-
#15
by
92EcoDiesel Jetta
on 11 Oct, 2011 06:56
-
There seems to be various numbers thrown around as to what the internal IP pressure should be. Does anyone have the official Bosch spec for it?
So far, I have a gauge hooked up to the out bolt pedestal and I have 2 regulator bolts to play with. They both measured 30 psi at idle of around 1000 rpm. I pulled both regulator bolts out and replaced the o-rings on both of them and installed only one so far and noted the pressure is now 20 psi (from re-newing the o-rings). I tapped on the regulator bolt while the engine is idling while watching the gauge and got it up to 50 psi at 1000 rpm. I have to take on for a road test.
-
#16
by
Mark(The Miser)UK
on 11 Oct, 2011 09:02
-
There seems to be various numbers thrown around as to what the internal IP pressure should be. Does anyone have the official Bosch spec for it?
So far, I have a gauge hooked up to the out bolt pedestal and I have 2 regulator bolts to play with. They both measured 30 psi at idle of around 1000 rpm. I pulled both regulator bolts out and replaced the o-rings on both of them and installed only one so far and noted the pressure is now 20 psi (from re-newing the o-rings). I tapped on the regulator bolt while the engine is idling while watching the gauge and got it up to 50 psi at 1000 rpm. I have to take on for a road test.
Who's throwing numbers around? Never seen Bosch numbers. They are hidden in their microfische and unobtainium.
Apart from Hagar's claimed figures for the 107A, the most accurate, and based on 23 TD pumps averaged, is the scatter diagram fig 46, on the SAE paper #820441 about the 1.6TD design.
My figures are the best anywhere in the public domain. Period!
I averaged the scatter diagram to create a reference plot to compare and contrast, Hagar's corrected figures, 'My pump' and someone called Levi's... Do a search...
-
#17
by
rabbitman
on 11 Oct, 2011 11:47
-
Forgot about this thread, I thought I had something about this already.
Tried starting again last night, temp slightly below freezing. It was a no go, fired quite a bit but couldn't get spinning.......even blew some perfect smoke rings haha
. Battery's charging now.
-
#18
by
92EcoDiesel Jetta
on 11 Oct, 2011 14:13
-
Thanks good to know. I've been looking for the tool to fine-adjust it, but most diesel shops don't have it, or only sell it as part of a master kit that costs close to a grand. No thanks.
I just need that tool, and a good computerized advance tach timing light. I've got the piezo pickup transducer already. I'm kinda pumped to try all this, because my MPG blows (38 in a Rabbit Pickup). If I can get it to 43+, I'd be happy. Rebuilt the pump myself, but obviously, it needs calibration.
There's a lip at the bottom of the regulator bolt's head where you can make a tool to hook onto that lip like a "puller", by advancing the puller screw. you can fine adjust the pressure. However, with a long punch and a hammer and watching the gauge while the engine is idling tapping on the center of the bolt, you have pretty good control increasing the pressure by tapping with a hammer. At least that was my expereince using a hammer and and 10" extension on a 3/8 drive allen head driver bit as the punch.
-
#19
by
Powered by Spearco
on 11 Oct, 2011 15:34
-
-
#20
by
Mark(The Miser)UK
on 11 Oct, 2011 15:34
-
Thanks good to know. I've been looking for the tool to fine-adjust it, but most diesel shops don't have it, or only sell it as part of a master kit that costs close to a grand. No thanks.
I just need that tool, and a good computerized advance tach timing light. I've got the piezo pickup transducer already. I'm kinda pumped to try all this, because my MPG blows (38 in a Rabbit Pickup). If I can get it to 43+, I'd be happy. Rebuilt the pump myself, but obviously, it needs calibration.
There's a lip at the bottom of the regulator bolt's head where you can make a tool to hook onto that lip like a "puller", by advancing the puller screw. you can fine adjust the pressure. However, with a long punch and a hammer and watching the gauge while the engine is idling tapping on the center of the bolt, you have pretty good control increasing the pressure by tapping with a hammer. At least that was my expereince using a hammer and and 10" extension on a 3/8 drive allen head driver bit as the punch.
That seems a good method.
Possibly a better one is simply a M5 or M6 bolt with a nut on it as a depth gauge/depth stop, when used as a punch...
