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General Information => Troubleshooting => Topic started by: rabbitman on October 08, 2011, 09:32:05 pm
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So back to tinkering with the '92 golf, for some reason it starts better than it did earlier this summer. Every time though it takes too much cranking and then blows white smoke everwhere.
I just did an experiment, revved to 3000 rpm and pulled the cold start, it clacked more and revved higher without me pushing the go pedal more. It does have the high idle linkage but I doubt it affects higher rpm.
So I think my previous internal IP pressure tests were correct, less than 35psi at...uh....I forgot but whatever rpm is supposed to be 43.5psi...........I think 1000 rpm is the one.
I couldn't get it high enough back then so I think I'll have to pull the IP and free up the vane pump.
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Rabbitman, You stated: "So back to tinkering with the '92 golf, for some reason it starts better than it did earlier this summer. Every time though it takes too much cranking and then blows white smoke everywhere."
Too much cranking to me equals poor glow plug warming or poor timing of IP pump.
Blowing white smoke everywhere to me equals poor combustion due to poor IP timing.
Now you go one to tell us that the IP pressure is low but I can tell you from experience of last week that when I went to start my Rabbit after removing the pressure regulator and getting it to the point where that spring between the two pins would rattle it smoked at first. I shut it off, bumped the pump towards the engine the width of the line on the pulley and it started up just fine without smoke. I did not adjust the pressure at all to this point and I had like zero on my gauge that monitors that pressure. So I don't think the problem lies with the vane pump. You still can generate 35 psi and are. The few extra lbs, yes 43.0 at idle, 750 RPM is what you are shooting for is correct but isn't going to be the difference between smoke and no smoke. The 74.5 lbs is at 2000 RPM.
Once my Rabbit was running I started tapping on the regulator and got it to come up to 37.5 and I left it there. Why? because when I would rev it up it would clearly exceed the 75 lb mark on the gauge. I wanted to drive it on the long haul in fifth and see where the pressure would be. Turns out it is just under 62.5. So I may tap it a bit to get it to bump up a bit under load in fifth.
Revving to 3000 RPM I wouldn't expect the cold start lever to do anything. It is for the extra advance at low RPM's. I wouldn't think that once you have it running that high the cam would be able to move anymore to the advanced side. Maybe there is a problem with the Vane pump in that it only generates a low value of pressure period. Can you tap the regulator down on the front of the pump and get more pressure to register on a gauge? What is the pressure at 3000 RPM. Mine would be near 80. That is what I get when I am running in third and rapping it up to climb a hill that is very long and pretty steep grade coming out of Winchester Bay on 101. They make us slow down to 45 there so I just leave it in third to the top and then up-shift to 5th.
Pressure equals advance on the top end and if you are smoking at the low end first then I would be looking at timing first but if you can't get pressure up top then I would be looking at the pump for a reason why not.
Hope this helps. You have my sympathy on this one, I hate poor performance.
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Rabbitman, You stated: "So back to tinkering with the '92 golf, for some reason it starts better than it did earlier this summer. Every time though it takes too much cranking and then blows white smoke everywhere."
Too much cranking to me equals poor glow plug warming or poor timing of IP pump.
Blowing white smoke everywhere to me equals poor combustion due to poor IP timing.
Now you go one to tell us that the IP pressure is low but I can tell you from experience of last week that when I went to start my Rabbit after removing the pressure regulator and getting it to the point where that spring between the two pins would rattle it smoked at first. I shut it off, bumped the pump towards the engine the width of the line on the pulley and it started up just fine without smoke. I did not adjust the pressure at all to this point and I had like zero on my gauge that monitors that pressure. So I don't think the problem lies with the vane pump. You still can generate 35 psi and are. The few extra lbs, yes 43.0 at idle, 750 RPM is what you are shooting for is correct but isn't going to be the difference between smoke and no smoke. The 74.5 lbs is at 2000 RPM.
Once my Rabbit was running I started tapping on the regulator and got it to come up to 37.5 and I left it there. Why? because when I would rev it up it would clearly exceed the 75 lb mark on the gauge. I wanted to drive it on the long haul in fifth and see where the pressure would be. Turns out it is just under 62.5. So I may tap it a bit to get it to bump up a bit under load in fifth.
Revving to 3000 RPM I wouldn't expect the cold start lever to do anything. It is for the extra advance at low RPM's. I wouldn't think that once you have it running that high the cam would be able to move anymore to the advanced side. Maybe there is a problem with the Vane pump in that it only generates a low value of pressure period. Can you tap the regulator down on the front of the pump and get more pressure to register on a gauge? What is the pressure at 3000 RPM. Mine would be near 80. That is what I get when I am running in third and rapping it up to climb a hill that is very long and pretty steep grade coming out of Winchester Bay on 101. They make us slow down to 45 there so I just leave it in third to the top and then up-shift to 5th.
