VW Mechanical fuel pump Q

[conan1977]

Hello and good evening all. I am posting a question outside the bounds of us Jeep peeps :bowdown: Anyway, not only do I have my 92 Comanche, and 99 Cherokee sport that I give love to (no real love making...I hope you get my drift), I also have a 71 VW Bus Bayside (1600 cc) that I am fond of. I am not posting this question on any VW blogs or other sites (I will not mention, because I am a member), Lets just say they are pretty much arrogant "Richards"--sneaky way to say the short version. Every time I have a question they snooty poot around.

Finally, my question is that my mechanical fuel pump seems to be getting fuel via gravity fed, the fuel screen is clean, and no blockage in the line. Now, when it is running at idle it runs fairly well but there is a small amount of fuel in my inline fuel filter (sometimes it goes completely empty and gurgles for fuel...air bubbles). When putting a load on the engine, there is barely fuel available. I took my fuel cap off (checking for vapor lock), still had these issues. Other than this small issue of fuel starvation, all systems are a go. Is it time to get another fuel pump or should I rebuild the pump? A new pump is minimal (around $70). I am open for all suggestions and I apologize for this post if it ticks anyone off, but you guys have been great here and that is why I posted this question. :cheers:

 

Conan

[jpdocdave]

:fs1: gosh, who let this guy in? what do you think this is, vw forum, man what a jerk. what a stupid question to, lets bash him. :mad:

 

 

:clapping:

 

just so you could feel at home :yes:

 

anyway, i'd take that filter off and make sure its not too restrictive, they have different micron ratings, and one off the shelf may have been too fine for this precision machine. :D

 

after that if everything is clean, and its a mechanical pump i'd say replace it. not sure how well you'd do rebuilding, they are simple but annoying. rebuilding yours would be cheap, but if you do something wrong, you will be scratching your head thinking, is it a different problem, or is it still the pump :hmm:

[Sir Sam]

Hello and good evening all. I am posting a question outside the bounds of us Jeep peeps :bowdown: Anyway, not only do I have my 92 Comanche, and 99 Cherokee sport that I give love to (no real love making...I hope you get my drift), I also have a 71 VW Bus Bayside (1600 cc) that I am fond of. I am not posting this question on any VW blogs or other sites (I will not mention, because I am a member), Lets just say they are pretty much arrogant "Richards"--sneaky way to say the short version. Every time I have a question they snooty poot around.

Finally, my question is that my mechanical fuel pump seems to be getting fuel via gravity fed, the fuel screen is clean, and no blockage in the line. Now, when it is running at idle it runs fairly well but there is a small amount of fuel in my inline fuel filter (sometimes it goes completely empty and gurgles for fuel...air bubbles). When putting a load on the engine, there is barely fuel available. I took my fuel cap off (checking for vapor lock), still had these issues. Other than this small issue of fuel starvation, all systems are a go. Is it time to get another fuel pump or should I rebuild the pump? A new pump is minimal (around $70). I am open for all suggestions and I apologize for this post if it ticks anyone off, but you guys have been great here and that is why I posted this question. :cheers:

 

Conan

 

 

Have you posted on, www.thesamba.com ?

[dasbulliwagen]

Are you having running issues, or are you just worried about the amount of fuel in the filter? And are fuel pumps $70 now? I guess its been a while since I bought any. If you are getting fuel starvation at higher RPMs, then I would say maybe the diaphragms are getting old and should be replaced or the whole pump replaced. Just be sure to get the right model as there are a few different ones depending on if you have an alternator or not, or the plastic isolator or not. I'm sure you know that part already if youve been into VWs long enough. Or you can buy a blockoff plate and wire in a low pressure inline electric pump available at any VW aftermarket supplier. Good luck!

 

 

wanna buy a 68 Bug?

[Randy in Maine]

Nothing wrong with the mechanical fuel pump on a 71 baywindow, but keep in mind that the pushrod is different for a generator equipped vs an alternator equipped bus by about 1/4". If you recently went from a generator to an alternator, that could be the promblem. A fuel pressure gauge will tell you what yours is putting out.

 

A new pump is only about $25 from here.... http://www.busdepot.com/view.jsp?model= ... odgroup=-1

 

Also make sure that your are using a metal fuel filter located by the tank and not once of those cheap plastic ones betweent he pump and the carb.

 

Make sure the fuel sock in the fuel tank is not all munged up and is free flowing. Poke a hole in it if needed. When the pumps die, they usually do it when your are demanding more fuel at high RPMs. If you decide to replace it with an electric one, buy a 3.5 psi rotary fuel pump from CB (not a "facet type" pump) and run it off a relay, not off the coil.

 

Just my 2 cents.

[dasbulliwagen]

:agree:

[conan1977]

Thanks for your input. I appreciate the help. Also, thanks for not kicking me in the Johnson over posting this question in the Comanche club. Again, thanks a ton.

 

Conan :clapping: :cheers:

[Randy in Maine]

One more thing.....if you end up with a new Brosal pump, sometimes the "in" and "out" lines are reversed.

 

Hook up the one you think it is and confirm that you are really pumping fuel.

 

It took me way to long to figure that out once.

[Cheech]

I just went through replacing a mechanical pump myself, but it was on a tractor. It wasn't the injection pump, but it was the small lift pump that runs off the camshaft and pulls the fuel up to the main injection pump. Probably very similar situation to the VW. Everything ran fine, but it leaked really, really bad. I priced replacing the diaphrams, but a new pump was only about $60 so i went in that direction. For the price you are quoting its not worth trying to clean it all up and hope that it will start to pump again. I would just go new. I have also heard of the pumps on the VW diesels starting to let air into the system and the fuel then drains back to the tank leading to lots of cranking to try and prime the system again.