VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: TDTech on April 21, 2007, 06:24:52 am
-
DELETED!
-
DELETED
-
deleted
-
Deleted
-
Here's some pictures and background reading on a previous discussion about internal pressure and adjusting the regulator:
http://www.vwdieselparts.com/forum/viewtopic.php?t=5936&highlight=internal+pump+pressure
-
I've been rebuilding pumps for 10 years and this "internal pressure" discussion is IRRELAVENT. This mod is a performance mod... not some method to skip a pump rebuild because of a worn feed pump or to fix substandard fuels. It is intended to squeeze more power out of an IDI diesel with a mechanical injection pump, not to restore or change internal pressures. Increasing the pressures to achieve this type of advance would blow the seals out of the pump. Besides, you couldn't increase the internal pressures anywhere near enough to gain the advance that this mod gives you. If you want better acceleration, mod the advance mechanism.
Funny how the story changed from what is clearly a performance mod to "restoring internal pressures" and compensating for ULSD. That was not the theme of my original post, but the replies somehow shifted.... hmmmm Again, the discussion is irrelavent.
It's real simple... you can do it, or you can not do it... nuff said!
Wow a fight...
take it easy mate. For a mechanic with such experience why so sensitive ? sure your spring fiddling will increase advance with no increase in int pressure but your performance mod also mentions an improvement in economy. What Andrew suggests will also give an improvement in an ageing pump. Restoring internal pump pressure just up to factory levels can't be a bad thing and shouldn't blow healthy oil seals.
I put it to you that improvements to economy and performance can also be achieved by those who don't feel confident enough to enter the pump simply by rotating the spaceship diaphragm.
If anyone is looking for improvements in economy as a priority then reducing break pressures in injectors will work (as long as nozzles are running correctly) This goes against conventional thinking but so did Darwin... This might explain why Lucas pumps can achieve 85+mpg imp on a run whilst injectors only operate at 120 to 130bar.
We can all learn more even when we are as experienced as you obviously are. Shame you haven't posted more than your 5 sessions or we'd all be up to scratch on your hidden talents.
Having said that you won't be touching one of my pumps as you appear to be well rehearsed in throwing serviceable pumps away. Is your work commission based?... Oops a little low that blow...
Anyhow keep posting so that the non mechanics here can be helped :o)
-
when Andrew is right... :wink: :lol:
just out of curiosity, what is the internal working pressure of the pump??? i've got one of those solid state pumps with around 4.7 psi. if the actual regulator inside the pump is the problem, then wouldn't the extra lift be pointless since the extra pressure will simply be bled off? or is that how it works?
thanks!
-
As I said before... the regulator is at a FIXED pressure. Of course if you destroy the regulator, then yes you can change just about anything. I still stand on what I said before... the VE pump is designed to run at a certain internal pressure at any given speed. At the beginning of that "how to" it specifically says "Pressure in pump MUST be 43.5 Psi at 1000 RPM engine" which is correct. That's 500 pump RPMs as stated in the calibration manual. The one thing you really don't want to mess with is the internal pressures. it causes premature failure of the seals.
You take a small punch and tap the center of the regulator in slightly to increase internal pressure. Do so in very small increments while measuring the internal pressure.
Wow, such an accurate way to change a critical setting! Yes, it works for a while... until the pump blows a seal. How can you expect something you've damaged to work reliably? Ever think that when you tap in that regulator, you're changing the shape of the piston as well? so now it's going to get stuck sooner or later, what happens then? new seals. why take all that risk?
The spring mod uses VW parts... VW parts that have been installed in other VW's... undamaged. Removing the thicker shim only provides for less spring preload so advance happens a little earlier. The lighter spring was used in the Vanagon as a stock part... so how will the timing be over advanced? I've done literally hundreds of pumps and most are using the green spring with thin shims.... and are still running. Like I said, you can do the mod, or not do the mod... or go ahead and change something Bosch says is a critical setting... it's your time and money to replace the pump. As for this forum... I'm finished here. feel free to destroy your pumps at will... I was giving you a safe alternative.
-
Hey gents... deep breath time... *no one* has a monopoly on the truth !!! We'll all bending these machines much farther than F. Porsche, R. Diesel, and R. Bosch ever intended... and there are always many many ways to peel an onion.
I've learned tons here by listening to everyone's particular point of view, and like everything else on the Internet we all have to decide if what we're reading makes sense for us. There's a ton of practical experience behind the notion of changing the internal pressure, and it also sounds like there's a ton of practical experience behind using stock VW shims and springs to change the advance curve... cool stuff, and not mutually exclusive.
What brings this gang together is a love of wrenching on these beasts and taking them as far as we can... let's keep chatting !!
Vince
-
Alas he obviously had hands on experience...
