Governor mod

[zaprzal]

[fspGTD]

The governor mod is "advanced," because it requires opening up the fuel pump.  It is very sensitive and complicated with lots of small parts, kind of like a carburator.

Before attempting this mod, you should be armed with technical information on the VE pump.  I have been collecting this over a few years time, scanning it in and putting it linked to this page.  Here you will find descriptions on how the pump works, related terminology (what its parts are called) and useful detailed parts blow-up diagrams:
http://home.comcast.net/~vwgtd/vepump.htm
Read and study these links well before attempting going inside your own VE pump.

Although there are not yet any threads detailing the steps to do the governor mod yourself, there is a thread where I detailed my experiments and test results which developed this mod (in this thread: http://www.hostboard.com/cgi-bin/ultimatebb.cgi/ubb/get_topic/f/4037/t/242 ) and also there are more recent threads of others asking for additional information, trying it or other variations, and relating their experiences with it:
http://www.vwdiesel.net/phpBB/viewtopic.php?t=157
http://www.vwdiesel.net/phpBB/viewtopic.php?t=1186
http://www.vwdiesel.net/phpBB/viewtopic.php?t=1230
http://www.vwdiesel.net/phpBB/viewtopic.php?t=1758

I will summarize the steps to do this mod yourself below.

The modification can be done with the pump installed on the motor (and steps below will assume this is how you're doing it), but it will be easier and less risky if it is done with the pump removed from the motor.  There will be less risk of some sensitive part being dropped and lost, or diesel fuel draining all over your coolant hoses when the pump is opened up etc.

Disclaimer - perform these steps at your own risk - putting the pump back together wrong can result in a very difficult to fix problem and even severe engine damage!  That said, on to the steps...

Before removing anything than opens up to diesel fuel, clean off all the external dirt first.  Spray solvent, compressed air, paper towels, etc.  Don't let any dirt get inside the injection pump or into the areas where there is fuel.  If the engine is particularly nasty, pressure wash the area first.  Work in a clean environment - inside preferably but if outside, should be when there is no dust or wind.

1.  Disconnect LDA boost tube (small rubber hose.)  Pop off accelerator pedal connection to ballstud on input throttle shaft on pump.  Remove two 10mm bolts holding throttle pedal bracket to top of pump and remove throttle pedal bracket from pump top.  Mark position of throttle arm on shaft (in particular the orientation of the line on the top of the stud in relation to the throttle arm.)  Remove the 10mm nut on the top throttle shaft and remove the throttle arm and the return springs.  Keep all the pieces in order on how they are put together, so they can be reassembled later.

2.  Prepare governor cover for removal as follows:  Crack open one of the small fuel return hoses and allow air to bleed into the fuel return line.  Remove the fuel return banjo bolt and pull away the fuel return banjo fitting, and wrap a rag around the banjo fitting to keep dirt from getting in and set it aside.  Set up paper towels to catch any diesel that drains out of the pump - keep it off the radiator hoses (diesel on radiator hoses must be thoroughly cleaned off as it will attack the rubber over time.)  Set aside in a clean spot the copper crush washers and banjo bolt for the fuel return fitting for later reinstallation.  Everything should now be disconnected from the governor top.
Photo of a turbo-diesel pump ready for governor cover removal, courtesy of Mark, AKA dieselpower:


3.  Remove governor cover.  It is held on by 4 allen-head bolts.  I recommend not disturbing the fuel screw.  Some diesel will probably spill as the governor cover is cracked open - I recommend catching the spilled diesel with rags or paper towels before they touch the coolant hoses.  After removing the allen head bolts completely, the governor cover will only be held on by the governor mechanism.  Sometimes it can be easily disconnected from the tensioning lever, but only if the orientation of the governor is right (there is a slot it fits though, but only if it is rotated to the proper angle.)  What I would recommend is pushing the throttle lever shaft down through the governor cover as you lift the governor cover off of the rest of the pump, so the whole governor mechanism including the throttle input shaft is left behind attached and on top of the pump.  Be careful not to bend or otherwise damage the governor when doing this!  Leave diesel filled up to the brim in the main pump cavity to make the pump easier to start back up.  After the governor cover is removed, set it aside in a clean spot.
Photo (courtesy Mark / dieselpower) of what the pump looks like with governor cover removed:


