81 380SL odd running problem
 

All, I'm having a problem with an 1981 Mercedes Benz 380SL It seems to run relatively smoothly at idle (with a little irratic-ness) but on the highway, once you get it to speeds, it begins to hesitate as if it's not getting enough fuel.

I'm thinking there is a fuel blockage issue but the pump appears to be new.

When I put a c/o meter on, a 10 degree turn anti clockwise will result in moving the c/o mixture from 4% C/O to 0.2% C/O.

I purchased this car for a buddy who has to drive it to Wisconsin in a couple of days.

Any thoughts would be appreciated.

Sounds like the fuel filter. Had the same problem with an old VW rabbit years ago..

This can also be ignition advance being too retarded. You then have the feeling you are pulling a trailer, with the car being "pushed" and "retained". If your advance is OK at idle, check it at 3000 and 4500 rpm, and see if it is correct. Also check for vacuum leaks in the advance system.

Gang

Thanks for your help. Today we did a fuel flow test and could fill a 1 liter bottle with gas in about 18 seconds so it's all good. We checked the timing at 1500rmp and at 3000rpm and it was within spec.

The coil was not a Bosch coil (instead one made in Mexico). As we had only noticed this problem while the engine was hot, we replaced the coil with one that I had lying which was taking from one of my SLC 5.0's and then took it for a drive.

Problem solved. Thanks for your help.