But his words of the apocalypse commeth for all alternative ideas to his own was a no-no :roll: Smells commission based...
To hijack this thread that is now vacant :shock: ...
Why can't I use vaccuum from the exhauster to run a Cruise Control system? :?:
-
Now, I know little about the pumps, but could the dynamic timing setting from the factory also be emissions influenced rather than performance driven, hence there being some merit to what he said? He still comes across like a knob though. We had a similar guy on a Land Rover forum who knew EVERYTHING better than anyone else. He got pissed off and left pretty quick too. "King Landy", "TD Tech", guess you have to expect it with names like those. :roll:
-
Here the original ''BOSCH'' tool to adjust pressure regulator:
(http://img250.imageshack.us/img250/6928/im001782zf1.th.jpg) (http://img250.imageshack.us/my.php?image=im001782zf1.jpg) (http://img250.imageshack.us/img250/7595/im001783gj0.th.jpg) (http://img250.imageshack.us/my.php?image=im001783gj0.jpg)
And here the description of the BOSCH ESITRONIC software:
(http://i19.photobucket.com/albums/b166/9golf1/pieces%20pompe/avance.jpg) (http://i19.photobucket.com/albums/b166/9golf1/pieces%20pompe/avance2.jpg)
The majority of the IDI pump, the pressure are 0 - 100psi, and for a specific DI pump, the pressure can go up until 160psi, and no seal leak.
To adjust the timing curve, it's more easy with the regulator, and it is conceived has this end.
And for the regulator them even, there exist with different pressure curved, (different hardness from spring, different size of bleed port and 2 or 4 bleed port)
-
It is not because a guy changed only kit of seal on hundred pumps which it know all the real operation of these pumps :lol:
I have a friend who has worked in a shop of refection of pump for several years and it is not able to built a M-TDI pumps :lol:
-
TDTech, it is not your knowledge which is in question, it is rather your attitude opposite this.
If I were done has your first lines, you will learn some here than than you learned on this subject lasting 10years.
A forum it is not a place to claim itself to have infused science, one is here to discuss and exchange our experiment.
-
Hey Limey, What's the "exhauster"? Is it a part near the bonnet or the boot? :lol:
Andrew
[/size]
Hey pump killer ...
It's under the hood :wink:
Funny its called the brake servo vacuum pump in the Haynes and Exhauster in another book that I was perusing; so thats why no-one was willing to do more than view :shock:
-
Does anyone else think that there may be merit to his statement regarding the timing and emmisions?
-
Does anyone else think that there may be merit to his statement regarding the timing and emmisions?
by advancing the timing curve???
-
Absolutely it is true that manufacturers have for a long time had to balance power and drivability with emission legislation.
A long time ago when I was a Beetle guy we clearly saw changes in carb jetting and distributor timing directly related to the legislative environment a particular model of Beetle was sold.... California was a great example of special jetting and a distributor with a *special* advance curve.
Diesel emissions of course don't follow the same math, but I can certainly believe that manufacturer still has to do tradeoffs based on emission standards.
Vince
-
so then the yellow (or green, I forget) spring mod will probably net some nice clean power
-
Andrew, your right on the money. I checked my pump pressure and it was 10psi low. A punch and hammer work fine.....'till you get sick of tapping forever and hit just a little harder, I took mine apart like three times :roll:
After I got the pressure right it sounded like it was pinging to much so I followed hagars advice and retarded the timing as much as I could w/o it shaking. Also rigged a fuel jug up on the passenger floor so I can watch the fuel get drank, kinda depressing, so far barely 10 miles on a quart of diesel. I think I voided my pumps warranty but thats OK, they stink anyways.
-
Hi Mark... not sure what you mean by "exhauster" ?
I know that petrol = gas, boot = trunk, and steak and kidney pie = food poisoning, but that's about it for my knowledge of British ?!! :wink:
If you mean the vacuum pump then the answer is yup.. that's where the OEM ones are driven from actually.
-
Now, I know little about the pumps, but could the dynamic timing setting from the factory also be emissions influenced rather than performance driven, hence there being some merit to what he said?
good point. in my reading of numerous diesel design papers for uni i did come across many correllations between timing advance and NOx emissions.
the VW IDI is ...notorious maybe?.... for being a producer of NOx, a powerful smog creating gas.
the 1.6TD design paper even goes as far to state that in california the vw idi was given waiver from reaching emissions requirements for NOx merely because it was so good in all other areas!
i know for a fact that NOx emissions are hard to get around with IDI diesels whilst still achieving optimal timing setting for bsfc (brake specific fuel consumption).
-
i know for a fact that NOx emissions are hard to get around with IDI diesels whilst still achieving optimal timing setting for bsfc (brake specific fuel consumption).