4.  Remove the governor assembly from the tensioning lever.  You will find the governor assembly when rotated correctly will come off the tensioning lever through a notch.  You should now have the governor assembly removed and can work on it to perform the modification.
Photo (courtesy Mark / dieselpower) of throttle shaft / governor assembly removed from pump:


5.  Modify the governor to eliminate the intermediate spring as follows.  Measure the travel of the intermediate spring by pulling on the ends of the governor capsule.  (The intermediate spring is the first one of the two inside the capsule that compresses.)  You can see the intermediate spring seats are wide things that only allow a small amount of spring travel:


Find a shim that will take up this movement when inserted between the intermediate spring seats at the area where they are closest to each other.  3/16" aluminum pop rivet backing washers are of suitable ID and OD, but you'll need to arrive at the right overall shim thickness (possibly re-using the original shims between the intermediate spring seats if present and if needed.)  The idea behind the shims is to fix the intermediate spring solidly in the extended position, so it can be removed.  Insert the shims by disassembling the governor capsule as follows:  First remove the circlip on the end of the idling spring.  Remove idling spring and it's spring seats, and set them aside in proper order so they can be later reassembled.  Press the outer intermediate spring seat into the governor capsule and lift it up and away of the pivoting structure that is riveted to the throttle arm.  Then slip off the outer intermediate spring seat and the intermediate spring and insert shims needed to disable the intermediate spring.  Slip the outer intermediate spring seat back over the shaft, and compress it and reinstall it into the governor capsule bracket that is riveted to the throttle shaft.  Test the springs to make sure they are not loose in the bracket.  Reassemble the idling spring and their seats and circlip.

6.  Insert the governor/throttle shaft mechanism back onto the tensioning lever, engaging the slotted area of the shaft through the slotted opening of the tensioning lever.  Rotate it so it is engaged securely when installed.

7.  With the throttle shaft in the correct orientation, lubricate the throttle shaft o-ring with clean diesel fuel and press the governor cover over the throttle shaft.  Push the governor cover down onto the pump and slide the cover towards the high pressure fuel output end to engage the fueling adjustment screw and align the governor cover with the bolt holes.  Reinstall the four allen head bolts and snug them down (to I'd say about 7.5 ft-lbs.)

8.  Put everything else back in reverse order from how it was removed.  Duplicate the original orientation of the throttle shaft on the arm that was recorded in step one by getting the throttle arm onto the correct spline position.  Fire the engine up and make sure that there are no newfound diesel leaks - if there are any fix 'em before they leak diesel all over the place.  That's it you're done!  Enjoy your newfound horsepower and powerband. :twisted:

[deepmud]

thanks for summarizing - I have ready most the posts on it, but I copied this post to my hard drive.

[zaprzal]

Big thanks   That's what I've been looking for  

[fspGTD]

You're welcome guys!  I added a few pics to help explain the procedure a little better and I also linked to this thread from the FAQ section thread title "more power".

[fatmobile]

I'm a little clumsy so I always stuff rags around the pump so if I drop anything it doesn't get lost behind the pump or make me go looking for it.
  To get the fuel out of the pump before I opened it; I disconnected the return line (after removing one of the small lines and letting some of the fuel drain back to the tank, like Jake suggests). I disconnected the fuel input line and ran a fuel line from the input to a container (rag handy). I put a fuel line on the return line and blew on it to force fuel out the input and into the container at the ready (actually used a tire pump to force fuel from the pump this time).
 I got an injection pump seal set so I could replace the old seal and o-ring while I was in there. I'm not sure the old seals are made to deal with biodiesel like new seals are.
 I should have taken a picture of the spring replaced with a washer while I was in there.
 Since I removed all the fuel from the pump, I had to reprime it. I disconnected the power wire so no air was pumped into the injectors and put a regular banjo bolt in the return. Cranked the engine till fuel was flowing out the clear return line (doesn't take long with the restricted banjo "OUT" bolt out of the picture), then put the "OUT" bolt back in and plugged power back in.
 This mod got rid of the surging I felt during normal driving, around where the turbo was starting to kick in.

[veeman]

Jake (and others)...

