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Engine Specific Info and Questions => IDI Engine => Topic started by: leprechan on October 27, 2004, 10:48:41 pm
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Greetings from the land of slow NA diesels. I've heard about all these nifty mods for the TD pump, mainly the governor mods. Has anyone had any experience doing this to a na pump? I know about Giles modified pumps, but I had mine rebuilt about 10k ago and I need my car on a day to day basis. I’ve been reading over tons of posts over the months and nobody really talks about na pump mods besides turning in the fuel screw and setting the timing to 1.0(which I’ve already done :) ). If anyone has any insight on how I would perform this pump surgery I would be very greatful. Oh, BTW my pump has the atmospheric compensation unit on top if that changes anything. Hope to here from you soon.
Nick
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Short of sending your pump and injectors off to Giles to have him work his magic on it, there are a couple of things you can do yourself. Here they are, in no particular order:
First, do the simple advance mod, i.e., adjust the top of the pump towards the block. The procedure is discussed in a couple of recent threads, but I can't find them right now. You'll have to do a search, or maybe someone can point us in the right direction.
You may also wish to do the governor mod, originally discussed in this thread (http://www.hostboard.com/cgi-bin/ultimatebb.cgi/ubb/get_topic/f/4037/t/242), and then updated here in the new forum in this thread (http://www.vwdiesel.net/phpBB/viewtopic.php?t=157&highlight=).
Finally, modifying the injectors' pintles to get a faster injection seems to help. The procedure is discussed here (http://www.vwdiesel.net/phpBB/viewtopic.php?t=304&highlight=pintle+injectors), but only indirectly. You'll have to search more, but I have to run to work now.
Hope that helps, but as always, proceed at your own risk... :D :wink:
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I'm attempting the governor mod and got the 4 allen screws out, but I can't get the lid off. Something is still holding it down and I don't want to brake anything by prying. If anyone could help I would be greatful. Thanks in advance.
Nick
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Also once I took the 4 allen screws out that hold the governor lid down, I coudn't put it back on flush to the pump body. I hope one you diesel gurus comes online sometime tonight, because I would hope to either get the lid off for the mod tonight or put it back on so I don't get the inside ot the pump dried out and I don't get any crap in there. Thanks in advance.
Nick
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You may need to remove the full load screw to get the lid back on. I generally measure the distance from the end of the screw to the face of the lock nut. Then loosen the nut and back the screw out. Once you have the cover back on you can thread the screw back in to the pre-determined measurement.
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Thanks HIGH PSI I'll try that. BTW do you know what I have to do to get it off. It looks like I have to disconnect that lever from the governer spring assembly. Hope to hear from you soon.
Nick
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There are two ways to do it. One is to remove the throttle lever (after marking it in relation to the shaft, and removing the spring tension) and push the throttle shaft down through the cover. The other is a bit trickier if you are doing this on the car, but the governor spring assembly has a flat spot on the round shaft that runs through the springs. This shaft can be turned in the proper relation to the governor fulcrum arm that comes up out of the pump so that the flat spot comes up out of the governor fulcrum arm slot. Hope this helps.
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Hey thanks for all the help HIGH PSI. I pushed the throttle shaft through the cover and it came right off. I put two nuts in the spring pack of the main governor spring to raise the governor. I didn't have to take the full load screw out either. I used an old "fishing trick". I got some 20 lb. test fishing line and looped it around that arm that the full load screw sits against and pulled it out of the way. The lid went down smoothly that time. My only problem is I had already taken the the throttle lever and springs off before you replied and I didn't mark them. :cry: stupid stupid me, HEAD HIT WALL! If someone could offer me some guidance to putting those springs on and lining the throttle lever up correctly I would be happy to put my diesel back on the road with some much needed extra power. Some pics would be great too if anyone has any that would help. Thanks in advance.
Nick
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Surely there must be someone out there who has taken off the throttle lever and springs and put them back together again. I would really like to get this back together tonight. Any help is extremely appreciated. I know its not anyone else's responsibility to be my encylopedia of diesel so sorry if it sounds like i'm whining. I hope to hear from someone tonight.
