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Internal IP pressure again.
by
rabbitman
on 08 Oct, 2011 21:32
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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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#1
by
ORCoaster
on 09 Oct, 2011 11:53
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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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#2
by
R.O.R-2.0
on 09 Oct, 2011 12:08
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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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#3
by
ORCoaster
on 09 Oct, 2011 20:49
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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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#4
by
rabbitman
on 10 Oct, 2011 18:06
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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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#5
by
ORCoaster
on 10 Oct, 2011 18:23
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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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#6
by
rabbitman
on 11 Oct, 2011 11:52
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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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#7
by
rabbitman
on 17 Nov, 2011 17:52
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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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#8
by
ORCoaster
on 17 Nov, 2011 18:51
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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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#9
by
rabbitman
on 17 Nov, 2011 19:12
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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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#10
by
ORCoaster
on 17 Nov, 2011 19:45
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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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#11
by
rabbitman
on 17 Nov, 2011 19:55
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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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#12
by
rabbitman
on 18 Nov, 2011 13:43
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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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#13
by
ORCoaster
on 18 Nov, 2011 14:41
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Check valves OK?
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#14
by
rabbitman
on 18 Nov, 2011 15:17
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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.