Engine Specific Info and Questions > IDI Engine

injection pump breakage

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Artsi:
I had mine 1.6TD die on me when cruising on a highway. It acted like a gasser engine loosing ignition totally.
It cranked fine but did not come back to life.

After some initial inspection work, it seems like that fork type mechanical coupling inside pump most likely has given in and broken up into pieces. Pump gave out funny unnerving attenuated ticks as I hand cranked the engine very slowly.

I did fool around with enriching the fuel delivery as I changed the belt, thus mechanics inside pump maintaining control collar in closed position longer than usual. I managed to clock only less than 20 miles with new settings & belt, when it died on me.
I wonder if that prolonged injection window drove the pump to attempt injecting more fuel than injectors flow, thus causing rather terminal stresses upon fork type coupling.
It did not smoke when I drove real nice, but smoked like a freight train when I shoved the go pedal.

How common breakage is this afterall?

-A.

chrissev:
what procedure did you use to reset the timing when you put on the new belt?

Artsi:
I parked engine at no:1 cyl TDC, used specific locking bar to hold camshaft at TDC. I swapped the belt, wrapped a new one around all pulleys. I undid camshaft sprocket, left it in place so belt was able to rotate it if needed. I had a pin locking the pump sprocket through the face of the sprocket into pump housing, thus holding it at no:1 cyl feeding point. Tightened everything when engine at no:1 cyl TDC. Checked pump plunger movement to be 1,1mm at TDC. (I know it should have been 1,00mm's ,but this was an experiment since many have reported good results with 1,1mm timing.) I re-checked timing maybe 2 to 3 times over, handcranking the engine between checks.
I used dial gauge with magnetic base for pump timing. In all checks it yelded same result.

This is how I did it in my 1.9TDI engine some months back. Absolutely no probs with it at all. Been clocking many kilometers after that manouvre, maybe 10 000 km's.

Artsi:
Pump disassembled. Plunger seized, shaft broken in 2 places, on both sides of the control collar. Looks nasty.

No wonder the car jerked, a bit like very sudden tap on the brakes, and it was over in a fraction of a second. It has to take a lot of torque to twist that hardened 9mm steel shaft until it gives in.

What still puzzles me, is whatta heck caused the plunger to seize in the 1st place?

QuickTD:

--- Quote ---What still puzzles me, is whatta heck caused the plunger to seize in the 1st place?
--- End quote ---


Dirt in any form will seize the plunger, as will running low on fuel and having the pump suck air. Cold water poured over the pump head will do it as well, so avoid washing a running diesel engine. These parts are fitted pretty closely, to millionths of an inch. It doesn't take much to get them to seize.

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