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hey,
it's pretty late right now and i have school tommorow so i dont have time to check it out but if i have time afterschool tommorw i'll take some pics and show you how to put it back together.
Mark
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Hey thanks Mark, I look forward to hearing from you or anyone else with some input later today. Can't wait to get out of the slow lane and into the slightly quicker lane lol.
Nick
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hahaha, ok
so i took it apart last night but it was late and the pump i took apart was a lil different then the one i usually work on....anyway i have it all set up so i knew witch parts went where but,.....i dropped them **head hits wall**
anyway now i cant figure out how it goes back together. its not the same as the pump on my car so i have nothin to look at.
so if anyone can help, it would be very much appreciated
Mark
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ah crap lol. Now we both need help. Seriously there must be someone else out there with the time and energy to help out. Help from anyone whose done this would be appreciated.
Nick
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I have one more question though lol. I can turn the shaft clockwise and it will hit a wall shortly, and I can turn it counterclockwise or towards WOT and it will start to get tight around the governor springs. So my question is where does the shaft need to be when the throttle lever is put on? Any help is appreciated.
Nick
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Well I finally figured that spring thing out and got the throttle lever on, but I can't get it to start. The pump is not priming itself no matter how many times I crank it. It does quite a bit of stuttering like its trying to start, but never quite makes it. I've tryed loosening the injector unions to let the air out while cranking and I got fuel coming out so I tightened it back up and tryed to start it again. I'm kind of thinking there might be an airlock in the lid somewhere but I'm not sure. I tried putting atf in from the return outlet, but that didn't seem to help any. Any ideas out there? Or anyone near the southwest corner of Washington hehe? Any help appreciated.
Nick
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Try flooring it to start it. If your throttle lever is not aligned right you could be below idle position and not have any/enough tension on the governor springs. You need to have the throttle shaft twisted about as far counterclockwise as you can with your fingers when you put the throttle lever on in the idle position. I often put the lever on before hooking the springs back up so it is easier to get everything positioned right. You could actually try starting it without hooking the springs back up everytime if you had someone there who could act as a return spring for you and move the throttle lever from under the hood. It may take a few tries repositioning the lever until you get it to idle at the right speed again.
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hey,
on the throttle shaft there is a line like a flat screwdriver would go in, and on the throttle lever around the hole where it mounts to the shaft are three lines that cross the hole. you have to line up the line on the shaft with one of the outside lines, not sure witch one at the moment then it should run right...it might just be coincidence but every pump i've seen has it lined up on the same line..
hope this helps
Mark
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My pump has about a dozen or so lines for adjustment on the throttle lever. I noticed a dimple in one of the lines, it looks like it was put there by a punch or something. Is it possiblel it was put there during the rebuild? When I put the throttle lever on I twisted the shaft until I felt the governer springs and that was about where the line where the dimple was. Another possability I was thinking about is the 4 allen screws that hold the lid down. What do you torque those things down to? I remember them being really tight so I tightened them the best I could with the pump in the car. I thought I did a pretty good job at getting them tight, but maybe not. Comments welcome.
Nick
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It is a good possibility that the rebuild shop put the dimple there. When I am rebuilding a VE pump, I will usually scribe a line on the top of the throttle lever, but I know some shops are center punch happy.
As long as the top cover gasket doesn't leak, and the screws aren't so loose that they will vibrate out, you should be alright.
What all did you do while you were inside the pump. Usually the best way to troubleshoot something is to start at the beginning of when the problem started, and see what may have been done that could be causing the problem.
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Thats a good idea HIGH PSI. I'll make a nice little list out of it.
• Removed the throttle cable.
• Removed the throttle cable mount.
• Removed the throttle lever and springs.
• Removed the idle stop stud.
• Removed the return outlet banjo bolt.
• Removed the 4 allen bolts.
• Fiddled with the lid for a while.(couldn’t figure out how to remove.)
• Pushed the throttle shaft through to remove the lid.
