606 Pop Pressures

[MB140300SD]

While I had everything apart to do delivery valves I decided to go ahead and install the Bosio nozzle I bought for it. I do not have any shims so I was just gong to swap nozzles and move on. I’m currently on my first nozzle and have an issue. I tested the nozzle and it is pissing fuel and sort of leaks after it’s done spraying, so needs to be replaced. I took the injector apart, soaked the bits in parts cleaner for a while then installed the new nozzle. Original nozzle popped right at about 135 bar where it should. With all the parts the same the Bosio nozzle if I am reading my tester correct it only appears to be popping at 90-100 bar, which is way too low, correct? I do not think I can run them this low. I took apart a 603 style injector and the shims in it are too big to fit in the narrow 606 body. I need to add shims to increase pressure, correct? If this is not going to work I may have to abandon the project until I can get some shims for 606 injectors.

So I went ahead and installed the injectors just to see what would happen. Car started and idled smooth, but when you revved it up, it smoked like a freight train. Probably dumping too much fuel. I can't figure out why the Bosio nozzles popped so much lower than the original nozzles with all the same hardware. I currently have the original injectors soaking in carb parts cleaner and am going to reinstall them in the injectors in the morning.

[dlssmith]

I would probably shim it slightly and then test again. It is possible the spring is at fault, but probably not. Also be sure the nozzle is clear - even a new one can be blocked. And watch the fumes - def don't breathe them in...

[MB140300SD]

Well the job is done. I reinstalled the original nozzles back in the injectors and tested them. All popped 135 but 1 had sort of a after stream pissing fuel after it fired. I took it back apart, dropped the nozzle back in the cleaner again and sloshed it around, then when I put it back together it seemed much better.

Problem I was trying to cure was idle seems loud it this car sort of rattled like a 617 and if you let it idle for a while it would start smoking. The delivery valves were also leaking and probably letting air in as it would sometimes act like it was starving for fuel when cold. I can’t really tell if all this made it idle any more quiet or not but it does not seem like it’s smoking like it was when you let it set and idle. I would still like to go ahead and replace the nozzles at some point but I need to locate shims first

[onstottc]

I found shims here: shop.dtp-motorteile.de