Pressure equals advance on the top end and if you are smoking at the low end first then I would be looking at timing first but if you can't get pressure up top then I would be looking at the pump for a reason why not.
Hope this helps. You have my sympathy on this one, I hate poor performance.
anything over a high idle, and my cold start lever does NOTHING.. it does make it more marbley when its idling tho..
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Ok answer me this, did you remove the piston that controls the advance? If so did you re install it the correct way? In looking at the pictorials for rebuilding the pump I see a caution to make sure that hole that allows the pressure to enter the cylinder is kept clear.
Just a oh oh moment.
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Maybe there is a problem with the Vane pump in that it only generates a low value of pressure period. Can you tap the regulator down on the front of the pump and get more pressure to register on a gauge? What is the pressure at 3000 RPM. Mine would be near 80.
I think that's the problem, just a bad vane pump.
I tapped the regulator down until it wouldn't go any higher and it still never got higher than about 35 at 1000rpm.
Also I'm not happy with the GP run time, seems like they stay on half the time of my rabbits. And I have a new temp sensor installed.
Once it's started it runs ok, I think it could use more advance though. It starts shuddering after idling very long with the cold start in.
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There you go then, tear into it and let us know. I say three of the four vanes are loose and there is one sticking.
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There you go then, tear into it and let us know. I say three of the four vanes are loose and there is one sticking.
Yeah probably as soon as I get enough time to get it all done I'll do it.
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Well I haven't touched it until now. I pulled (and pushed) it into the shop and letting it warm for a while and then plugging in the block heater for a while it fired right up with white smoke.
Now the weird thing is it smokes white meaning retarded injection, and at the same time it clacks really loud......what could it be?
I plan to pull the IP apart and check for stuck lift pump vanes since the pressure won't get above 35psi.
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White smoke means it is not firing somewhere. That may be the clacking you hear, a crapped out injector. It could just be that the final pressure to the injector isn't very good either or the injector is worn or sticking.
Have you cracked the nuts on the injectors when it is running to try and find the one that is amiss? Check valves at the back of the head fouled?
I would be ripping that pump apart for sure.
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Well I just fired it up and cracked the injectors one at a time and they all had the same affect, less clack and a very even miss.
With the cold start pulled it runs fine, it just clacks worse than I thought it should. It's also very gutless.......
As for the lack of power, it might just need to be driven. My rabbit was so weak at first (after sitting 12 years) it couldn't get out of it's own way, I almost got stuck in a inch of mud just because it could hardly turn the tires ::), now it's got torque enough that I can let the tires spin and get out and push if I get stuck. I did it once in mud up to the rims in the front.
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So pulling the cold start does duel duty on your 92 Golf correct? It not only bumps the idle up but also bumps the timing. Clack at cold is somewhat normal for my 81 1.6 N/A. Once it gets even slightly warm the clack goes bye bye.
I am going to venture a guess that the timing is fouled up. But even fixing that isn't going to fix your problem. Why? Because you need a good working pump to be able to get a good time on the engine. I just don't see you having success here unless your pump is on square.
Since it is now out of the elements have some quality time with that IP.
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So pulling the cold start does duel duty on your 92 Golf correct? It not only bumps the idle up but also bumps the timing.
Since it is now out of the elements have some quality time with that IP.
Correct, timing and idle are bumped up.
In the process now, tomorrow when/if I finish I should have (hopefully) good news. I just put new bushings in my rabbits IP which requires complete disassambly so it's fresh in my mind and shouldn't take too long.
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So tore it apart.........
None of the vanes were even close to stuck. :(
Overall it's really nice looking inside but one thing that concerns me is that the camplate rollers shafts appear to be rubbing the inside of the IP housing, there are four markes worn into the housing deep enough to feel.
When I wiped the inside of the IP with a paper towel it came out greyish black like aluminum dust and I can see where the roller ring has been rubbing the housing.
So the lack of pressure is not the vane pump, I changed the O-rings on the regulator last summer with no affect. Maybe I'll try the regulator out of my parts IP. This is a good time to put green O-rings in it before it starts leaking everywhere.
If anyone has a suggestion it would be greatly appreciated.
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Check valves OK?
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Check valves OK?
Are you talking about the delivery valves? I just ran out and tried blowing through them with my mouth and two almost felt like they weren't a perfect seal but maybe my mouth was leakin' a little.
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I'm thinkin' maybe this shows why the pressure isn't getting high enough.
(http://i249.photobucket.com/albums/gg218/rabbitdude82/dsc05391.jpg)
That sleeve on my rabbits pump doesn't have them holes, the golf does, the holes are to leak off pressure at certain loads/rpm to change the dynamic timing. As the sleeve slides on the guide holes line up and let pressure go or else seal and let pressure build.
