pump question

[paccool]

Need a little help here. Tonight I pulled the top off the pump and rotated the cone about 90 degrees. Didn't seem to help a lot so will turn it some more tomorrow night. Question - When I pulled the cone out of the hole, a small amount of oil comes out the top of the bore as the cone is pulled out. It looks like it just runs back to the bottom but I want to be sure there isn't a problem here. I've not heard anyone talk about oil at this location before. It is real clean and is not oil from the engine. I suspect all is fine as this would seem to keep the pin lubricated.



The other question is about the spring pressure under the diaphram. The directions I was working from said to remove the top and carefully pull the diaphram up. Heck, the diaphram pushed up from the pump frame all by itself about 3/8". I turned the star wheel down about 1/2 turn but still had to push down on the top against the spring pressure to get the screws back in. Is this much spring pressure normal?



I took the truck out and drove it after these 2 adjustments. Didn't seem to make much difference and there was not much smoke at all. In fact, there seemed to be less smoke than normal. Brought it back home and turned the full load screw in about 1/2 turn. That got me about 1 1/2 PSI increase in boost, still only a haze on full acceleration.



I think about 2 turns down on the star wheel and 1 more full turn on the full load screw are in order. A full turn on the star wheel doesn't move the spring perch down very much. Does it sound like I'm headed for trouble yet?

 

[hdm48]

Paccool, I think you may need to re-read the info on these pumps. When you turn the fuel excentric, you need to make sure the offset is to the rear of the pump. Look at it and you will see that it is not true. Place it back into the pump so the pin (comes from the front of the pump) has the most travel. If you don't understand what I am saying, open the throttle all the way (engine off) and you will see the pin move out into the bore. Make sure you push it back in. Then place the pin back in so the pin in the bore will travel out as far as it can. Don't trust the pick mark, their all off a little.

The star wheel can be screwed all the way down and back it up about 2 turns and try it. If the smoke is too thick, back it up/down some more till you like it.



I think Pastor Bob has a sticky on this and is very easy to follow. Study it closely, there will be a test.



Dave

 

[BushWakr - RIP]

"... . Study it closely, there will be a test..... " :-laf :-laf



OR,... you could wait till dyno day and we could help you with it... . your call.



Seriously though, you should not have that quantity of oil in there. Are you sure it's not fuel you are seeing???? Check that again Stan. . it could just be "over lubed" by well intentioned people OR you can have fuel get into that compartment if the O-Ring on the guide pin is weak or if the guide pin has been traveling out too far and is now failing to to fully return. In that case you may need to have a bit of "top end" pump work. Just a new seal but it needs to be done right and, in a clean environment. Say that's what's needed to do a governor spring too... . fancy that coincidence eh... ...

The symptoms you describe also make me think that you may have a guide pin problem. When you pull the AFC cone, do you see any 'witness marks' on the cone were the pin would normally ride???

Turning the starwheel down (CCW) will result in you fueling rate beginning sooner due to less preload on the diaphram. Go down on the starwheel and you reduce preload which results in less boost needed to trigger cone descent and resulting fueling. Go up (CW) and just the reverse happens. Still, it sounds like there is more investigating need to be absolutely sure buddy... .





Pastor Bob.

 

[paccool]

Dave, I pulled the cone out and looked at it. There is a witness mark about 90 degrees from "minimum fuel" area (Largest diameter of the cone)and the mark is about 3/8" long and centered on the side of the cone. When I rotated the cone clockwise, that brought the smaller diameter around to the pin area, is close to max fuel position on the cone. (the pin can come in farther due to smaller diameter of the cone)



One thing that bothers me is that there is also a "short" witness mark about 60 degrees back from the main mark that is only about 3/16" long. When pumps are rebuilt, is a new cone normally installed or is the old one used? My pump was rebuilt about 2 years ago.



Bob, its oil, no fuel. Looks like 30 weight, is nice and clean. I'll try adjusting a little more tonight, if that doesn't produce what I think it should, I'll take your advice about the dyno.



Thanks guys



Hey Bush, I see you added a comment next to your name about Piers

 

[Greenleaf]

Pump Adjustments

I found my star wheel at the bottom. I'm quite certain this was factory as previous owner had left well enough alone. I turned my cone same as you did. Not much smoke, YET I'm told with the POD Lucas there will be. There is also a witness mark on the control cone, But my fuel pin will not "pop"out when I cycle the throttle with engine off. However it will come out slowly with engine running. Can only get smoke when I hammer it hard or when it shifts into OD on a hard pull. I'll soon see what new injectors do.



Scott

 

[paccool]

Thats great! Does this move you to High Priest yet?



Just keep learning all the neat stuff then keep passing it on and teaching all of us like you have been so good at in the past! Oo.



Stan

 

[dpuckett]

Pacool,



It could just be a case of the pump shop getting a little overzealous with the ass'y lube. Seen it a few times. I agree with Pastor Bob- sounds like you may have a guide pin issue. It should snap out with an audible click when you pull the throttle lever back. If not, get it popped out however you can (pocket knife tip, telescoping magnet), and spray the living beejeevers out of it with some PB Blaster and work it back and forth till it pops out freely. Had the pin get stuck in the front- most position one time, and the truck wouldnt start. But I had to also take the entire AFC housing off to push the pin back like it should.



By lowering the starwheel, you should be seeing fuel come on sooner, at least giving you better acceleration, if not more smoke. AS for the shorter witness mark, is your smoke screw (T25 Torx on top of AFC housing under a brass cap about 1" diam) turned in any? If it started out turned in a bit, the guide pin will start with more fuel off the line, thus leaving a shorter witness mark. I personally prefer to have my smoke screw backed out so it gets minimal fuel at lower boost, and adjust my rate with the AFC spring tension, or starwheel (which looks more like a gear, go figure), thus minimizing smoke and wasted fuel. With the pin being angled like you said it was (basically in the middle), it is normal for the spring to pop the diaphragm up and out when you remove the top of the housing. If it is turned to the max, it will sort of snag on the lip on the bottom of the cone, keping it down a little. Hope I didnt turn any mud into pea soup for you or anyone else here.



Daniel

 

[BushWakr - RIP]

Guys,



About the guide pin thing.....



Ever since I've had the chance to "autopsy" a pump I'd be more careful what I sprayed into the AFC housing. Now I know that little if anything can get past the oring and into the pump top, BUT... is it something that will damage the pump internals, cause wear, or mess up an injector???

I know, I'm being an old hen but use some care. If that pin is stuck it's because the seal around the oring is shot. The very best you can hope for is to soften it a bit and get at least "some" movement out of it.



Just a thought ... .



Bob.



ps: Stan... I stuck to the rules and let TDR admin know that I am now affiliated with PDR. I have the great opportunity to do some time (not how it sounds ) and I'm learning just how much I DON'T know... . but it is a hoot... ...

 

[paccool]

Well, I want to thank everyone for the help and comment. THE PIN IS NOT STUCK! Found that out tonight after making a few more adjustments. Took the cone out and set it for max fueling. Took the starwheel down another 1. 5 turns. Turned the full load screw in another 1/2 turn. Was going to turn the smoke screw in some but found the thing all the way in already. Any more and the lock nut will fall off.



Took the truck out and saw 28 PSI on the freeway get on ramp, truck was empty. Looks like I'll need to turn the smoke screw back out a little now. When cold, I could fill a car with smoke in a heart beat! After it warms up, not much more than a heavy haze most of the way from stop to freeway speed.



Idle is high, need to get to the screw and set it down. Also want to check the breakover spring to see if the throttle link is set right.



End of story is that the truck is running a lot better than it was! Oo.



PS - just noticed what my post count is. This is a good one for the 1000 milestone!

 

[db811]

Dredging this post up from the archives... . I recently got my hands on a 91. 5 w250 which has been smoking a bit excessively since I bought it. I finally pulled apart the VE pump and made some adjustments (in the opposite direction from the usuall) and in the process noticed that I too have oil down in the bore when I pull the eccentric out. It's definetly oil, not fuel and it doesn't appear to be too clean -- had to wipe the eccentric off and clean some deposites around the 'witness mark' with a fingernail...



Basically just wondering if I should worry about cleaning it out or leave well enough alone.



Adjustments didn't do much for the smoke but in the process I noticed a healthy crack in one of the turbo boots, (post intercooler) so I think I'll get that fixed before I do anything else with the pump.



Thanks, dave