No Fuel Out Checkvalves

[ORCoaster]

I marked them prior to removal but the nondelivery of fuel prior to me taking the top off was the initial issue.  I tested the levers after reassembly and all seems to work according to the look of things.

[burn_your_money]

If you completely block off the delivery valve hole (on the pump head) with a gauge there can be enough pressure generated to crack the pump head. It's a positive displacement pump and that fuel needs to go somewhere.


Just to clarify, your pump was not delivering any fuel out the check valves so you resealed it and at the same time replaced the head, rotor and control sleeve? You now have the exact same problem.

[ORCoaster]

Tyler,  No that was not the case.  The pump was working and the Rabbit ran fairly well before I got to it.  It was leaking fuel out the back of the pumpcase, the cold start lever and possibly the upper gasket under the accel levers.  What I did was purchase a seal kit and start replacing those that leaked.

In my efforts to get the back of the pump off I ended up breaking the shaft so I had to purchase a new pump and shaft from an unnamed parts place on the net.  You guys dis him.  Didn't know that then.  But his tech help person is corresponding with me so maybe you folks changed that for the better. 

So my running pump got new seals and a new pump and now it is not giving me fuel out the distributor block.  The main shaft moves in and out about the 1 mm it should but the final pressure will not open the check valves. 

I have fuel coming in from the filter and out through the outlet to the tank and it is as clear as it can be, no bubbles.  Could the new pump I purchased be defective?  Ever hear of that? 

What pressure should those check valves see from the high side of the pump?  And should they open at 30 PSI as listed above?

[Vincent Waldon]

Ah, if your distro block and plunger are new, and are being fed fuel but unable to generate enough pressure to overcome the delivery valves... a function that demands extreme parts precision and tight tolerances... yup, I'd suspect your new parts.... even if I didn't know they come from a vendor who's parts have a track record of being challenged from a precision perspective 

[rallydiesel]

Yeah, that's probably your problem right there. The problem with getting a new rotor and plunger is the shims are now all out of spec. Such as the shim between the cam plate and plunger and the springs as well. You really have no idea if the plunger and head were ever meant to be used in that particular pump. You could probably get it to work but it will take a lot of rebuilding and tearing apart the pump. You would have been much better off finding a core Bosch pump and using the parts off that.  

[ORCoaster]

Ah HA,  So I am not brain dead!  Well don't ask the wife about that just yet.

This was my conclusion:  That some tolerance must be out of whack, and I specifically asked the tech about the possibility of the little washer being worn and thus not providing enough or to much slack in the system.  I have to remember grampas work in the machine shop.  If it is a Bosch it better be correct.

So why do they sell these parts individually if there is little chance of them working in a used unit?

My recourse at this time is to send it back as it is worthless to me for my purposes, that ought to be entertaining.  Returns, refunds and customer satisfaction are all tied into one bundle and like the pump the tolerances are pretty fine.  I will let you know if I succeed or they tell me differently.

Thanks for helping out on this.  I guess I just threw caution to the wind and jumped in the middle of something deeper than a 2 foot hole.  Be more cautious next time, I will.  And you folks help with that.  You have become a nightly read for me. 

Keep up the good work and helping not only me but the host of others out there as well. 

Later DAS

[fatmobile]

Accelerator lever on the right splines?

Hey this guy had a good question.

[ORCoaster]

Fatmobile, are ya burnin WVO?  My son's rabbit was hooked up that way and the backyard stunk of fry oil for years after he moved out.  In fact I was digging around a few months ago and stirred up a stink of it in the gravel where the 55 gallon drum was located.

But to answer your question I didn't move the levers until after I started having the no fuel situation.  By that time I was using hints and tech help that caused me to have to pull the governor cover off so I made sure I scribed the levers and the shaft to be sure it went back the way it came apart.  Only two springs and two levers on this one.  I didn't see an internal spring under the cover as described on this site elsewhere in the pictures and writeup on how to rebuild a VE pump.  I have discovered what the VE stands for now.  Very Expensive Virtually Endless.

I think I got the levers on OK.  Looking through the banjo port things do move but only a little.  My guess is that is all they need to move to control that massive amount of Bunny Power.

You do make the rounds on the forums do you not?  I guess if I was surrounded by corn in IA all day I would be netting a bunch as well.   

