kwik, what is the cost of the vw pump and where did you get it?

Good Job!

 

Thanks for the info! I've filed it away for (near) future reference.

 

I bought it from one of the warehouses that I buy from: Interamerican Motor Corporation. IMC.
Price I don't really want to say, it's a wholesale account.
World Pac's list price is around $183.00

 

I did a search, and came up with a few results. Napa online has 2 different pumps, don't know the make, but both are rated at 56GPM 73psi. One is $131.99, the other is $102.99. I've always had good results with Napa parts, I know there not Bosch, but probly Carter. Any thoughts on these? Oh yeah, our pumps through Napa costs $203.49

 

any part numbers on these two pumps, or where these the ones kwik listed.

after this find I can see my full electric conversion happeneing REAL soon.

Diesel Rod

 

Kwik,

Why the necessity to remove the VW "check valve" at all?

Also, this fitting "adaptor" is going to be tricky, doncha' think? Maybe that banjo bolt may be the way to go. Are they VW or Bosch parts?

Since the old pump was still pumping, how much of it's loss of volume (and thus pressure when the real flow demand started) would you attribute to a clogged input? After you removed the teaspoon of "gunk", how do you think the pressure would have "held"?

I believe a simple in-line pre-pump filter should be very high on the list of things to add to even stock trucks. Who knows, if you had one before-hand, you may not have gone through this exercise and expense. Just a small, $5 filter to change.

There's a lesson here for folks with stock fuel systems.

Pop

 

I wanted as much volume as possible and the check valve would have been a restriction, however small. Besides, the PSD wasn't designed to have one. And I didn't have the proper cap nut to attach the fitting to the pump. I did have an ample supply of banjo bolts, so the course of action to take was obvious.
Can't answer your pump volume question, the old one was out by then and it wasn't going back in for any reason.
Yes, everyone take note on a pre-filter. My pump wasn't worn out, it was clogged up. A $5.00 filter change whenever you change your oil is a LOT cheaper than replacing the whole pump.

 

The fitting adapter would be a piece of cake if one could be found with the proper threads. I'll report back on that on Monday after I measure the threads. One is course and the smaller one is fine thread.

 

Part numbers are listed in post # 12 of this thread.

 

Unless you got a bad load of really dirty fuel, I'd venture to say that a reasonable change interval for even a small filter could be around 25-30K miles. All you're really doing is filtering out the stuff that won't already pass the pump's inlet. The smaller stuff that passes will get filtered by the regular fuel filter.

Of course, more often won't hurt anything but the back pocket, and then, not very much.

Pre-pump filters, guys. Saving you some real bux in the long run. Maybe the PSD's Bosch pumps are also designed for 20 years? Who, besides Bosch and Ford engineering, knows the MTBF?

Pop

 

My stock pump has a check valve in it.

Plugging of the pump screen is why all the in-tank mod kits strongly advise the installation of a pre-pump filter.

 

Are you sure about that? The one that came out of my truck has a straight out tube - nothing else.


When I did my Hutch mod, I re-used the pickup screen, put it back in the tank in the same position as the factory installation. I blocked off the air gulping side port with the steel line. The only route that my fuel takes is through the pickup screen.
This is the original fuel pump on my truck so I am sure it's six years of accumulation building up.

You know gentlemen that there are other Bosch designs out there that go even farther than a simple pre filter.
1986 Golf, Jetta, GTI, for instance have a transfer pump mounted in the tank that pumps fuel to a small chamber that holds about 1/2 gallon. From there the fuel is pressurized and pumped to the engine at 73psi system pressure. They control air/fuel ratio by using what's called "working pressure". On a cold engine the working pressure is much lower than the system pressure and has a greater differential so more fuel is injected. As the engine warms up working pressure is increased so the amount of fuel injected goes down and the fuel/air mixture leans out. It's called Bosch KE Jetronic. I'll try and dig up some teaching materials that are similar to what I learned when I went to school about it. It's a VERY ingenious system that works flawlessly for the life of the engine as long as no dirt gets in. The fuel distributor has a plunger with 4 microns clearance between the piston and the cylinder walls that it fits in and floats on the film of gasoline.

 

For those of you interested in the design of the Bosch K Jetronic.
What I called "working pressure" is called "control pressure" as well.
This one has the clearest pictures and a very good explanation of how the fuel pump operates.
http://www.auto-solve.com/mech_inj.htm

This one touches more on KE jet, with integration of the oxygen sensor for more precise air/fuel ratio control.

http://ffp-motorsport.com/tuning/kejetronic.php

http://www.xs4all.nl/~master99/slc/gif/k_e_jetronic/k_e_jetronic.htm

Ok, NO MORE, this is a diesel forum.

 

Been running this pre-pump filter for a while.

Copy and paste the link or it goes to Haven.

http://community.webshots.com/photo/308572756pDZqQb

 

Yeah, that's the ticket! Did you buy the flange at NAPA as well?