

| Subject: | Re: Debugging air leaks in a Diesel |
| From: | Gary Bawden |
| Date: | Mon, 13 Jun 2011 21:28:21 -0700 |
Hi Poppie, I ran a Jetta diesel with the same minor air leak at the shaft for two years like that, i.e., with an 'el cheapo' fuel pump from the local FLAPS, and a button mounted down under the dash. Very simple - - hold button down for about five seconds to purge air, hold button for glow plugs for a few seconds (I don't believe in replacing expensive glow plug circuits once they quit working), then start. The only caveat I can think of is to make sure the pump flows freely when it's not pumping - - try blowing through the inlet tube to check. If it's not a free-flow type you'll just have to let the pump run continuously while the engine is running. The pump on eBay looks similar to what I used. Gary le in the fuel return line as I wrote before. However putting the can a foo= > t or two above the injection pump, and thus creating a small over pressure > = > into the pump, then the bubbles go away. Instead a drop or two (very > little= > ) Diesel leaked out around the input shaft. I saw no other > leaks.=0A=0AThis= > small air leak does not seem to affect driveability. It just takes a lot > o= > f cranking to start it. Bad for starter and pump! Doing the seal would be > e= > asy when time for the timing belt and tensioner change. Until then I'm > temp= > ted to put in an in-line fuel pump at the tank with a switch so I can > prime= > the pump before starting.=0A=0AMartin=0A=0A--- On Mon, 6/13/11, Poppie > Jag= > ersand <poppie.jagersand@yahoo.ca> wrote:=0A=0A> From: Poppie Jagersand > <po= > ppie.jagersand@yahoo.ca>=0A> Received: Monday, June 13, 2011, 1:18 AM=0A> > U= > pdate on the slow progress on=0A> getting the Westy road ready. Our > vacatio= > n got delayed a=0A> month so I have not been working on it at the speed I > s= > hould=0A> have. Put in another afternoon in the debugging this=0A> Sunday.= > =0A> =0A> Looks like the unfortunate news is that the injection pump=0A> > it= > self has a very small air leak. I have replaced all the=0A> rubber hoses > fo= > r the injector return lines (the usual=0A> suspects). Then I disconnected > t= > he fuel; in and return lines=0A> on the pump and connected two new hoses > th= > at I ran directly=0A> from a jerry can of Diesel fuel. =0A> =0A> When > start= > ing the pump would first purge the air, so pushed=0A> big air bubbles > throu= > gh the return line. However, even after=0A> some minutes of running, small > = > air bubbles would remain. I'm=0A> not sure how long it takes for the air > to= > be completely=0A> purged, but it looked to me as if there was a > continuing= > and=0A> not diminishing amount of small bubbles.=0A> =0A> So I'm running > o= > ut of "easy" things to change. I guess I=0A> can change the copper washers > = > on the input and output fuel=0A> fittings on the pump. If that doesn't > help= > what else can I=0A> try short of removing the pump and replacing > seals?=0A= > > =0A> I'm thinking since the bubbles continue when running, the=0A> leak > s= > hould before the vane transfer pump. I'm not sure what=0A> shafts seals > sho= > uld be most suspect, but the input shaft=0A> might be one.=A0=A0=A0=0A> > =0A= > > Let me know what you think and if there is anything else I=0A> should > tes= > t.=0A> =0A> I tried Gnarlie's oil squirting trick on the inlet=0A> > fittings= > . Wasn't sure how to get motor oil to the input seal=0A> without risking > sp= > lattering one the timing belt, so didn't=0A> do that. (Bad idea since > backs= > ide of timing belt drives the=0A> intermediate shaft, and oil on the belt > c= > an make it slip.=0A> b.t.d.t. on my previous B2 Passat TD)=0A> =0A> I > might= > also try adding a low pressure electric pump at the=0A> fuel tank as > sever= > al forum members suggested. What do you=0A> think about this ebay > pump?=0A>= > > http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=3D220797730011&ssPageNam= > e=3DSTRK:MEWAX:IT=0A> > *********************************************** >
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