• Unhooked the governor spring assembly from the pump and replaced the lid.
• Found two small nuts that would fit the shaft and clear the retaining clip.
• Thoroughly cleaned the nuts with solvent.
• Added the nuts to the governor assembly to increase the preload to the main spring.
• Cleaned the whole assembly with solvent again.
• Replaced the governor assembly in the pump.
• Pushed the throttle shaft back through the hole in the lid.
• Tightened the allen bolts back down.
• Replaced the idle stop stud.
• Replaced the return banjo bolt.
• Tried to add atf through the return fitting.
• Fiddled with the springs and throttle lever for a few hours.
• Figured the whole spring setup the next day.
• Tried to start.(no good lots of sputtering)
• Loosened the injector unions and cranked.
• Fuel comes out and injector unions are retightened.
• Try to start again. (same thing lots of sputtering)
• Lots more trying.
• Battery dead. Put the charger on and called it a night.
• Present day lol
Hope this helps you help me hehe.
Nick
--edit--
If the top cover gasket is leaking will I see fuel leak around the side of the pump or will it suck air?
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i don't have a gasket on the top cover of my pump. anyway the inside of the pump is pressurized so i would assume u would get diesel on the outside of the pump if there was a leak there.
oh, and make sure the linkage is all hooked up on the inside of the pump...when i removed my govenor the linkage came aprt when i put the pump back together, not sure how tho, and no matter what i did with the throttle lever it wouldn't start...i even got my dad to tow me around the block to try and start it it trie but just wouldn't go...i thought it had something to do with the goven so i tried to take the cover back off and it wasnt connected....
hope this helps
Mark
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Is the linkage where you have to rotate the governor assembly to that flat spot to reassemble. I really don't want to take it apart again, but if I can't get it to start I may have to. I'm gonna go play with it a little bit more then maybe check back here before I start surgery. Thanks for the info.
Nick
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i don't have a gasket on the top cover of my pump. anyway the inside of the pump is pressurized so i would assume u would get diesel on the outside of the pump if there was a leak there.
Mark
There is not a paper gasket, but there is a molded rubber square cut o-ring in a groove in the top cover.
leprechan:
when you were re-assembling the governor linkage with the two nuts did you notice how the spring seat on the open end of the frame had two little notches to seat it into the frame? If they weren't seated correctly it could have come apart like dieselpower said. Also where did you put the nuts? In place of the intermediate spring?
By the way, don't try to start the engine with the charger on boost/start. If you do you can kiss your glow plugs bye-bye. I always use boost/start in between trying to start, and then turn it back to low to glow plug and crank.
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Don't worry I took the charger off before I tryed to start it. I got to messing with it for a while and finally got this one allen in the back a little tighter. Man that thing is a *** while its in the car. I cranked on it a few times and almost got it started but no luck. So then I got my electric pump out to prime it. I ran it out of a quart of atf. As soon as its started it starts to rev uncontrolably. I'm kind of thinking I have the throttle shaft too far towards WOT. I'm gonna take a lunch break and check back here before I go out to work on her again.
Nick
--edit--
I put the two nuts with the itermediate spring. It slightly compressed the intermediate and compressed the main spring a bit more. It all seated correctly when I put it together.
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did you try turning down the idle and full load screws? try turning them down so that it idles without reving. or you can try turning back the throttle lever like you said...if you are careful you can trun it without having to take the whole thing off and put the springs back on again.
hope that help somewhat
Mark
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im just curious...how thick are the 2 nuts you put on there to preload it?
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I got it to idle correctly, but it defuels really slow now. If I rev it high enough it doesn't want to come down. I had to turn the idle stop in quite a ways for it to idle. I tryed turning the shaft one notch more, but it starts to overrev again. I'm kind of at loss of what to do now. Any help is appreciated.
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I wish someone had some good pictures of this one. I know what the inside of the injector pump looks like but I'm still trying to figure out what you guys are talking about.
