Caddy 1: Adjust 1.6L TD Fuel Injection Pump

Hey, I have a question for the experienced diesel mechanics. I bought an old Caddy 1.6L TD with the engine code CY. The engine was knocking terribly, smoking black, and starting very poorly. There was also excessive pressure in the cooling system. I then removed the cylinder head and saw a large crack in the area of the swirl chamber. I also noticed that there were marks from all 4 valves on the pistons, and those areas were shiny compared to the other valves, which were completely sooty. The pistons in cylinders 1 and 4 were also not at top dead center. The professionals had set the timing to the wrong mark. I thought, 'I'll put it all back together, and it should run smoothly.'

'I installed a new cylinder head, adjusted the valve timing, and set the fuel injection timing to 0.9 using a timing light, which was very accurate. However, the car wouldn't start. I then rotated the injection pump earlier until the engine started. I then adjusted it further in the early direction until it started knocking, and then slightly back. In that position, the engine runs smoothly, but it's producing bluish-white smoke. When I adjust the pump back and forth, sometimes the smoking gets worse, and sometimes it gets better. I'm not happy with this. Also, the starting isn't working perfectly. I'm not surprised by any of this, because the fuel injection timing isn't correct.'

'My question is, what could be wrong with the fuel injection pump that prevents it from delivering fuel correctly, even when set to the correct injection timing? I have to advance the timing significantly for the engine to start. The valve timing is correct, and I've checked all the connections. I've never had problems with these types of engines before; I've always been able to set them and have them run properly.'

I would be very grateful for a hint.

Did you insert the KSB for adjustment?
Are the hydraulic lifters properly pressurized? Is the air intake clear?
I had blue smoke coming from the engine when it was misaligned, but the 0.9mm clearance at top dead center seems a bit early.
Try to get the engine properly warmed up so that everything can be purged and the ESP has clean fuel. Then, readjust it again while the engine is still warm to the touch.
hg
Herbert.

...and: Was the piston protrusion measured while the engine was disassembled, and was it found to be within acceptable limits?

Best regards, Rainer.

Hello.

- What condition are the nozzles in?
- Have they ever been bled? If so, do they drip afterwards?
- Are they already pretty well ingrained?
- It was at least opened once to check if the correct [items/components] were present.
built-in?

Factory Bosch DN0SD 293.

Replaced by DN0SD 273.
Bosch reference number: 0 434 250 138.
VW Comparison Numbers: 068 130 211 H

These are used according to the Bosch datasheet for all swirl chamber engines.
Polo 1.3D
VW + Audi 1.6D + 1.6TD
VW 1.5D + 1.7D
6-cylinder, 2.4L diesel, 2.4L turbo diesel.
5-cylinder, 2.0D, 2.0TD, 2.4D.
VW + Audi 1.9D + 1.9TD

Poor injectors also require an earlier injection timing in swirl chamber engines and severely worsen the starting behavior. Additionally, the symptoms you are experiencing, such as blue-white smoke and erratic running, can also be caused by faulty injectors.

Also, here's the translation:

"Also, occasionally check the foot valves on the high-pressure side of the pump for a broken spring."

Regards, Mpire.

dieselschrauber wrote:

...and: Was the piston protrusion measured while the engine was disassembled, and was it found to be within acceptable limits? Best regards, Rainer

Hello!

Based on my experience, I have similar concerns as Rainer. The engines of the first generation of diesel vehicles don't handle valve-piston collisions very well.
I don't want to jump to conclusions, and it's possible that each individual case could turn out differently, but before spending hundreds of euros on things like fuel pumps, it would make sense to perhaps measure the compression first and then think things through carefully.

It's been over 25 years now, but with my first diesel Golf, the timing belt also broke due to excessive caution and lack of knowledge. I replaced the valves and continued driving. After a while, problems started to appear, such as difficulty starting and, especially, an uneven engine running/vibrations. I didn't investigate the cause; I got another engine for free and installed it.
But I'm assuming that something happened to the crankshaft mechanism. So, maybe the crankshaft is bent, the connecting rod is crooked, or something like that.