a test for diesel guru's

[CRSMP5]

while out at athens euroworks.. was doing some maintence on a td jetta... we solved a really unique issue..

owner runs bio diesel thru it alot.. almost a year ago had a starvation type of issue so threw in a inline filter vs a normal diesel filter.. so was time to install a fresh proper diesel filter...

installed it.. all of a sudden would in no way prime the fuel system.. put back in canester.. still no prime..

add in a pump to feed the fuel into it... again no go...

pull pick up from tank... no issue there...

SO WHY?? what happened? ill let you all guess at the reason for a few days.. it is impressive... and unexpected... but really unique that has a simple test...

[CRSMP5]

22 views... not a single guess... is it that hard? this could be your diesel...

[fatmobile]

A chunk of something clogged the banjo barb?
 Oh wait,.. Mk1 or MK2 Jetta TD?

[ORCoaster]

Ok, I'll venture a guess with some assumptions of course.  

Assuming that he was mixing Bio Diesel and regular diesel in the same tank:  Bio D has a tendency to dislodge junk in the tank.  So even though his fuel was pulling through the filter and not restricted at the tank I am going for a goober lodged at the the filter inlet.  When you pulled the old in line filter off the plug moved into the first part of the filter and sealed the inlet solid.  

The simple test is to remove the banjo at the inlet and blow air through the filter and out the banjo that attaches to the filter itself.  Thus ensuring that the flow line is open from filter to IP.

Not even close you say?  OK, someone else think up something better than mine.


While I was making up a story Fatmobile beat me to a guess.  Dang it.

[bajacalal]

A french fry in the fuel line.

[smutts]

Air leak between tank and pump. Death of that stupid plastic thermostat. Filter maker forgot the seal for the water drain. Cracked plastic fuel pipe. Rusted pipe clip hidden between tank and car body. Etc.

Someone put the stupid plastic thermostat back to front! Wrong I know, but it is all fun.

[CRSMP5]

mk2 td.. nope fuel flows no issue to pump... it only took 3 grown men 2 hours... i was somehow the supervisor too.. LOL.. suggest something and watch others work.. LOL.. how many diesel mech does it take to?... LOL..

flow to pump.. lift pump pushing fuel... lift pump creates so much pressure it actually stops working and springs a leak... in all posts answere is there... but not zeroed in on...

it something you over look as a how can it... car drove in just fine, nothing more then filter change, issue to fix..

yep... idea is fun time with a little educumation

[dieselweasel]

restricted pump return fitting

[CRSMP5]

plugged solid... when i cracked it loose the air pressure escaped... so if you ever have a issue priming your pump... crack that baby loose.. if its like a good ol balloon lettin air escape look at it.. 

[ORCoaster]

Well that was fun and educationamal.

[R.O.R-2.0]

Well that was fun and educationamal.

edumacational**