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thats is exactly what happened to my pump when i removed the govenor. supposedly it's because of a high internal pump pressure that it has a sticky speed. anyway i tried expirementing with different return orfice size and goining bigger there helped stop that problem but when i made it bigger it also started fueling less due to the vane pump pusshing all the fuel back into the tank before the car could use it. also at higher rpm..around 4300 it would miss and stop due to the pump not getting enough fuel from the tank. if you back out the full load srew some more this will go away....but then you loose some of the fueling.
the only way around thid i can see is to get a bigger plunger or put in a 1.9 camplate with more lift
hope this helps
Mark
P.S. i left it how it was and just learned where that starts to kick in and either shift below that or shift really fast above that point..i also have a little bit bigger orfice on the return to raise that point but i also loose some fueling.
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vwmike,
when i decide to get dressed ill take some pics of the inside of a pump for you to see.
Mark
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ok,
here are some pics of govenor.
you have to either shim or replace the 2 springs on the left to make them reallystiff.
http://www.cardomain.com/memberpage/418501/3
sorry bout the blurry pics...my digi cam isn't really good at closeups.
hope this helps
Mark
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Wow that kind of sucks to hear about this now. Would you say it has better performance the way you have it now? There must be someway to make it function properly with the higher governor. The nuts I used to preload the springs were about 3cm in length and made the springs pretty hard to compress. What if I removed one of them? Would that help to get rid of that sticky spot, but still have a slightly higher governor? It seems like quite a few guys on the board are running altered governors on their pumps. It would be nice to hear from them on how they dealt with this problem. Maybe giles or Dr. Diesel could chime in somewhere. I would really appreciate hearing a few more comments from people running modded pumps before going to the trouble of taking it all apart again. I need it to be reliabe as its my daily driver, so I have to make it work one way or the other tomorrow. I hope to hear from someone soon. Oh BTW Thanks for all the help dieselpower and HIGH PSI.
Nick
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my govenor is only shimmed like 1/8th of an inch and it still does it...it seems like only us two have had this problem along with fspgtd but he didnt have his govenor removed when that happened i dont think. did u try turning back the full load scew cuz that worked for me but i was in a racing mood at the time so i felt it wasn't in my best intrest to turn it back.
anyway i wish i knew what was gin on inside of my pump too so i could alter it some more and get some o more power outta it.
hope this helps some more
Mark
P.S.
i never really tested it with the screw turned out so the throttle doesnt stick so i dont know if it would be fatser or not. i would right now but my car is at my friends house. if you want to know anything just ask and if i kno i'll tell you or if i don't i'll try and test it.
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I haven't tried backing off on the full load screw yet, but I'll try that tomorrow. I just wish it wasn't so challenging to make it work just right. I'm bound and determined to get to the bottom of this though. I've had my car down for the last 3 days and its basically the only thing I've been spending my time on. If I find anything interesting out I'll be sure to post it here for all to see.
Nick
P.S. Kind of funny how nobody else mentions any problems like this with their governor mod. Maybe we did something wrong or failed to do something in addition to what we did. Or maybe we were just born lucky lol.
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I tried backing the fuel screw off, but it only helped a little bit. I thought about it some more and I think I might have it figured out. I took the nuts out and also removed the part load spring. I replaced the part load spring with one of the nuts which was enough to make up for the part load spring and slightly preload the main spring a little more than stock. I have to go to the hardware store to get a hose clamp and then I can try it. I will report back once I see how it works.
Nick
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Let me get this straight: the problem you are currently trying to figure out how to fix is getting the RPMs to drop quicker when you pull your foot off the throttle, yes?
If so... I can offer you the following advise. I've found these pumps develop this characteristic when the full load screw is turned in too much. In fact, if you are experiencing this you are on the verge of having the RPMs not returning back to idle all (but just hanging up there... at 3000rpm or whatever under no load... at which point I would recommend using the clutch and brake pedal to use the transmission to slow down the engine.) This seems to just be a natural limit of the governor. I suspect the flyweights have run out of room and are fully extended, or something is happing like that. But because the full load screw is turned in so far, this minimum setting the governor is able to achieve is not able to move the contorl collar back far enough to drop the engine RPMs quickly enough (or even back down to idle at all.)
