Spare Injection Pump has Super Fast Idle

[orbitald]

Hi,

I removed my injection pump because it had too much play in the main shaft and yesterday I installed a spare pump 068130109H with an unknown history. It had sat for a couple of years on the shelf so I cycled a can of diesel purge though it on the bench and then another half liter of diesel to clean it out before installing in on my AAZ TD.

The good news is that it starts. The bad news is that it goes into a super fast idle immediately upon start up. It races so fast I have to kill the power immediately after starting otherwise it feels like it would run away and blow up.

This pump still has the factory seal on both the residual fuel screw and the max fuel screw. I adjusted the minimum idle stop and the idle screw all the way out and its still racing upon start up. Could there be something stuck inside that I can check?

Thanks,

David R.
Oakland CA

[ORCoaster]

Could the throttle inside the pump be hung?  You might just have to crack that seal on the Max fuel screw and bring it down a few turns.  It may just be holding the idle up. 

[Gizmoman]

Have you checked the FAQ?
Lots of good info there
http://www.vwdiesel.net/forum/index.php?topic=16687.msg118139#msg118139

[Toby]

Most likely you have gelled fuel mucking up the innards of your IP. I have never found anything that will de-slime one. I have tried Diesel Purge, Marvel Mystery Oil, ATF, Kroil, mineral spirits, and anything else that I could think of. Even carb cleaner. When you go to clean out such a slimed up IP, I suspect you will find it is full of gunk that reminds me of cosmoline. About that consistency and color, about that hard to remove. I suspect that it is gelled up biodiesel which has largely replaced the lube oil in diesel fuel.

If you have ever been inside one of the pumps, its no big deal to clean them out. You just have to be METICULOUSLY clean. Any foreign matter will damage the pump and go through the injectors as well. Even dandruff falling out of your hair as you work. Its easy to waste a good pump, if you are ham handed. You can't do IP wwork in a typical garage and expect the IP to last very long. On the dining room table would be best. After establishing a "sterile field" of newspaper to work on. A homebrew clean room is what you are trying to achieve.

FWIW, It is not possible to wipe down anything that goes inside the pump w/o transferring lint and other trash to the part. It is much better to hose each piece down with Brakleen as you install it. That is kind of hard to do on the kitchen table if the women are anywhere around, though. ;<)

[orbitald]

Thanks Folks!

I tried moving the max fuel screw around and didn't have any luck so I removed the top of the LDA and it looks a little mucky on one side.





Looking at this diagram it looks like the Control Sleeve could be stuck:





The control sleeve is what meters the fuel and I believe its controlled by the governor:





I'll try and pull the top off the pump tomorrow and see whats going on.

[745 turbogreasel]

It takes very little goo to stick the #7 control spool.

[Gizmoman]

I wonder of heated diesel or MMO would un-stick it. No idea how you would do that safely but I think if the "goo" were warmed up considerably, it may let loose.

[ORCoaster]

That collar is on there so tightly anyway if you don't have a little diesel or lube on it, it can be hard to slide at all.  I have personally dealt with this situation and the only way I had success was to tear it apart.  I never had a long term soak though.  Just didn't have the time to spare for such a thing.  I bet you will find the vane pump to have a similar sticky parts to the four flappers.  They have about the same amount of clearance as this collar. 

Boiling ATF inside and soak it, maybe? 

[TylerDurden]

One only needs to take the top off to check it, right?

[orbitald]

Here is a photo of the underside of the top cover:



This shows a little gunk under the lid. I did notice that the guide pin (4) that rides along the control cone (9-boost pin) was quite sticky. Could that cause the racing condition? I'm thinking it could give a max fuel situation if it was stick out, away from the boost pin.



And one from the top down inside the pump which overall looks very clean.



Any ideas what else could keep the idle so high.

[burn_your_money]

Since you have the top off, manually move the control lever assembly and see if the collar is moving or not.

[orbitald]

Yep, the collar moves easily and smoothly. 

I worked the guide pin (4) alternating ETOH and light oil and it seems to be working much better although it is still the slightest bit sticky. I'm not exactly sure how to remove the pivot rod (M1) for the stop lever (3) but I removed the screws on each end and I'll try pressing it out tomorrow. That will give me access to the underside of the top which still has some much deep in there. I can also remove the guide pin and clean it up.

Also, the wings / weights on the governor don't move out. It seems they are locked some way. I'm guessing its designed that way but I'm not sure.

[8v-of-fury]

They don't move at all from this position??

[orbitald]

No, they don't move. I thought I would be able to spread the out and the center pin would push out but they seemed locked in there. Perhaps I need to push them all at once?

Or perhaps that is the problem...

[ORCoaster]

You have to get the front shaft to turn and those weights will move out like little doors once the mechanism gets to turning.  That will allow the rod to move as well.  At stationary position yes they do kind of lock it down.