VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: levi20AE on January 06, 2010, 09:28:24 pm
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Tonight I measured and adjusted the pump pressure.
After 5 adjustments I left it alone. I did not notice a change in idle or sound after any of the adjustments. It does seem peppier in the upper RPMs and no noticeable increase in smoke, so overall I'm happy. I am worried that maybe my pump is dieing or just getting wore out. As you can see the slope of the lines in each of my measurements after incrementally increasing the pressure were the same. The slope is no where near as steepaswhat is documented in previous post on this thread though. Is this a bad thing? It looks like it but the truck runs great and still does 70 mph or 75 if i really want to push it.
(http://i26.photobucket.com/albums/c112/leviplies/InternalPumpPressureTest01-06-10.jpg)
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I wasn't dedicated enough to make a cool graph, but mine was kinda wonky too. Trouble I had was to get the 1K pump RPM setting right for instance, it'd be over pressure at 500 and 750. I just flat attribute it to a worn lift pump. Coupled with the fact that when setting pressures one is going on faith that the system is working unless they can actually measure the dynamic advance(which I can't).
I pretty well set it about on at 1K and said to heck with it. It's been my experience that with VW diesels in general they will continue to function reliably for a long time after they are quite a bit out of book spec in most respects.
One day I'll replace the lift pump dealy in one of these things and see what happens.
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Interesting - I wonder if the shape of the graph can be credited to the difference between 1980's diesel fuel and what we have today?
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Interesting - I wonder if the shape of the graph can be credited to the difference between 1980's diesel fuel and what we have today?
Do the same test, only add some 'thickener' such as cannola. Perhaps run both fuel lines into a test bottle. One would think that the gradient would steepen.
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As long as this isn't way out of reasonable results I'm happy. I did notice that it started easier and the general noise that a diesel makes on a cold morning went away faster this morning. Still haven't noticed more smoke or it idling any louder. It does idle at 1000rpm though, should that be reduced?
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If you can lower the idle without the car shaking apart then you may as well. I run my car at 1000 RPM idle because of "other issues" with the car
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Cool Graph! ;D
Unfortunately the 1st Red measurement line looks bang on the money for a 1984 1.6td. IF I deciphered the bosch page right http://www.vwdiesel.net/forum/index.php?topic=19692.msg149187#msg149187 (http://www.vwdiesel.net/forum/index.php?topic=19692.msg149187#msg149187)
I pasted on a graph the various pressures quoted, and they were parallel to the pressures I got on my pump.
That black line looks like Hagars 107 pump, but my guess it is too fierce.
http://www.vwdiesel.net/forum/index.php?topic=22316.msg175042#msg175042 (http://www.vwdiesel.net/forum/index.php?topic=22316.msg175042#msg175042)
Originally I set the timing with too much advance, When I pulled the injection nozzles, they had gone a sky blue temper colour. Suggesting thet got way too hot. Hope I'm not the messenger of bad news. :(