Author Topic: Bosch injection pump parts interchangeability?Best combination?  (Read 5789 times)

November 27, 2012, 09:09:23 am

srgtlord

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Bosch injection pump parts interchangeability?Best combination?
« on: November 27, 2012, 09:09:23 am »
At the moment I have 3 bosch pumps. One is an early rabbit pump that has wiped out shaft bushings from yours truly tightening the timing belt too tight. The second pump is a late style NA pump  I pulled off the car but it had a very worn out throttle shaft bushing and dribbled diesel everywhere... The third pump is also a late style NA pump I pulled apart, resealed, lost the orientation of the throttle lever and never tested. Now lets have a discussion on what parts are interchangeable between the  pumps and what the opinions are on what I should do.

Reply #1November 27, 2012, 11:59:32 am

vanbcguy

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Re: Bosch injection pump parts interchangeability?Best combination?
« Reply #1 on: November 27, 2012, 11:59:32 am »
Run with the late resealed pump.  It isn't the end of the world to sort out the throttle setting again, just a little bit of a pain.  

If you have another similar pump around then just adjust the "unset" one to be about the same as the working one - that will get you probably within a spline.

As far as swapping parts around, lots of stuff can be swapped between the pumps but you aren't going to gain anything unless you are replacing a broken part.
« Last Edit: November 27, 2012, 12:01:54 pm by vanbcguy »
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #2November 27, 2012, 01:10:11 pm

8v-of-fury

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Re: Bosch injection pump parts interchangeability?Best combination?
« Reply #2 on: November 27, 2012, 01:10:11 pm »
As far as the lids go, there are quite a few different pieces that play a deciding factor here.

Some have different length throttle shafts, which means a different spring setup. Some have a non-removable governor from the internal throttle lever.

I also suggest running the resealed late N/A pump. I say this because it is resealed, has the throttle bump on the cold start (awesssseoommme function when cold) and does not require any further work ;).

Here is how you can set it up and it will work every-time. Plus it will also be a setting for the most fueling (a.k.a powahh). With the throttle lever and springs off, rotate the throttle shaft as much CW as you can to its furthest most relaxed position. Install springs and throttle arm. Back the idle set screw ALL the way out. Install on to car and fill it as best you can with diesel, as well as the filter and the lines. In fact probably best to run it off an IV of diesel from a jug up higher than the pump. Now at this point, it should not want to catch. Perfect. After the cranking and cranking to bleed the injector lines, and you start to get smoke out the tail pipe. (Have a running jumper vehicle or a jump start battery charger handy..) Start cranking in the max fuel screw until it catches. You should only go 1/8 turn at a time, but it can get lengthy. So like half to three-quarter turns at a time. If and when it catches it will probably run up the rpms. Turn the key off immediately and be prepared to dump the clutch, i've never had to yet.. but be prepared. Back the max fuel out until it does either just fire, or tries to catch on. Turn in the idle set screw to get a good idle. Voila.

Its a lot more complicated in words, but in practice.. pretty damn simple :)

Reply #3November 30, 2012, 04:55:03 am

srgtlord

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Re: Bosch injection pump parts interchangeability?Best combination?
« Reply #3 on: November 30, 2012, 04:55:03 am »
I had issues re installing the double spring setup the last time I had the pump apart. Is there some trick to this? Also does anyone have a picture of how that small divider plastic peice is suppose to sit between the 2 springs?

Reply #4November 30, 2012, 06:28:33 pm

EcoTX

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Re: Bosch injection pump parts interchangeability?Best combination?
« Reply #4 on: November 30, 2012, 06:28:33 pm »
I had issues re installing the double spring setup the last time I had the pump apart. Is there some trick to this? Also does anyone have a picture of how that small divider plastic peice is suppose to sit between the 2 springs?

I definitely feel you there, it is the most god awful PITA getting those springs on.
Some earlier pumps it is very easy, but the later ones with 2 springs it is a chore.

I've just been running with one spring on my pump the last year or so with no issues.
I actually like the throttle feel a lot more with just one spring.
It's not SAE compliant, but it works...

Reply #5November 30, 2012, 06:37:54 pm

745 turbogreasel

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Re: Bosch injection pump parts interchangeability?Best combination?
« Reply #5 on: November 30, 2012, 06:37:54 pm »
Is there some trick to this?
pull the throttle shaft mostly out of the lid, hook it on, and pull the shaft up into place as you lower the lid is what I do.

Reply #6December 01, 2012, 10:50:05 pm

vanbcguy

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Re: Bosch injection pump parts interchangeability?Best combination?
« Reply #6 on: December 01, 2012, 10:50:05 pm »
A wise man on some forum or another told me to use a loop of wire to pull the spring tight and then use that to hook it over the lever.  It works great!!
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen