Hey guys I pulled my intake off today to take off my PMD so I could re-locate it and I figured why not go ahead and play a little bit with the optic sensor. so what am I looking for on the pump what does the sensor look like and how do I "bump" it. How much power will I gain? Is it noticable? Thanks for the help.

Remove the 6 small torx's screws from the top of the IP. Loosen the 40 torx's screw and slide the block over relative to the screw toward's the passenger side about 1mm. If you go to far your idle will be high and eratic, up until that point it seems to make more power. I adjusted mine about 8 times before I found the spot I liked.

so do you actually take the top of the pump off?

yes, its just 6 torx bits, trust me, its not as big of a deal as it sounds, once you've tried it, you'll be happy and you'll say 'man, that was easy!'.
Its been posted so many times, with pics....when you get the cover off, loosen the T40 bit, and move the optic sensor underneath ~1mm to the pass side.

On your '94, which is probably a 5068 pump, you probably want to move it less than a mm and you will notice a big improvement.

The lid will be connected by a wire harness do not attemt to disconnect. Just lay the lid over to the side and adjust the optic.

What does the optic sensor look like? Does anyone know the link to one of the posts with pics? thanks

Do a search on "optic bump", i've posted a few pics on it.

Here's a link to CR's post. I needed to look it up and take another look at the pics to try and figure out what I'm doing wrong anyways. Scroll about half way down the page. There's a GREAT picture showing exactly where to move things when setting the bump. http://dieselplace.com/forum/showthread.php?t=14231&page=2&pp=10&highlight=optic+bump

http://www.dieselplace.com/forum/images/smilies/help.gif Need some serious help here, well I just relocated the PMD hopefully I got the wiring right! Heres my problem I did the optic bump and i know that if you adjust it too far that you will have a high sporatic idle and all but I adjusted it several times and still couldnt make it run right. Kind of sounds like it has a cam in it in the past ive been around some diesels mostly larger ones with different style pumps that had air in the system thats what this sounds like to me. Is it possible that mine has air in it? do you have to bleed the system when you so the "optic bump" if so how do you bleed the system . Kinda need the truck this weekend hoping I can get it running by then If nothing else can someone tell me how to put it back to stock? When i did it the first time I didnt mark it so I dont really know where it washttp://www.dieselplace.com/forum/images/smilies/frown.gif is the stock setting all the way to the stop on the drivers side? Thanks for the help

All the way to the stop in either direction is wrong for sure.
From what you describe, you went to far, and I stress, in your unique application, this is a more sensitive adjustment than those with 5521 series pumps.
For a base line, set it so the lock plate is centered on the body of the sensor underneat it and try it. If you get white smoke, you need to go to the pass side, if it clangs, runs rough, idles high then you need to go to the drivers side.

1mm is the maximum you should move it over so the range you're targeting in is less then that. I wouldn't be concerned with air in fuel, the first couple of times I moved my optic I drained the bowl with a rag. Then I just started adjusting it with fuel in the bowl to save time. It's difficult to adjust within the 1mm so the best bet is to get it running smooth near the center then move in small increments toward the pass. side till it get ruff then go back.

So air is probably not my problem then?

Air inside the part of the pump you can see wouldnt' cause a problem, so you can rule that out. Are you going to try it some more?
Also, keep in mind that there is a small amount of play in the lock plate.
Best way to keep track is to loosen the bolt until its free, and with a screw driver push it to the driver's side and make a scribe mark on the pass side of the plate. Then, everytime you go back to adjust it, you reference your scribe mark the same way, taking the lash out by pushing to the driver's side. If you have a scribe mark on the cam ring, you can put the edge of the sensor right on it and you should be right at the original position. Few 5068s have this though...

Yeah Im going to have to try it some more its not even runing good enough to drive right now from the sounds of things seems like I adjusted it too far to begin with then got scared and moved it too far to the drivers side and really got it out out of whack. So the very center of the pump is pretty close to factory right? Ive got some time tomarrow to work on it and if nothing else I guess ill have to sacrifice this weekend to the truck.

Hey, get a chance to work on it some more???

Both of the 5068's I've looked inside had the factory line but it sits under the sensor and can't be seen unless you remove it.

I can only remember seeing one 30501 cam ring with a line scribed on it, but it was on the opposite side of where its supposed to be.

Finally got a chance to work on it some more today figured out all I was doing was rotating the cam ring back and forth this whole time which might explain why it wasnt doing anything http://www.dieselplace.com/forum/images/smilies/confused.gif but I finally got it to work I think I might be able to advance it a little furthur but im going to wait untill I get a way of turning up the boost, isn't there some way you can wire in a knob controlling resistance from the boost sensor to fool the comptuter so it could be adjusted on the fly?

yes, you just wire in a veriable pot. or fixed equivilent on the MAP sensor and the ECM will allow ~15+ psi.

So if you figured out that you never actually moved it before, why were you saying that you were having trouble with it and the engine was running louder?

How does it run now that you've successfully bumped it? When you get it right, and you cheat your boost up you should REALLY notice an improvement with that pump.

Well I guess the first time I must have moved it just enough to make it run rough,
Now after the bump it runs pretty good i think I can still bump it some more but I think I can still move it a little more but im going to wait until I can get more boost which I am hoping to do tomarrow. So which wire do I hook up the pot to?

http://dieselplace.com/forum/attachment.php?attachmentid=373 This is a schematic I did for a veriable pot. on the MAP.

You can soder in fixed resistors. Last time I did it took 800 ohms off the (B) wire and 2400 ohms jumping back to (A) ground.

You can do it that way, but the 'easy' way, is just to wire the pot off the middle wire going to the map sensor.
10k Ohm Linear Taper Potentiometer (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=271-1715) $3, I used speaker wire for mine, just makes keeping the two wires you will need to plumb to your dash together easy.
You'll want a Control Knob (http://www.radioshack.com/search.asp?find=knob&site=search&SRC=1) too.
10k on the 'B' wire is good for 10psi sustained, which is perfect match for optic bump.

Hey Bass, how about a cheap power chip for your '94? Or anybody else who's interested...
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=7971571168&sspagename=STRK%3AMEBI%3AIT

Damn! They always gotta be for a stick!

Oh thats right, it only works with 5 speed....

Yeah sounds like a good deal but I got the automatic thinks anyway though, I just bought the 10K pot Quick question so the only difference between the TDG design and QMs is QMs design has the a wire connected to the first wire on the pot whats the difference? Is one terminal on the TDG design left alone? Just a little confusion on my part. Thinks

If you go with the way I described, just solder one wire to the center terminal and one on the side, either one, only difference is which way you want to turn the knob for more boost.

Actually, how tex told you to do it is how I ran it for a year before I changed it to the way I showed you. The difference is you'll get full WGDC on the three wire pot.
That means WOT you'll see 16, 17, 18+ psi if you have the turbo hot enough maybe 20 or 21 psi, or as I like to think of it, piston cracking hot, LOL.

Thats true, both are his idea.

Not really my ideas. JK and A-1 both have boost foolers, I just hacked it out.

Hey guys did the optic pump and the boost fooler can definatly tell a difference in the truckhttp://www.dieselplace.com/forum/images/smilies/rockon.gif Hoping somtime in the next few weeks to free up the exhaust some im on a pretty tight budget and all {poor college student} http://www.dieselplace.com/forum/images/smilies/hihi.gif so all these cheap tips and tricks are awsome! Thinks for all the help?