Thanks for the write up on this mod.  This is something I'd like to do on my TD.  Last night I took apart a junk 1.6NA pump (stripped pulley shaft) and examined the governor.  

A few observations / questions:

1.  When I originally took off the governor cover, I left the throttle shaft in the cover.  The governor obviously didn't want to come out of its slot below.  I later tapped the shaft out of the cover like you suggested.

The problem I had was putting the cover back on the pump.  How do you effectively get the throttle shaft to press all the way back into the cover once the governor is hooked to the arm again?  Seems like once it's hooked up, I can't get any leverage on it to press it back in.  If it's not seated, it seems like it will press on other pump internals.  I assume that's not good.

2.  Next, when putting the cover back on, it seems like the fuel screw / arm interfere.  Obviously the arm at the high pressure end in the corner is under signifigant tension, but it doesn't seem to want to let the cover sit down correctly.  Did I move something and misalign it?  Is there a secret to getting the cover to line back up with its holes?

3.  You mention the "idle spring".  Is that the very light spring at the end of the governor assembly (the end farthest away from the throttle shaft)?

4.  Finally... As described above, are you replacing the intermediate spring completely with something rigid?  Can you explain to me how does this effect the governor's function?  

I'm assuming that it slows the "taper" at which the fuel is cut as the rpm's rise.  A sleeve / object instead of the spring would make the parts in the governor capsule unable to move until enough pressure is applied to engage the main spring.  Is that right?  How does that transfer into what I'd feel when driving the car?

Thanks for the help.  Messing around with the pump seems daunting and overall, I'm glad I was experimenting with one that wasn't on the car at the moment...

[fspGTD]

Answers for veeman:

1. It's the o-ring at the top of the throttle shaft that makes the resistance when pressing it into the governor cover bore.  Clean the bore with solvent like brake parts cleaner.  Lubricate it as well as the o-ring at the top of the shaft with diesel (or maybe even try something a little slipplier, like motor oil.)  Just don't press it in dry!  To get the throttle shaft started into the bore, I usually put my finger underneath the throttle shaft to get it started and press it in that way as far as I can keep my finger there.  When the cover is down so far that I need to remove my finger from underneath, I haven't had a problem just pressing it down lightly the rest of the way.  The cylindrical flyweight holder should be stout enough to withstand the needed pressure, just don't force anything!  After the cover is pushed down all the way and the four bolts are installed, grab the threaded top of the throttle shaft and pull it all the way up, or install the throttle arm and tighten the nut to pull the shaft all the way up.  Just make sure to get the throttle arm oriented correctly, which can be a bit tricky while holding against those springs.

2.  The quickest way is as I've described above: set the governor cover down a little bit towards the pulley end, so the end of one of the governor levers is at the side of the end of the fuel adjust screw, and then it gets tensioned when the governor cover is slide away from the pulley end until the hollow dowel pin engages and bolts can be installed.

If you are having problems with this method, there is another way, which involved completely or nearly removing the fuel adjusting screw.  If you do this, be sure to measure it's position before you remove it and/or count turns, so it can be put back in exactly in the same position as it was originally - to the nearest fraction of a turn.  If you forget or mess up it's position, you have a real risk of making your pump really hard to start or setup so it will melt your engine down shortly after it starts.

3.  Yes.

4.  You've got it...  The mod maintains full fueling to higher RPMs, whereas when it was stock the fueling would gradually drop over an RPM range before the main revv limiter kicked in.

With the governor mod, the car will feel the same as it did before in all driving conditions, until the pedal is floored and the revvs climb up, at which point the car will go like a scalded cat all the way until it hits the main revv limiter, instead like a wheezing its way up there like it originally did.

hope this helps...

[leprechan]

I have attempted this mod a few times and I can never get my engine to run properly afterwards.  The engine doesn't want to return to idle like it did before the mod.  The revvs go up and don't come down or come down very slowly in some instances.  My pump is an elevation-compensation variety.  My car being a 91 has just about all the adjustments that the AAZ engine pumps have.  I think it is just an issue of inproperly adjusted residual fuel pressure.  After looking at the pictures in Smog's DIY thread I think maybe I need to adjust screw #8 and then screw #6.  Hope that makes sense.  I would love some help figureing this out.  Thanks

Nick

[fspGTD]

When modding the governor with good predictable results, you should only change one variable at a time (which is for the purpose of the governor mod, the intermediate spring.)  So you should either leave all the other pump settings where they used to be, or strive to return them to stock settings if they need to become upset during the procedure.

