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.htmRead 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=157http://www.vwdiesel.net/phpBB/viewtopic.php?t=1186http://www.vwdiesel.net/phpBB/viewtopic.php?t=1230http://www.vwdiesel.net/phpBB/viewtopic.php?t=1758I 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: