Thanks to naj, glennard, Mr. Alexander for your valuable information. I will check the websites mentioned.
A little additional info on Amy's sl. It has the origional distributor. Adjusting the fuel mixture has a small effect on the problem but does NOT clear it up. Ign. timing has little or no effect. Glennard's suggestions have all been checked and are within factory specs. Having been trained by MB on this system, I am aware how important linkage adjustment is and will check Joe's linkage tour and other website mentioned by naj. I would like to set linkage properly and then recheck my previous work, including all suggestions posted below, and check exhaust emissions to verify results, i.e. rich or lean condition. Currently, I feel that this is a lean backfire. Fuel pump pressure and delivery rate are within specs. Fuel filter has been replaced. Fuel injectors cleaned and inj pump rebuilt by Bosch rep in New York. Injector opening presures within specs. Fuel lines have been blow clear from pump to injectors and pump to tank. Tank filter checked for debris and is clear. Tank is clean. Tank vent is in working condition. All rubber fuel lines are new and all banjo bolts are clean. I have been looking for the factory degree tools for linkage setting. In their absence, I will use Joe's tour. After linkage is properly set, all other ign., tune up, and engine condition specs will be rechecked for possible errors or oversights on my part. Any further ideas will be happily received, as thirty five years in the profession have proved that I do not have all the answers and I have learned to enjoy the taste of crow, no matter how it is prepared!
On another subject, Amy has a 1958 220S Cab. with a Hydrac. I am very familiar with the Hydrac having repaired many over the years. Thanks to Amy I have all factory Hydrac literature. I believe that it is causing a vacuum leak, making it necessary to run the engine with the choke slightly out to prevent stalling. This tactic, however, ruins the smooth operation of the Hydrac. If I plug the vacuum tap at the manifold, the engine runs fine. The vacuum diaghram, brake booster, and vacuum reservoir all hold vacuum overnight. All vacuum lines have been replaced with the proper wire reinforced hose supplied by MB with new hose clamps, all tight. It looks like the Hydrac vac. control valve is leaking to the atmosphere and needs rebuilding. I needs parts or a new or used (any condition) valve. MB has no spares for this valve. Also, I want to rebuilt Amy's spare Hydrac fluid coupling and need bearings and seals, and one way clutch parts.
I also need suggestions about adjusting the shift linkage box at the base of the steering column unit. After installing new shafts, bearing and seals, and before installation this linkage assembly functioned smoothly. After installation all gears engage smoothly except 2nd which takes extra effort. 2nd must be pulled in with some force, whereas the other gears glide smoothly into engagement. I followed factory adjustment procedures and rechecked adjustment twice. Gearbox has all new bearings, gears and synchros are in good condition. What am I doing wrong?[/u] This linkage is the same as a standard manual transmission. Any info or suggestions more than welcome!
Thanks, Ted Rosenlund, 3706 Gap Newport Pike, West Grove, Pa 19390. Actual location is on Rt 41, 1/4 mile north of the village of Chatham, Pa.