Timing Belt problem/s

Timing Belt problem/s UPDATE!

Car Info: 1989 Jetta N/A (ME Eng.)
I've been working with a local (to me) owner on this car on multi issues. We/ve covered a lot of ground on this car to bring her "up to speed". Mostly getting the car caught up on some long neglected issues:

Replaced the whole exhaust system
New rear brakes & parking brake cables
New rear brake slave cylinders
New Suspension (front & rear)
Replaced bent inner tie rod (right side)
Brake system flush
Replace all of the door handles
Replaced the shift linkage bushings & rods
Aligned nutral and shift points with the shift alignemt plate

The last issue is where the head ache resides...the Timing Belt (TB).

When I removed the TB cover I found the edge of the TB badly worn & frayed. I removed the old TB and installed a new TB & tensioner.
However...the pump would not move when I tried to adjust the timing.
After much work at last we were able to make the pump move to make a timing adjustment. As soon as we started the engine we both watch the TB "wonder" back & forth as the TB passed from the pump sprocket down to the intermieadate sprocket. By the time the TB travles down to the crank shaft sprocket the TB is partialy off of the crank sprocket about 1/4".
This isn't good. We debated what was the cause ...We desided to replace the intermeadiate shaft sprocket. This improved the situation but did not fully eliminate the TB wonder issue.

After some research on another VW diesel forum it was recommended to replace the pump mount plate. This is the plate that the injection pump is mounted to...not the rear TB cover.
Dieselgeek managed to get us a new mount plate (one of two in all of north America). Again...this new mount plate has not solved the problem.

As a last resort...we decided to remove and inspect the crank shaft sprocket. We did this...to inspect the mating faces between the crank sprocket and the crank shaft. All was clean and in good condition. We replaced the crank sprocket mount bolt (torqued correctly).

This problem still persists...we are at our "witsend"...we've checked and double checked every component in the TB path.

New TB & tensioner...new intermidiate shaft sprocket, new pump mount plate. Every other item that comes into contact with the TB has been inspected...cleaned and double checked.

Does anyone have an idea as to the cause of this problem????

TIA
Herm

Imagine a 1989 Jetta...good shape inside & out...and alot of new components...and we can't drive this little honey

Play in the intermediate shaft bearings? Is there any slop in the pump mounting-to-block interface- is the pump mounting face perpendicular to the block, and could you if necessary adjust it either way to make it so?

DPM said:

Play in the intermediate shaft bearings? Is there any slop in the pump mounting-to-block interface- is the pump mounting face perpendicular to the block, and could you if necessary adjust it either way to make it so?

Click to expand...

I may have forthcoming info on this very issue in the form of a VW TSB.
As soon as I recive the TSB I will provide an up-date.

Herm

Is it possible the belt itself is bad?

-Jason

After several attempts to resolve and correct this problem we have at last had success.

What action finally solved this problem was a bracket adjustment.
The injection pump in mounted to the engine by two (2) seperate brackets. One bracket is located on the front side of the engine directly below and aft of the injection pump. This first bracket has the lower conical nut (below the fuel lines) as part of this bracket. I'll call this bracket #1. With the injection pump removed I loosened all four of the bolts for bracket #1. With bracklet #1 loose I applied finger-tip pressure to tilt this bracket (the bolt hols are slighty over-sized)low on the pump sprocket side and high on the aft mount bolt side. Holding bracket #1 in this position I torqued the 4 mount bolts.

The second pump bracket (or bracket #2) is attached to the engine across the front. Bracket #2 is secured to the engine by six fasteners. This is the same bracket that has the hole to align and lock the pump sprocket at TDC.
Loosen all of the mount blate fasteners. With this plate loose it will let bracket #2 properly set against bracket #1.
Secure all of bracket #2 fasteners starting at the bolt closest to the pump sprocket.

With both brackets secured (and adjusted) reinstall the injection pump and the timing belt. Adjust the injection timing.

Start the engine and check the crank sprocket for timing belt wondering.

I'm damn glad to have solved this problem. The owner was very near to "parting out" a Jetta 1.6 diesel in very good condition.