[jkaiser]

Car: 02 Jetta automatic

Strike 1 - Idler frozen towed to shop replaced ran fine 200 miles

Strike 2 - Tensioner spring tab broke belt got loose but I cuaght it in time
Back on the tow truck. Replace belt with new continental kit. Ran fine
170 miles.

Strike 3 - Car died at 70mph, this time I was not lucky. The idler bolt broke
the belt jumped. I towed the vehicle off the expressway and had it towed
to the shop again. This time new valves, lifters belt and oem bolt.

Currently the car will not rev. When warm it will rev in park but not while
in gear. Me and the mechanic are at a loss. We ruled out fuel obstructions
in the tank and filter. Car starts right up and there are no known vacuum leaks.
Intake and exhaust are clean and clear. No codes being thrown.

Please help, got a lot of money in parts and labor and still no car. This is
my second attempt at this post so if you see a dup....sorry.

Thanks in advance.

 

[chittychittybangbang]

How the heck did the idler bolt broke? Who did the timing belt? Did they use a new bolt or reuse the old one? Did they use a torque wrench? The large idle bolt is a single use only torque to yield stretch bolt. The other idler is on a stud.

Automatic or manual transmission? It could be a number of things, take a look at this FAQ article: http://www.myturbodiesel.com/1000q/multi/low-power-fix-TDI.htm and see what you've done and what it could still be.

 

[jkaiser]

The car is an automatic. They reused the old bolt which broke. I will re-read the document. The car ran perfect before the final failure.

 

[Seatman]

welcometomyturbodies

Has the intake and egr ever been cleaned? They can clog up pretty bad and can kill the power too. It might be worth popping off the intake pipe to the inlet manifold and having a look.

 

[jkaiser]

I read the low power documents again and here are my thoughts. Being that the only things that have been alterered are the head (new valves and liftters) and the timing belt. I am recommending to the mechanic to verify all timing and then do a compression test. The car ran perfect prior. If this doesn't work I am going to have to take the car to a TDI expert. Anyone know of someone in SE Michigan?

 

[jkaiser]

Went to the shop today compression is great on all cylinders, timing marks are all good. Everything is good and clean. All I can think is I am starting to think I have a bad peddle switch not sending the correct signal to the ecu. No codes though. They also replaced the starter if thats another clue. Are the peddle specs out here anywhere?
thanks in advance

 

[jkaiser]

I tested the pedal and this is what I found. I have nothing to compare but they seem at least logical/reasonable.

6 pin connector:
All readings are from idle(pedal at rest) to full(pushed to floor)
1+6 open until 3/4 or so then closes( switch)
5+6 cosed then open after initial pedal push (switch)
2+3 Always closed
2+4 1.7 Kohms to .9 Kohms
3+4 .9 Kohms to 1.7 Kohms

I am thinking I may have a problem with the connector or harness to the pump if these reading are good.

Question:
How can I test voltage to the pump?
What triggers the pump to add more fuel?

 

[chittychittybangbang]

Don't know the pedal specs but if it's out of spec it will throw a code and send you car into a high idle. It has 2 sensors built in there. The ECU gets signals from the various sensors and inputs and tells the pump to add more fuel. All electronically controlled. I don't know if there's something about the auto which would cause it to rev fine in park but not otherwise. You say it will not rev at all? Neutral? Only when warm?

In a diesel, engine rpm is controlled by how much fuel you are getting. How much fuel you are getting comes from IP. IP control comes from ECU. It's pretty rare in general to have ECU failure unless it gets wet or something like that but I have heard of a few bad ECU on mk4 TDI.

 

[jkaiser]

I am starting to think it is an electrical problem going to the pump. Here are some assumptions. Pump gets an idle signal to initiate fuel to run at all times if ignition is on. This circuit is good. When you accellerate an increase of voltage or resistance is sent on the same or second circuit. This second signal is my problem. I really think I have a bad/weak connection somewhere on this second signal. I think my drive/nuetral thing may be a fluke based on loading the motor and moving/wiggling a bad connection. Hence the questions below.

Question:
What signal can I measure/investagate at the pump?

Very sorry to be such a pest and many thanks to all.

Before I wrap up this job, what other bolts do I need to replace when doing a timing belt???????

 

[chittychittybangbang]

Motor mount bolts, large idler pulley bolt, harmonic balancer pulley bolts (will probably strip)

There are some notes about the belt here: http://www.myturbodiesel.com/1000q/a4/ALH-engine-timing-belt-change-VW-Jetta-TDI-1.htm

It could be a wiring harness problem like a rubbing wire that has broken or an internal fault in the pump, they often throw codes.

 

[Growler]

you need to get the car to martin bergel in fowlerville, MI.

one of the best guys in the area... worth the Tow.
http://www.martinbergelllc.com/

best of luck.