Author Topic: 2001 jettA IP SUCKING AIR  (Read 3390 times)

March 30, 2015, 09:46:36 pm


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« on: March 30, 2015, 09:46:36 pm »
i never had so much trouble with a diesel. my old 97 tdi passat would start without bleeding.

anyway i have a 2001 ALH. the clear fuel feed line goes from solid to empty every few seconds. engine dies down when it starves.  The IP head sometimes would drip. I decided that must be the problem. So i changed the head seal with the large green oring.  I don't see any dripping. I got IP primed by using an electric pump. to my amazement same problem Clear line goes from solid to empty when running.  So ran a line straight from filter to bottle of diesel. It' s still doing the same thing.

I tried to prime it by sucking on the return hose . It is very hard to pull fuel thru the return line. I tried it on another tdi and i could suck fuel thru the return line with no problem. Is there a check valve in the steel  return line coming off the IP????

could it be a vane in the rotor is broken??? i getting aggravated!!!

« Last Edit: March 30, 2015, 09:49:14 pm by 91mk2 »

Reply #1March 30, 2015, 11:32:34 pm


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Re: 2001 jettA IP SUCKING AIR
« Reply #1 on: March 30, 2015, 11:32:34 pm »
Check the plastic valve thing on the fuel filter and the o-ring under it as well. Or try bypassing the filter (make sure it's clean fuel) and see if you still have the issue.

Reply #2April 01, 2015, 10:34:24 pm


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Re: 2001 jettA IP SUCKING AIR
« Reply #2 on: April 01, 2015, 10:34:24 pm »
If you want to KNOW if it is the IP or not, pull a vacuum on the return port with the input fitting plugged with a finger. If it is NOT leaking air it will hold a good 25" of hg. If not you have a leak it won't hold a vacuum, so jerk the pump for a reseal. You can fart around for weeks trying second order stuff and still not KNOW if it is sucking air. FWIW these leaks are not uncommon, but often quite hard to find since the often don't drip fuel.

Plugging the other port(s) with a clean finger eliminates leaking hoses, clamps, and hose pinchers. If air is leaking by your finger you can feel it.

A Mighty Vac works very well for this.
« Last Edit: April 01, 2015, 10:36:00 pm by Toby »

Reply #3April 03, 2015, 06:30:49 am


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Re: 2001 jettA IP SUCKING AIR
« Reply #3 on: April 03, 2015, 06:30:49 am »
Good luck with this as I rapidly lose the will to live sorting out these air leaks. I suspect many of the plastic thermo valves are cracked from new. The mk1 type filter worked well, but you might get hassles with fuel gelling in very cold weather. ;)