Advice on problem with Stanadyne fuel cutoff linkage.

[olddesertrat]

Been awhile since been here. Have 1985 F350 6.9L duelly. Been parked for 8 years. Ran great when parked. Now will not start. Did all usually stuff: fresh fuel, changed filters, ect.
Tracked issue down to injection pump not pumping fuel to injectors. Took off top of Stanadyne DB2 injection pump.
Found problem with cutoff linkage. With no power to solenoid, linkage is pushed towards driver and fuel is cut off.
When powered the solenoid moves towards radiator and linkage is suppose to also toward radiator. That does not happen. Linkage stays pushed towards driver, in off position.
Saw YouTube video of my exact problem. Video says if injection pump goes dry or sits long time, linkage may stick. In video problem solved by just manually pushing linkage back and forth a few times. That does not work on my stanadyne DB2. Do not feel any sticking or roughness as linkage moves. Guessing there is suppose to be some spring tension that moves linkage to 'fuel on' position when solenoid is activated. That spring tension is just not there.
This injector pump was a full rebuild replaced 2 years before parking F350. Worked great for those 2 years and should have decades of life still in it.
Any advice on what could be wrong with linkage and how to fix it?

 

[Clb]

Are you sure it was getting 12v?
Is the pull coil good?

 

[olddesertrat]

yes, electrical is good. With VOM get 12vdc at solenoid connector with key on.
Disconnect power wire, turn key on, then touch/remove power wire to solenoid lead, can hear solenoid click on/off.
Remove top on injection pump, connect ground wire to to case, repeat above, can see arm on solenoid move back and forth like it should.
Solenoid looks new. Likely was replaced when when injection pump rebuilt.

 

[IDIBOBS]

This is why diesels are not supposed to sit. I’d bet its varnished or gummed up. Time to pull and clean

 

[olddesertrat]

Here is link to YouTube Video:

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In video when black tab is pushed to fuel closed position(top of screen), when finger is removed, it pops back to open position strong and fast. Mine does not.
IDIBOBS: You could be right. Was thinking of that too. Had drained old fuel out of pump, sprayed linkage with Blaster PB, let sit, filled with fresh diesel, drained, filled again.
Made no change. If problem is varnish/gum up deep inside pump, is cleaning something I could do with standard tools?

 

[IDIBRONCO]

Maybe try some ATF overnight?

 

[IDIBRONCO]

Been awhile since been here.

Yes it has, but you're still welcome!

 

[olddesertrat]

IDIBronco: After reading your reply read up on ATF for cleaning diesel fuel systems. Most comments are about keeping injector pump and injectors clean by adding ATF to fuel tank on running vehicles. Seems safe for old mechanical injectors.
Then saw comment on Seafoam injector cleaner dissolving tars and varnished in injector pump and injectors.
As Seafoam is specially made as fuel system tar/varnish cleaner was wondering pouring bottle of Seafoam injector cleaner directly into injector pump and letting sit overnight may be a better cleaner than ATF. What are your thoughts?

 

[IDIBRONCO]

IDIBronco: After reading your reply read up on ATF for cleaning diesel fuel systems. Most comments are about keeping injector pump and injectors clean by adding ATF to fuel tank on running vehicles. Seems safe for old mechanical injectors.
Then saw comment on Seafoam injector cleaner dissolving tars and varnished in injector pump and injectors.
As Seafoam is specially made as fuel system tar/varnish cleaner was wondering pouring bottle of Seafoam injector cleaner directly into injector pump and letting sit overnight may be a better cleaner than ATF. What are your thoughts?

I don't know which would be better/stronger. Most people use ATF, but I don't see why Sea Foam wouldn't work either. Either way, if it doesn't help, you're only out a few dollars.

 

[olddesertrat]

The 24 hour Seafoam soak Sunday worked wonders. Fuel cutoff linkage spring returns to fuel open position fast and strong. However will still have to remove injector pump.
Case of Mechanics Bad Luck.
Mechanic's Good Luck is when you drop a nut while working, it is caught by clothe under bolt or lands flatly on nearest flat surface.
Mechanic's Bad Luck is when nut does and bounce or two, then flies down a dark, greasy black hole to never be seen again
That happened with small spring at end of throttle shaft, The little spring that contacts the 'L' bend in cutoff linkage nearest radiator.
While looking/probing linkage, hand slipped, popped off spring...and watched spring just disappear. Fell is exactly the right way to travel all the way down to bottom of pump.
Since the drive shaft and lots of other moving parts are down there decided it would NOT be a good idea to turn over truck until spring is removed. Have tried digging around with paper clip with hook on end. No luck. Hoping if disconnected, can turn pump upside down and shake it out.
One last note: After 24 hour soak in Seafoam, some of iron parts in injection pump, like the throttle shaft, started to show light rust marks. am certain those were not there before.
May be something in undiluted Seafoam the oxidizes, or rusts iron.
Thanks for the help on suggestions. The original problem that started this thread is solved.

 

[IDIBRONCO]

Glad to hear that you're making progress even if the spring feels like a step backward.

 

[olddesertrat]

Have not pulled pump yet...was 108 degrees yesterday. Tried magnet on extendable stick to get spring in pump...too rigid. Anybody heard of magnet on end of flexible cable, like magnet on end of guitar string? Something like that may be able to reach sunken spring.

 

[olddesertrat]

Found this mini flexible magnetic pickup on Amazon. Lisle 66540.
It was just what I needed and most important, it worked!!
Was able to fish spring out of injection pump without taking apart.
Saved a whole lot of work.