bezerk injection pump

[greg lousy]

I'm looking for injection pump advice but I'll give the back story because I think its relevant.

The pick up had been running well for a few weeks and today I tried running on Vegetable oil for the first time in about 10 months. I switched to the veg manually, with ball valves, in a way I've done in the past with no problems.

It kept running, but quickly started to lose power. I figured it was probably an air leak or air in the line, so I pulled over, killed the engine and switched back to diesel.

I started back up, and the revs maxed out right away - like I was 100% flooring it in neutral. Unbelievable clouds of thick white smoke from the exhaust, billowing - quite a roadside scene. (exhaust previously looked pretty clean) Engine shut off normally. Throttle not stuck.

As I was tooling around I noticed that part of the rubber veg line had degraded - to the point that there may have been loose pieces inside the line - conveniently - just after the filter. Also, the veg line had been sitting for months and now I'm wondering about crud.

Now I'm thinking that the engine may have been struggling when I switched to veg because the IP was struggling to suck in some piece of debris.

could something jammed in the injection pump cause these symptoms? maybe one of the injector ports is jammed open. Is there another place where a blockage could cause this?

open to any ideas, I need help - could I do some kind of backflush?

[TylerDurden]

I'd pull it and take the top off; flush it with brake parts cleaner & blow that sucker out good, so I know there isn't any crap jamming up the linkage or guts.

[Fatmobile]

Veg oil that has sat for 10 months can get chunky.
Air in the filter would help it.

[greg lousy]

Veg oil that has sat for 10 months can get chunky.
Air in the filter would help it

.

I knew I should work on the veg system before trying this. drain the tank, reprocess, flush the lines. But i didn't - total error in judgement.

I've been doing some IP homework. It's leading me to think the control collar is stuck in the wide open position. If it wasn't for the fact that the problem occurred right when I switched to my possibly dirty veg line, I would think that the something in the linkage broke or jammed - (a break in the linkage would cause the plunger to remain in the closed (idle) position - right?).

I'll probably start messing around with this sunday or monday - try flushing it in a few ways.

I'd pull it and take the top off; flush it with brake parts cleaner & blow that sucker out good, so I know there isn't any crap jamming up the linkage or guts.

would I get a better flush with the top off? I know its a lot and i have a long way to go in understanding the IP.

These are some of my thoughts but like I said, I'm open to any guidance before I start work - I'm not even sure these are the right questions. Also, if the control sleeve is in fact jammed, could I do anything productive by agitating the plunger? Are there any other places where a jam may cause my symptoms - delivery valve maybe?.

[vanbcguy]

Definitely not delivery valves - they don't come in to play in this case. The collar is the only part of the pump that has any control over fuel volume, or any ability to "stick" and cause something like this.

If you have a vacuum pump (or a pressure pump capable of pushing fuel for that matter), you could try purging whatever fuel is in the pump and refilling with automatic transmission fluid or diesel purge and then let it sit for a day or two. I'd then attempt to restart with a normal banjo bolt in place of the "OUT" bolt to allow any larger chunks to exit the pump. Once purged, put the proper "OUT" bolt back in again so your timing advance will work.

Opening up the pump will probably yield the fastest result but has the highest chance of messing something up. Trying a soak and purge first will eat up a few days, and might not work, but you might end up ahead of the game. If I didn't have an urgent need to have my car going by the next day I'd do the soak first. The pump can probably use it either way.

[TylerDurden]

... The collar is the only part of the pump that has any control over fuel volume, or any ability to "stick" and cause something like this.

AIUI, the control-collar is the working bit, but the other bits that control the control-collar could be stuck.

SmokeDiagram1.png

[air-cooled or diesel]

2 cans of lubro-moly run straight let it soak in for a day or two after running a can and run the second can after soaking. fresh fuel and fuel filter too. new fuel line(s), check air filter, can even add a can of lubro to full tank of fresh fuel (or oil) if it mixes w/oil. certainly can add a can to diesel and run thru, after running straight.

[greg lousy]

I've ordered lubro moly before - do any major parts stores stock the stuff? I've looked in a few with no luck.

I've got the plan, but not the juice - also - any opinions about gum turpentine? thinking it might be good, especially if the blockage is vegetable oil based..

[TylerDurden]

Many NAPA stores carry DP.

If you cant find it, you might be able to use naptha from the paint supplies store.

[air-cooled or diesel]

napa has it as far as i know.

[greg lousy]

Found it at Advance Auto Parts (Napa was closed sunday) - its in the IP now, hopefully working some magic.

[greg lousy]

four days soak - IP still crazy

I just took it apart and things are more messed up than I thought. On the bottom most part of the governor lever linkage there is a little sleeve that rocks back and forth, holding that nob that goes into the control collar and moves it. (the little part sticking into the yellow in Tyler's diagram).
I don't know how, but the metal on this sleeve was ripped most of the way through, and the little nub was loose in the pump.

I think I'm looking at a new pump. It looks like you could probably replace the governor spring assembly and I may get a junk pump and tool around with it, but to me that sounds like a better side project than something I need to do to get my only vehicle running. Also, I'm pretty sure I lost track of where everything goes. A lot of parts are held in place by the pump housing itself, and once I got the injector line side of the pump off, things got a bit out of hand quickly. My advice to anyone taking their IP apart and putting it back together would be to go very slowly and carefully once they get to this part.

thanks for the help.

[TylerDurden]

Bummer (and a bit bizarre), but not total disaster... the info on re-assembly here is pretty good and you might find a replacement part from another board member.

It might also be re-assuring to know that the WVO system probably had no bearing on the IP failure.

I'd love to see a pic of that torn sleeve.

[82vdub]

Here's a thread on how to rebuild these pumps.

http://www.greenbaypartsworld.com/vw/vw ... ebuild.htm

[greg lousy]

Thanks 82Vdub, thats a great thread and may come in handy.

well here it is. sorry the pictures are a little blurry. The white looking line in the first one is the tear, thats the exposed metal. The little hole in the sleeve is where the little nub in the second photo was seated, extending down to the control collar. This is the bottom most part of the linkage (the bottom of the green part of Tyler's diagram, with the little nub extending into the yellow)