[ORCoaster]

Here is what I have from the tech I am corresponding with:

With the delivery valve in, fuel pressure out of the rotor should be at least 155 bar / 2247.5 psi.

If you are not getting that pressure it’s not enough to open the injector.

Actual pump internal pressure is around 60 PSI. Could be the feed pump is bad or not installed correctly.

 

So I guess it is RMA time!   Joy of Joys!  Nice he sent me some numbers and that they verify my first stage is OK.

[fatmobile]

Set that shaft on a different spline,... or turn the max fuel screw in before you try anything difficult.

I do burn some vegetable oil, but don't manage to get it all over the place and do have a burn barrel for oil rags, etc.

 I do get around to a few of the vw forums, have been floating down the river on a tube lately.

 Surrounded by corn and beans don't forget the beans.

 Tomatos are coming on strong and all my cabbage-loving friends are well taken care of.

[ORCoaster]

I did run the fuel adjustment screw all the way in at someones suggestion.  Maybe the tech I was working with.  How do they say that? NO JOY. 

I might move the lever to a different spline just for the test.  Ya never know, sometimes it is the minor not major tweaks that make a difference. 

If I don't get any results I have the permission to send the part back now.  So the pump gets pulled apart anyway this weekend. 

Enjoy the corn, beans and cabbage.  Just not all at one time, otherwise your "friends" may take notice.

[kingler5]

The usual cause of no fuel out the high pressure end other than a trickle in my experience has been when I mess up getting the control collar hooked up correctly...just another thought.

Can you expand on this? I think I am having a similar problem, only all of my pump parts are original.

I had my pump apart to replace seals then I put it back together and fired it up and the engine ran away (another thread) so I know my valves are GOOD. I took it apart again and saw that the control collar was sliding freely towards the back and not mated to the internal control lever at all. I rectified this, put it all back together properly and got NO fuel out of the delivery valves. Same issue. Solenoid has been eliminated as a possibility. Tried max fuel screw and throttle position in various combinations.

I am puzzled because there is only one way for the lever to go in the control collar. I am 90% sure the control collar is facing the right direction.  Still nothing. Help!

[ORCoaster]

I thought I had trouble with the tab getting aligned into the hole in the collar as well and pulled the top off the pump to see if it was engaged properly as well.  Not the problem.  I did notice that there is a bevel on one side of the collar and a hole for lubrication I suppose.  I tried putting the collar on both ways just in case there was some minor difference in the distance between the hole and either edge of the collar.  I never measured it.  The tear apart pictorial on this site and the exploded views I see in the Bosch literature I have show the bevel to the front of the pump.  But I wasn't sure and built it both ways neither of which made a difference.

I sent the parts back to NC today via UPS.  Should get my return parts in a couple of weeks.  By then my son will have sent me a spare pump he had and I expect to have it working this time next week.  Seems like the more parts I touch on this lil fur ball the more I am spending money on it. 

Tools, bushings and window rebuild, wiring harness for the 99 cent ebay special radio and I think I have dropped a quick 50 on this thing this weekend.   And it is only Sat. night.  This animal is getting all my beer money.  Not a good thing.

Later DAS

[ORCoaster]

What is the difference between a pump stamped 107 A and 107 AP?  My son sent me a spare he had and it looks like the same pump but is the 107 A.  Can anyone tell me if one was an upgrade to the other or just different times of production or what?

Had only enough time this evening to check the condition of the pressure screw and cold start o rings.  He tells me it has been 4 years on the shelf and he ran veg oil through it before he swapped it out with the first pump he had that was leaking.  Once we threw some new o rings on that leaky dog it was good as new so he decided to swap back to it rather than play with adjusting this one for his needs.

Later DAS

[ORCoaster]

Update for you reading pleasure.  Was able to get the spare pump my son sent me installed in the car.  Verified solenoid worked, changed spring from silver colored to red in dynamic advance side, swapped cold start lever as his had no plastic bushings.  Pump worked fine with drill spin test.  All four check valves spitting fluid when I hotwired the solenoid with 12 VDC.

Primed pump and tried to start.  Runs for 20 to 30 seconds then dies.  Check for air in lines, tightened the delivery nuts a bit as some were spraying still.  Working on double checking the placement of the pump timing notch compared to the TDC on the flywheel.  Thought it looked dead on after two rotations of the engine but maybe not.  Was getting dark, ma was calling dinner and I was not real happy.

continue tomorrow.