Another bubbles in the fuel line thread

awitty

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Equipment
d1150 & d950
Oct 11, 2021
34
2
8
uk
Hi

I could do with some advice in identifying a fuel issue with an old d1105 3 cylinder that I’m trying to resurrect.

The engine won’t start and at present I’m seeing lots of air in the overflow pipe that connects the injection pump to the injector overflow line. Whilst I’m cranking the engine the air bubbles disappear, but once I stop cranking the overflow fills with air as though there is some kind of suction force taking place as the crank slows down. Is there an explanation for this?



So far I’ve tried;

Changing the fuel lines.​
Bypassing the fuel filter and tank by hanging an IV type bottle above the engine.​
Re-seating the injectors.​
Using an alternative (Electric) fuel pump​


I did remove the starter solenoid and bleeder housing. Could a bad gasket on either of these cause the issue?

I've also replaced the injectors (sourced from a reliable supplier - not ebay!)



Any help or pointers would be appreciated. I’m running out of ideas.
 

Roadworthy

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L2501 HST
Aug 17, 2019
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Did you bleed the air off the fuel lines prior to the injection pump according to the manual? If so you should not be picking up air there. I would probably remove the injectors and take them to a local shop capable of rebuilding them. They should be able to check the injectors and see if one is not seating correctly allowing air from the cylinder to blow past on compression. That's just a guess. Perhaps others will add their own.
 

GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
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bad head gasket ?
fuel line connection not 100% tight ?
Have no direct knowledge of that engine or what it's in, but generally speaking...air bubbles in fuel lines comes from sucking air in.
the bubbles 'disappear' , maybe because they're too small for you to see, while cranking the engine ??
someone who KNOWS that engine ( tore one apart), may know 'what ain't tight' that's allowing air to be sucked in.
 

kubotafreak

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GRAND l6060, L3560, B6100, gr2100, tg 1860, g1800, g1900, g2160
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Is there any smoke out of the exhaust while cranking? Black, White? Does the engine ever jump like a cylinder is catching? If no smoke at all I would suspect the injection pump rack is stuck.
 

mendonsy

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B7500HST/LA302
May 28, 2012
339
19
18
Mendon, NY
My B7500 has the D1005 engine which is similar to the D1105. I had a problem several years ago with a very small split in the return line from the injectors which was causing the injector pump to draw air.
That split was almost invisible and was very difficult to find. I just happened to notice a small spot of fuel on the side of the return line or I would not have seen it.
 

awitty

Member

Equipment
d1150 & d950
Oct 11, 2021
34
2
8
uk
Is there any smoke out of the exhaust while cranking? Black, White? Does the engine ever jump like a cylinder is catching? If no smoke at all I would suspect the injection pump rack is stuck.
Generally white smoke and I think one of the cylinders is catching. Don't think the rack is stuck. I've had the fuel lines off the pump and can see them shooting fuel
 

awitty

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d1150 & d950
Oct 11, 2021
34
2
8
uk
Thanks for all the comments. Still no joy. I'll probably upload a video and see if anyone can spot something.
 

Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
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I've had the fuel lines off the pump and can see them shooting fuel
This may be the problem!
There is something underneath that connection point in the injection pump that adjusts the fuel delivery and is easily maladjusted if not properly held at the large nut below the injection line.

I’ll find a thread that discussed it with good detail and link it here
 
Last edited:

D2Cat

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I think Russell has described the problem. Those are delivery valves and have to be very careful.
There are some small components that are critical for fuel delivery. If you want to check fuel delivery from an IP go to the injectors and loosen the line there, in older engines.
 

kubotafreak

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GRAND l6060, L3560, B6100, gr2100, tg 1860, g1800, g1900, g2160
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Sounds like a compression check is in order... White smoke present is unburned fuel, so injection is trying. May check the valve lash to make sure you have some clearance. Does the glow system work?