Date: Sat, 14 Dec 2002 18:14:48 -0700
Reply-To: Martin Jagersand <jag@CS.UALBERTA.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Martin Jagersand <jag@CS.UALBERTA.CA>
Subject: DIesel FI, Was: Question about TDI Jetta Problem
Just as you I have no experience with this particular model, but
I do beleive it has the same Bosch VE pump as all other North american TDI.
This pump is mechanically almost identical to traditional style
non-computer controlled pumps. Only difference is that there are now
electronic controls instead of mechanical governors, timing advance
aneroids etc. See my rochester www site (www.cs.rochester.edu/u/jag/vw).
Hence, many problems can be solved by good old trouble shooting.
Your cousin's problem might be: (In sensible diagnosis order:)
a. Air in fuel line and return system (yes: also return system: I once spent
hours diagnosing just the same problem on a Passat, until I found a pin
hole leak in the fuel line near the tank.) The leak was small enough to
let the car start and idle, yet when pulling more fuel it got mostly
air.
Check for air bubbles in a clear segment of hose.
b. After checking and being 100% confident it's not the easy to fix
fuel line problem it's time to suspect the pump. Here it's time
to differentiate between the complete "fly by wire" style pumps
and those that thankfully still have mechanical accelerator
control lever (ie the thing that is *not* a throttle on a Diesel, but
performs the same function... ;-). The good news with the latter style
of pump is that the engine should run (albeit roughly) even if the
electronics are flaky. There are two more things in the way before
getting fuel to the cylinders.
1/ Fuel stop valve (named magnet valve on:
http://www.cs.rochester.edu/u/jag/vw/engine/fi/injpump.html)
Should have 12 V. If suspected defective remove.
The adventerous may try to carefully take out the small plunger
and spring, reassemble then attempt to start enging. Note: now it won't
of course stop with the key (just like real Diesels...). You
would have to stall it or starve it fo fuel.
2/ Vane pump. (called "feed pump" in my illustration) On a relatively
small number of 1.9l engines the vane pump has for some strange
reason failed at <100 000 miles. You can check by leaving the
above mentioned stop solenoid out completely. When cranking fuel
should come out of the hole. If this is the problem VW should really
replace it free, but afaik I have heard they sometimes try to make the
customer pay.
There are some other potential problems, but they ought to not have
given the defective fuel pump diagnosis on the computer.
Let us know how it goes.
Best,
MArtin (And '82 1.9l TD Vanagon)
PS Someone emailed me that you had a new coolant hoses, tanks and mounts
to set up an '82 as a late model (Europeean or South African?).
Do you have more info on that?
Date: Thu, 12 Dec 2002 12:39:51 -0500
Reply-To: Kenneth Wilford <kenwilfy@COMCAST.NET>
My cousin Brian bought a 2001 Jetta TDI. 50k miles later his car loses
power and dies while driving down the road. After having it towed to a VW
service shop they are telling him he needs a new fuel pump. Pricing them
they are around $1300. What I am wondering is this:
I have heard that the new TDI engine has a timing chain instead of a belt.
If this is true then does the belt just drive the fuel pump? If so then
could he merely have a broken belt for the fuel pump and the shop is really
just yanking his chain? He spoke to the VW dealer and they are saying that
the fuel pump does NOT fall under the power train warranty (hard for me to
believe).
Anyone with input or experience with a similar problem would be appreciated.
I don't have any experience with the new TDI cars since they are so new that
there isn't really much in the aftermarket for them yet, and also since most
of them have not yet had any major problems because they are only a couple
of years old.
