cooled diesel engines and clones

[KangerooL48]

Thanks for your prompt responce. I have been editing my initial post to correct any errors and add some additional information I had missed.

Down in the South west of Western Australia

Pump is a “Pumps of Australia” unit. Not exactly sure the name plate identification is difficult to read approximately 400 litres a minute.

Yes high pressure fuel pump with integrated stop solenoid .

Pump motor “starts” easily however wont run up to speed without a shot of WD40. Once up to speed it’s fine you can reduce speed to approximately 1/4 throttle no problem and back up to full throttle ok. Unfortunately from low idle just doesn’t want to build up speed?

Can post image when I update post

 

[ponytug]

Thanks for your prompt responce. I have been editing my post to correct any errors and add any information I had missed.

Down in the South west of Western Australia

Pump is a “Pumps of Australia” unit. Not exactly sure the name plate identification is difficult to read approximately 400 litres a minute.
Yes high pressure fuel pump with integrated stop solenoid .

Pump “starts” easily however wont run up to speed without a shot of WD40. Once up to speed it’s fine you can reduce speed to approximately 1/4 throttle no problem and back up to full throttle ok. Unfortunately from low idle just doesn’t want to build up speed?

Can post image when I update post

My bet is on a defective seal around the solenoid to injection pump. I suspect that there's just enough air to prevent building speed due to the inefficacy of the the injection pump with air in the high pressure line, but once the engine is at speed, the fuel velocity is enough to sweep the air through, with minimal impact on the pressure. I think that these Yanmar engines are great motors, but these really have trouble with any amount of air in the diesel.

Pumps of Australia has some nice units; I just wish that the exported them here; I tripped across them when looking for a pump for high pressure fire fighting. I have a slightly more powerful two stage version, but with a gasoline (petrol) engine as there is very little interest here in small diesels (noise, fuel, air quality). If I find an L100, I might swap it in at a future date.

If bleeding the line doesn't solve the issue, I would go ahead and buy a replacement solenoid injection pump. FWIW: I keep spare injection pumps as part of my spares kit, as when I need mine to work, it has to work.

All the best,

Peter

 

[KangerooL48]

Checked fuel pump rack engagement with forked lever was correct. Loosened throttle plate to properly check govenor springs position and levers. Seems Ok. Bleed system. Unfortunately still same problem.

Edit to add. Checked service manual one spring not in the position suggested. Although I noted that one lever only had one hole to select and changed other end of the spring onto the middle position on the other lever. Will test again tomorrow as I had sikaflexed some fuel hose into position to hold the various electrical wiring harness securely in position and I had to wait for that to set overnight.

I also noticed when I had fuel pump removed I checked the fuel pump cam follower which seemed ok but noticed slight pitting on the low area on one side of the fuel pump cam. Measured pump shim thickness 0.4 mm.

Will order a new pump and a few other bits and pieces. Any leads regarding a reliable quality supply source? I generally use Temu or Aliexpress however open to other suppliers.

 

[ponytug]

Checked fuel pump rack engagement with forked lever was correct. Loosened throttle plate to properly check govenor springs position and levers. Seems Ok. Bleed system. Unfortunately still same problem.

Edit to add. Checked service manual one spring not in the position suggested. Although I noted that one lever only had one hole to select and changed other end of the spring onto the middle position on the other lever. Will test again tomorrow as I had sikaflexed some fuel hose into position to hold the various electrical wiring harness securely in position and I had to wait for that to set overnight.

I also noticed when I had fuel pump removed I checked the fuel pump cam follower which seemed ok but noticed slight pitting on the low area on one side of the fuel pump cam. Measured pump shim thickness 0.4 mm.

Will order a new pump and a few other bits and pieces. Any leads regarding a reliable quality supply source? I generally use Temu or Aliexpress however open to other suppliers.

I tend to use nylon pull ties (zip ties) to hold things in position; I make too many mistakes for glue.

I would have to go check on the spring position(s). It isn't something I have dealt with in the past. My recollection is that those modulated the governor response.

Here, I order from Amazon/ebay/Yanmar, and I have had occasional low quality parts turn up from the non-Yanmar sources.

Nice set up!

All the best,

Peter

 

[KangerooL48]

“I tend to use nylon pull ties (zip ties) to hold things in position; I make to many mistakes for glue.”

I usually do the same. However there is a drip tray that the motor and pump sit on/in. Didn’t want to drill through this to secure wiring harness. Using the correct sized fuel hose with a cut that allows me to remove harness if/when I need to. In effect a flexible saddle ! Cheers

 

[ponytug]

“I tend to use nylon pull ties (zip ties) to hold things in position; I make to many mistakes for glue.”

I usually do the same. However there is a drip tray that the motor and pump sit on/in. Didn’t want to drill through this to secure wiring harness. Using the correct sized fuel hose with a cut that allows me to remove harness if/when I need to. Cheers

Aaaah. I now understand what you did. Brilliant!

All the best,

Peter