I haven't played with the idle-speed changing throttle linkage pumps much before (and you may notice that my instructions above don't cover them), but it sounds like you are on the right track with suspecting an altered residual fuel adjustment.  Other possible explanation is the fuel quantity adjustment screw setting was altered by getting screwed in, but that would be accompanied by extra fueling and probably smoking.  If everything was left set stock except for disabled intermediate spring, the pump is going to idle and behave at low loads exactly like it did before.

[leprechan]

I have never removed the fuel screw and have moved half turn at most from stock setting.  When I took the pump apart the only thing I really disturbed was the idle stop screw(residual screw) and the throttle lever.  I have never messed with the idle screw so I'm hoping that will help in bringing it back to idle normally.  When I put the throttle lever back on I can't line the spline to the marked line or it will not idle even with the stock governor setup.  Right now it is two splines over.  Would a normal na pump top without all this extra junk make it easier to mod?  I will do some more experimenting maybe Friday and keep you updated.

[veeman]

Thanks Jake!

>> 1. It's the o-ring at the top of the throttle shaft that makes the resistance when pressing it into the governor cover bore. Clean the bore with solvent like brake parts cleaner. Lubricate it as well as the o-ring at the top of the shaft with diesel (or maybe even try something a little slipplier, like motor oil.)

I see what you mean.  I'll have to try that again.  When doing this mod, do I need to replace that shaft seal or the cover gasket?  Not sure if that's a leak prone area or not.

Also...I'll be running biodiesel here soon up to around B40-B50.  Maybe replacing those seals would be good to do in preparation.  Anyone have a source for the O-ring and the gasket?

>>The cylindrical flyweight holder should be stout enough to withstand the needed pressure, just don't force anything!

That's what I was afraid of pressing on... that flyweight wheel.

>>If you are having problems with this method, there is another way, which involved completely or nearly removing the fuel adjusting screw.

I think I'll try the other method first.  No need to melt the engine just yet.

4. You've got it... The mod maintains full fueling to higher RPMs, whereas when it was stock the fueling would gradually drop over an RPM range before the main revv limiter kicked in.

I've got to come up with some sort of spacer, then I'll test it on the junk pump before I do it on the TD.  I don't want to remove it from the engine if I don't have to, but we'll see.   Besides rivets, what have others used for the intermediate spring spacer?

[fspGTD]

Besides rivets, what have others used for the intermediate spring spacer?

Did I say 3/16" pop rivets?  :oops:  I meant 3/16" pop rivet backing washers!  (Note: I updated the instructions to better communicate this.)  Although you could possibly take the original intermediate washers off one or two junk pumps and install them into one working pump, 3/16" Pop rivet backing washers are readily available at nearly any hardware store.  I'd imagine pretty much any other 3/16" ID washers could be made to work too. :wink:

PS - yes, it's always a good idea to replace 20+ year old rubber parts with new!  The old rubber o-rings and gaskets loose their resiliency and take on a set over the years and heat exposure.  New fresh ones will seal more reliably.

Edit: Given people seem to ask frequently about the governor mod, I moved this all-encompassing governor mod thread to the frequently asked question section.

There is also a new thread posted by VWMike, clarifying the governor mod.

[punkvideo81]

I have a question -

Just got my Giles pump installed yesterday. It is on a 1.6td rabbit with a full 2.25 in downpipe/exhaust, with a k&n air filter/big tube intake pipe and an intercooler from a porsche 944. My mechanic did not turn up the boost from stock yet because we didn't have enough time to install the EGT and he said I will definitely want a boost gauge as well. My question is - should the car be pushing a lot of smoke out the exhaust at roughly 3/4 throttle? Is there a way to adjust it so I am not doing that as much or is that what comes with the territory now? I will be at Waterfest tomorrow, where I hope to pick up a Boost gauge.

[hillfolk'r]

in a pinch,grab an old  mech oil pressure guage,,or any old mechanical pressure guage
in a pinch,ive used the guage from my shop compressor
to give you an idea,im using a summit digital oil pressure guage for my lift pump pressure