-
#21
by
Mark(The Miser)UK
on 11 Oct, 2011 15:52
-
Does any one remember this info and would it help?
http://www.vwdiesel.net/forum/index.php?topic=19692.0.
Funny thing that, I already had it rotated on my screen earlier on ACDSEE.
Not easy to decypher.
How does the measured internal pressure have a range of values and not a single figure for each rpm reading? Or is this not a client's particular results, but the general spec? 
I'll give it a good read again.
-
#22
by
92EcoDiesel Jetta
on 11 Oct, 2011 17:07
-
I called a diesel injection shop and asked what the internal pump pressure should be for my pump 0 460 484 027 and was given these numbers:
5 to 5.5 bars (72.5 to 79.7 psi) @ 2500 RPM (engine ). This translates to 32 psi at 1000 rpm (assuming pressure is linear), which was what my regulator was at before I started messing with it!
-
#23
by
Mark(The Miser)UK
on 11 Oct, 2011 18:56
-
The data on the spec sheet for the pump pressure nestles directly below the SAE real pump averages. Smack on where I changed my pressures to.
Note the impossibility of following Hagar's 107A values, by his 'Desciples'
The SAE paper dates from a little after 1981.
Funny how Bosch specs for this pump dropped the internal pressure a few psi, compared to the SAE average of 23 contemporary pumps.
Here is my graph again for reference:
-
#24
by
ORCoaster
on 11 Oct, 2011 19:25
-
Looking at these idle and 2500 RPM numbers makes me think mine might be a tad high and that may explain the little bit o marble sound I have at just off idle. I have gone to watching the psi of the IP gauge as kind of a shift light. Mine doesn't have one but it seems that when i hit 75 lbs of pressure the shift is just about right on the level surface. Going to run it that way for a bit and see what the mileage does.
-
#25
by
Mark(The Miser)UK
on 11 Oct, 2011 19:49
-
Note that Levi was 'on the money' with his second iteration, but went on to excessive pressures in a mistaken belief [like many] that the 107A pump was the standard spec to aim for.
Also note my pump was right down the bottom of the graph when I first checked it, yet it operated linearly. With the right soft spring we could all operate down there and the leaking pump seals would be a thing of the past...
-
#26
by
ORCoaster
on 11 Oct, 2011 21:19
-
I did notice that my engine ran fine with a bit of advance with the gauge showing 10 lbs. I think on revving it up the pressure only topped out at 25. So yes it will run but I wonder how well? Yours pull OK under a hard load? Mileage acceptable?
I think the pressure could be a little less than the oft quoted 43 lbs at idle but just how much less we shall see. I knocked mine back and am watching for changes to the overall performance. Mileage is one thing, drivability is another. I can't be in everyone's way getting 60 MPG.
-
#27
by
92EcoDiesel Jetta
on 12 Oct, 2011 06:55
-
The data on the spec sheet for the pump pressure nestles directly below the SAE real pump averages. Smack on where I changed my pressures to.
Note the impossibility of following Hagar's 107A values, by his 'Desciples'
The SAE paper dates from a little after 1981.
Funny how Bosch specs for this pump dropped the internal pressure a few psi, compared to the SAE average of 23 contemporary pumps.
Here is my graph again for reference:
Is this the pump spec sheet (below pic) you're referring to? If I'm understanding correctly, that is a spec for settings of a Bosch test stand for one particular injection pump. Does anyone know which pump that spec sheet is for? Internal pump pressure is not the same on all VE pumps from what I was told.
-
#28
by
mtrans
on 12 Oct, 2011 12:10
-
My figures are the best anywhere in the public domain. Period![/color]
Mark I DO belive you.
-
#29
by
Mark(The Miser)UK
on 12 Oct, 2011 14:50
-
My figures are the best anywhere in the public domain. Period![/color]
Mark I DO belive you.
I've just chased those numbers on that Bosch paper literally all round Eastern Europe, Europe and back to America, where I found they translate into a 1984 1.6TD ... Jetta. Thus I was correct, Bosch did lower the internal pressure of the pump from the first 1.6TD's
This shows the truth being, that Bosch, just like lots of other Co's were experimenting and learning as they went along...
A big question:
How long does it take for a pump to fill a piston chamber, and does vaccuum play more part than pressure?