True, but the trade offs are definitely not proportional. A ~5% reduction in fuel efficiency is worthwhile to see a half or third of the NOx emissions IMO.
-
I'm going to have to think about this, because I'm having a hard time grasping this.
The feed pump is a simple rotary pump. It is always spinning. At low RPM's the pressure regulator isn't doing anything. All the pressure goes straight to the pump. Then when the RPM (and internal pressure) of the feed pump is high enough, the pressure regulator's spring is compressed enough to limit the pressure to that specific point. Above that point the extra diesel is fed back into the intake, instead of the pump.
Where is my logic wrong?
Yes, in part, the regulator is effective at idle + ou -, if it's not properly adjusted, you need to back the initial timing.
Several Bosch VE pump have an electric cold start (advance timing) directly on the regulator.
With an open regulator (for test) the motor can not rev higher than 1200-1300RPM.
On another note, there are a lot of different regulator, you can make a different timing curve:
From idle at 40psi to 4000rpm at 75psi ..........
From idle at 40 psi to 4000rpm at 125 psi.........
There are a lot of combination you can make, a low timing at low rpm is a good help to spool a big turbo, etc...........
-
I cant get my way so I'm gonna delete my posts!
-
Hey guys
being a fully trained Bosch trained tech i can give your conlusive
results on your debates
yes the pressure regualtor, regulates all the time even during cranking
and from all speeds there after.
the vane type pump is always trying to overcome the spring tension on the regulator and when you change the top plug by hitting it with the
punch you are changing the spring tension therefore changing the
pump pressure.
Giles
-
I'm a relatively new to the world of diesels, but I have attached a pressure gauge and photo tach to several pumps on the bench, and I can confirm what Giles just said about the regulator performing its function at all rpm. At low/idle rpm the pressure may not be sufficient to advance the timing, but it is sufficient to make fuel flow through the orifice in the out bolt.
Tapping the plug down with a punch results in an increase in pressure all along the rpm range, not just the 'high' pressure.
There has been mention of 'weak' vane pumps. I'm not sure what was meant, but my experience is that if the vanes are clean and move smoothly in the impeller, they will easily develop 150 psi and good outflow. The first pump I disassembled was rusted tight; I knew I couldn't make it any worse, so I took it apart, hammered the vanes out of the impeller with a punch, sanded the rust off with 400 grit, re-assembled, and later tested it. Even that vane pump produced essentially the same pressure as other pumps when the same regulator was swapped into it.
What I would like to see from some of you who have dynamic diesel timing devices, (or from any source if it's available,) is a useful way to relate pressure to degrees of advance: maybe a table or graph showing the typical advance-to-pressure curve.
-
What I would like to see from some of you who have dynamic diesel timing devices, (or from any source if it's available,) is a useful way to relate pressure to degrees of advance: maybe a table or graph showing the typical advance-to-pressure curve.
Well, there are supposed to be at least 5 different advance springs, and on top of that, all the shims. So there is not going to be just one curve.
-
"five springs, shims: not just one curve"
Yeah, I knew it wouldn't be that simple; never is. Guess I'll just have to get my own dynamic timing device; someday they'll be more affordable. Until then I'll just have to play with the pressure issue. Bugs me just a bit, though, that it's a process that only controls timing indirectly: if the timing advance mechanism sitting in the bottom of the pump gets some piece of crud or gunk and doesn't move properly I wouldn't even know it except if it got bad enough to impact performance/mileage to a noticeable degree, which would probably have to be more than 10%.[/quote]
-
For those which ever seen, here a feed pump:
(http://img98.imageshack.us/img98/429/feedpumpxm6.th.jpg) (http://img98.imageshack.us/my.php?image=feedpumpxm6.jpg)
What I wants to say about different timing curve, look at this pic, there is different spring hardness:
**From idle at 40psi to 4000rpm at 75psi ..........
or from idle at 40 psi to 4000rpm at 125 psi.......**
(http://img137.imageshack.us/img137/4361/springregulatorcp1.th.jpg) (http://img137.imageshack.us/my.php?image=springregulatorcp1.jpg)
The bleed hole are also different size:
(http://img137.imageshack.us/img137/774/bleedportregulateurqx5.th.jpg) (http://img137.imageshack.us/my.php?image=bleedportregulateurqx5.jpg)
Out-Bolt are also in different size, more or less flow trough the pump and that affect the pressure, and there exist an adjustable out-Bolt:
(http://img137.imageshack.us/img137/1342/outboltmm1.th.jpg) (http://img137.imageshack.us/my.php?image=outboltmm1.jpg)
For people more experimented, it is easy to do anything on the timing curve.