Now I just have to figure out if mine's working properly........
Also the governor shaft on the rabbit has backward threads while the golf has normal threads and a normal nut.
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Well I put it together and it still runs about the same.
I haven't messed with the timing at all though.
It's still blowing white smoke unless I pull the cold start and then it still misses too often and every 5 seconds or so it clacks real hard, maybe the injectors are junk even though I just pop tested them not to long ago.
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Yes on the check valves on the back of the pump, the delivery tubes connect to them. My thinking is that there is only a small amount of fuel that actually gets "pumped out" to the injectors. That fuel joins up with other previously delivered pumps and the entire tube is filled clear to the injectors. When more gets shoved in from the pump it is then forced out the injectors.
If the delivery check valves are bad and let this column of fuel leak back into the main pump some then the total pressure to the injectors is less than what would be needed to get good delivery and atomization into the cylinders. Short a bit on both fuel and pressure. You say you pop tested them and they were good. What about checking delivery by hand cranking the IP pump. Or turn it with a variable speed drill.
If the rest of the pump inside is good as you say and the vanes aren't hanging up then I am now moving my thoughts to the final delivery points. Although I still say your pressure at idle is low. 40-42 would be better than 35.
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Well I put it together and it still runs about the same.
I haven't messed with the timing at all though.
What exactly do you mean by this? You are setting the IP timing with a dial indicator, right? What do you have the timing set at? 1.05 or some other other number?
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What exactly do you mean by this? You are setting the IP timing with a dial indicator, right? What do you have the timing set at? 1.05 or some other other number?
So far all I've done it lined up the marks for installing the belt on the right tooth and it runs but I can tell the injection is late.
I don't have the proper dial indicator and it's a real chore using the one I have so I just go by ear. I've used a dial indicator before and didn't like it anyways, can't remember what way I retimed it but I changed it by ear and had better performance and mileage.
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Actually the dial indicator is quite easy to use. You pull the plug in the back of the pump and screw it in. You do not have to remove anything else. W/O the timing tools you are just chasing your tail. They are only about $53 complete off of the interwebs, so there is no excuse for any diesel guy not having one. It will make your life much easier.
Until you can lay your hands on the proper tools, find a big hill and use the Swedish dyno. Make a couple baseline runs and then start advancing the timing in very small increments and see if it gets better. If not try the other way until you find the sweet spot.
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Toby, I find it very ironic that you call this method the Swedish dyno, They are some of the finest makers of precision equipment in the world. But I guess if you don't have the tools the terran will work for you too. Does it have to be a hill or will any flat distance that you can time to work?
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Does it have to be a hill or will any flat distance that you can time to work?
With flat ground shifting at different rpm or missing a shift will change the outcome and the test won't be totally conclusive.A hill is just hold it to the floor and see how much speed you gain or loose.
Actually the dial indicator is quite easy to use. You pull the plug in the back of the pump and screw it in. You do not have to remove anything else.
I've used the correct tools before so I know how to use 'em but I no longer have access to them. The dial indicator I have is a universal type with clamps and all different ways to mount it, I used it once and it took forever to get it clamped in the right place and steady enough to actually use.
If I could buy just the dial indicator for way cheaper I would since I don't need the cam or IP lock
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http://zdmak.com/wbstore/main.asp?action=PROD&PROD=VW2066WH&CTMP=1&LowCt=0 ;D OR
How about this set for a few bucks less. http://zdmak.com/wbstore/main.asp?action=PROD&PROD=MK-4033SET&CTMP=1&LowCt=0
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Does it have to be a hill or will any flat distance that you can time to work?
With flat ground shifting at different rpm or missing a shift will change the outcome and the test won't be totally conclusive.A hill is just hold it to the floor and see how much speed you gain or loose.
In addition you can do flat out runs from a dead stop on a hill and not have to break the speed limit. Not always important but if you are making 5 or 10 back to back runs while you are making timing changes, its nice to know you won't be risking a ticket. The hill also increases the the speed differences over a flat road. At least on a short (<1/8 miles) runs.
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I've used the correct tools before so I know how to use 'em but I no longer have access to them. The dial indicator I have is a universal type with clamps and all different ways to mount it, I used it once and it took forever to get it clamped in the right place and steady enough to actually use.
If I could buy just the dial indicator for way cheaper I would since I don't need the cam or IP lock
Try these guys. $53:
http://www.ebay.com/sch/sis.html?_nkw=VW+Diesel+Injector+Pump+Timing+Gauge+Tools+Injection
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That's prothe, a much talked about guy that was here for a while until he kinda got ran off (nobody told him to leave though) since he wouldn't disclose who/where his stuff was made.
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Forgot to consult the many names of Prothe list before posting. Man that list is long.