The only fix to this that I know of (not saying there might be something else yet to be uncovered... let us know if you find it.) is to reduce the full load screw setting to get the RPMs to drop back down quicker. You can gain back fuel if needbe by modification to the LDA device (which is essentially a throttle stop. So modifying it so say, the control cone moves further away from the feeler needle allows you to press down on the throttle farther.)
A2 injection pumps have an extra adjustment that is called a "residual pressure" adjustment that somehow effects this, although I'm not really sure how it works or if it would enable more fueling.
If you've maxxed out the LDA (keep in mind there is always a custom grind control cone, which combined with more throttle lever motion should give more fuel) and have the full load screw turned in to the verge of the RPMs not naturally falling back down on their own, I think you're just at the fueling limit of the pump at least as far as I know how to adjust them while maintaining driveability. The next stop for more max fueling might be a 10mm plunger or perhaps a larger injector orifice size, or both.
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Thanks for the info. My pump has the atmosperic thing on it, I was wondering if any of the control cone mods would give me more performance. I'm not quite sure being that I have an NA. Hope to hear from you soon.
Nick
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Lemme think on that question... I have an atmospheric control LDA cover sitting in my garage I'd need to take another look at to answer that.
I can tell you that the ATM limiter operates very similar to boost enrichment devices (also known as LDAs.) For sure, since they are just a fuel limiting device (like LDAs) simply removing them (IE: replacing the governor cover with a bare, non-ATM, naturally aspirated style cover) would remove the way that they limit the fuel quantity. But... there might be a way to adjust them for more fuel too... let me get back to you on that.
What are your EGTs - juat realizing now that you've got a NA motor, I've got to ask: are you concerned about overcooking your EGTs are melting pistons by running too much fuel? While it has been tested and shown that a big-exhausted, intercooled TD seems to have a large margin of safety in terms of being capable of having more fuel added while keeping EGTs safe and nothing from melting, an NA motor (unless cammed, ported, etc - something to add more air or reduce EGTs...) would have relatively little safety margin, IE: adding just a little more fuel may cause critical EGT levels.
I would recommend being careful about overfueling, and consider installing a pyrometer if you haven't already so you can see what's going on!
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Well I got it to work finally. Replacing the intermediate spring with something solid seems to work pretty well. It drops rpms a lot quicker than it did, but it still drops them slower than stock. I think I just need to mess with the fuel screw a little bit more. It doesn't seem to stick anymore and it idles fine now too.
FSP I ran the car for a while with elevated fuel levels smoking all over the place, but that quickly got old leaving a cloud everywhere I went so I turned it down where there is only a little bit of smoke at wot. I will adjust the fuel until I can get close to that level again. BTW how would I go about adjusting the lda to reduce fueling? Thats something I haven't messed with yet. I hope to hear from you all soon. I'm gonna go play with it some more and take it for a test drive.
Nick
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Well the test drive went ok, but I definitely need more fine tuning. Power was great in the high revvs. I could peal the tires with ease in first. The only problem now is getting the revvs to drop at a quick enough rate. The revvs also raise quite a bit faster than they did before. Temperature was at the same level as it normally is, though I didn't get to do much hard driving because I had to shift so low. If anyone has any ideas my ears are open.
Nick
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I tried reducing the fueling, but I had to reduce it so far it would almost die on a launch from first. I'm not really sure how to modify the lda cone for more fueling and I didn't want to drive it the way it was so I put the governor back to stock. I would like to get it to work eventually, it just looks like that won't be until I learn a little more and have another free weekend. Unfortunately while tightening the cover down I rounded one of the allen bolt heads. Next time I get to work on it I think I'll replace them all. If someone could explain the how to modify the lda or post a link that would be great. Well I gtg get smarter lol. Thanks in advance.
Nick
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Hey FSP when you talked about modifying the lda for more fuel did you mean just turn the torx with the locknut on top of the pump? If thats all I had to do I really feel stupid now lol. I took the pump apart three times this past weekend.