-
how can you remove those, i tried but it dont work for me. :cry:
(http://img137.imageshack.us/img137/4361/springregulatorcp1.th.jpg) (http://img137.imageshack.us/my.php?image=springregulatorcp1.jpg)
intrested about the OUT bolt wich is adjustable, where you bought it?
Greetz, Benjamin
-
Out-Bolt are also in different size, more or less flow trough the pump
That may be true, but I've tested five different out bolts on the same pump at the same RPM, and they produced the same pressure.
As far as removing the sleeve in the regulator to get the plunger and spring out, you can take a nail and grind the head eccentricaly to the size that will just fit inside the sleeve; clamp the nail in a vise, push the sleeve over the head, hook the sleeve from the back; it will pull out fairly easily.
-
Hey guys,
i been going through this thread and have not found my answer?
i made a gage to monitor the pressure from my out bolt!
i noticed at idel i'm at 25psi and when it goes up it goes up to 80psi!
now should i increase my idel pressure to 40psi at idel?
any input would be great! it's aTDpump gov,mod and possibly a 8mm head timing is set at 1.05mm prolly will need to change that if i increase the internal pressure? let me know what you think?
thanks Duane
-
Duane: this is the thread to read:
http://www.vwdieselparts.com/forum/viewtopic.php?t=5936
-
so i bring my pressure up to 40psi at idle will do it? am i understanding that right?
Duane
-
so i bring my pressure up to 40psi at idle will do it? am i understanding that right?
Duane
43.5 psi when the engine is at 1000 RPM... yup... or so says the thread. We'd need Bosch's ESItronic to know definitively I suppose. :wink:
-
43.5 psi when the engine is at 1000 RPM... yup... or so says the thread. We'd need Bosch's ESItronic to know definitively I suppose. :wink:
Hellyeah, i searched for that but havent found it yet :cry:
Greetz, Benjamin
-
Playing with internal pressure are a direct effect on the pump timing, but unfortunately to read the internal pressure is a waste of time, it is not the way to adjust the timing.
Can import what pressure at idle it is does not say where are the timing, and not need a gauge to set the correct timing but unfortunately there are no easy way to monitor the timing.
1:bench test with proper tool.
2:Timing lamp but It's really hard.
3:Test road and/or engine noise.
-
My vote goes to "control what we can, and use our best judgment for the rest".
I don't have a test bench but I do have an oil pressure gauge and a tapped out bolt, so adjusting the pump to give the specified internal pressure at 1000 RPM is something I can control.... so I do. Only one variable for sure... but since I can actually control it I do.
Don't have a way to measure the advance curve (just yet!) so I use my judgment... play with the springs and shims.... listen to the engine... take notes... and expect to take 3 steps forward and a couple back every now and then.
-
well i did mine! at idel it increased to 30psi now i see how a tach is important doing this adjustment! i may have went too far? but now it peaks at 130psi!
but the idel sure smoothed out now! i'll watch it this week and see if i notice any milage change?
but you do need to know what RPM your at when adjusting this!
thanks Duane
-
cant still understand the way to do the adapter out bolt...
the screen thing is making me nervous on doing this...
can someone clarify this and show a easy to do adapted bolt to a td pump?
thanks
-
libby, i have read that topic many times...
sometimes say that the hole in the out have to remain the same,others just cut the hell out of it and other left the screen inside...
soooo,where am i? :lol:
-
cant still understand the way to do the adapter out bolt...
the screen thing is making me nervous on doing this...
can someone clarify this and show a easy to do adapted bolt to a td pump?
thanks
the screen thing inside may not bother it if it's not there? just that little hole in the side of the out bolt don't mess with! drill carefully directly on top of the head of the nut! start with a small drill bit! till you get to the size you desire for tapping threads ! if you mess up the screen just make sure you get it all out! your only using this bolt just for adjustments purposes and after your done put the normal one back in! hope that helps?
thanks Duane
-
cant still understand the way to do the adapter out bolt...
the screen thing is making me nervous on doing this...
can someone clarify this and show a easy to do adapted bolt to a td pump?
thanks
the screen thing inside may not bother it if it's not there? just that little hole in the side of the out bolt don't mess with! drill carefully directly on top of the head of the nut! start with a small drill bit! till you get to the size you desire for tapping threads ! if you mess up the screen just make sure you get it all out! your only using this bolt just for adjustments purposes and after your done put the normal one back in! hope that helps?
thanks Duane
clarified :wink:
-
I adjusted my buddy's internal injection pump pressure because he was complaining of low MPG.
Using the Ferret 765 setup with my tach/timing light I saw, even after adjusting, that his pump wasn't advancing.
It just stayed at 12 BTDC,... right near that metal nub to the left of the TDC mark.
sooo adjusting the internal pump pressure isn't the end adjustment but I think it's where to start,.. before playing with springs.