W113 Pagoda SL Group > W11x chassis cars
cold mixture adjustment for 2 plunger 220SE
wwheeler:
Does anybody know how to adjust the cold mixture for 220SE (2) plunger pump? I am familiar with the warm mixture adjustment.
Thank you,
Wallace
Benz Dr.:
I did one last fall and it wasn't easy. Before you start you need to check all of your injectors. Breaking pressure should be within 7 PSI for the working group of three injectors. Try to match them so they all break at about the same pressure. You can have one group higher than the other as long as the three injectors in each group are a matched set. If even one injector is weak you won't ever get a decent idle mixture and the engine will always sputter and miss.
After you get your injectors sorted out you should make sure that your distributor blocks are all flowing evenly. I always tested them with the lines and injectors attached so I could see what the final output was. Again, any problems at this point will need to be sorted out. Good used injectors are getting very hard to find - and no, I don't have any. :(
The slide valve is similar to our 113 cars but it may have a small screw on the top of it which can be adjusted. The one I did last fall didn't have a screw so we very carefully ground a small amount off the central pin until the air valve was completely shut off. I think we may have removed the air jet to give it a bit leaner idle mixture. Took the better part of a day before we had it right.
All I can say is that this is a very difficult engine to tune. The car we did never really ran right until we did all of this stuff and then it was like a totally different car. No more stalling, great idle hot or cold, and it started every time.
wwheeler:
Thanks Dan.
I have checked the injectors and blocks with my injector tester from India. I am familiar with the six plunger pump and was hoping the adjustment was as easy. I guess not. :( I have the service manual on the pump and it talks about the air slide valve as you mention. The engine has been rebuilt and is currently on a test stand to work out the bugs before install. Warm idle is great, just a bit too much fuel during cold running. I do need to see at what temperature the air valve shuts off though.
Thanks for the help and sounds like fun!
Happy New Year, Wallace
PeterPortugal:
Hi Wallace,
Can you provide any details of your "Indian" test equipment? I will need to do this job.
Regards
Peter
wwheeler:
http://www.fiptestbenches.com/injector-nozzle-testers.html
I have the NTG 400. Yes, it is a diesel scale gauge, but it is easy to see the 200PSI or so mark where the injectors are supposed to open up. The cracking pressure is just one reason to check them. The spray pattern at the cracking pressure and leakage below are the other reasons. You can really tell a difference in the spray pattern with some injectors after a cleaning.
I went ahead and bought two more gauges. One that is a max 1000 psi for the injectors and one to 60 PSI that check the cold start valve. I believe the original threads are BSP (British Standard pipe) and so to use tapered pipe gauges, it requires an adapter. I hope that helps.
Navigation
[0] Message Index
[#] Next page
Go to full version