I bought the lost spring from the local Bosch dealer and re=sealed all 6 delivery valves. Started the engine before installing the intake and resonance manifold. Found no leaks. Put everything back together and started the engine and while doing a test run, I noticed a slight miss. How can I find which cylinder is the problem? Not having spark plugs I don't know how to check. Any pointers?
That seems to be a common issue when doing the delivery valve seals. I ended up doing mine twice. I had read a number of posts on different forums, and some of the posters indicated it was not necessary to change the crush washers when doing the job, so I only replaced the rubber O rings. When I first started the car from cold, the engine ran just as smooth as it did before I did the job. After about a minute, to a minute and a half after starting from cold, I noticed a miss, which was only present at idle, or when going about 15mph and taking your foot off the throttle. There was no problem with smoke, or power, only at idle. After doing further research, a number of posters who had the same issue indicated that the miss would go away after driving the car for a while, and some used Diesel Purge to help. After driving the car for about 300 miles, with no improvement, I decided to do the delivery valves again, only this time replacing both the crush washers and rubber o rings. I torqued all the valves to 32 n/m, and after starting the engine, the miss was gone, and the engine was a quiet as it was before I started the repair. When doing the job the first time, the reason the engine was so quiet starting from cold for the first minute or 90 seconds was the fact that the afterglow process was activated. Once that was finished, the miss was immediately present. It is my thought, that by not doing the crush washer replacement the first time, the delivery valves were allowing too much fuel into the injectors, and as long as the glow plugs were activated, there was no problem. Once the afterglow process ended, that extra fuel created the miss. Good luck with your vehicle.