420 SEL starts briefly, but will not run, Help!

[texastbone]

I recently did a tune up on my car 420 sel 1986, new plugs, distributor cap, rotor, new belts etc. The car has been running great just time for a tune up. It has 160k, best I know. Started the car, and it ran fine for quite some time, 20 minutes, started it several times, no hassle. Took the car for a test drive and about a mile down the round the car just shut off, died. It turns over, seems to fire briefly, 3-8 seconds, something like that, then dies again. It seems to fire, but just won't run. I have triple checked everything I took apart and even replaced with the old cap and rotor. Checked all the vacuum lines, electric sensor stuff for the ELZ, and I tried jumping the fuel pump relay, that doesn't work. It seems like an ignition problem, but the coil is producing spark. I am at a total loss with this, I cannot figure what is wrong. Again, the car fires up, but will not continue to run. The fuel pumps whizzes briefly when I turn the key and turns off, think this is what is supposed to do. I figure its a spark thing, but not sure why it would run fine then just die abrubtly. Any help?? Oh by the way, replaced the fuel filter already, no help.

 

[guydewdney]

more likely the throttle - the cold start mechanism is working - so a secondary air route is given, but the throttle is shut off completely.



dont know how to fix though on your car... try takign off the air filter and looking at the air metering plate?

 

[texastbone]

Thanks Guydewdney...another question

Thanks for the tip, going to have a friend check the throttle control switch with an ohm meter per my Benz manual. The car had been starting and then hesitating, kind of jerky start up before running right. Maybe this switch has been going bad? Is there something else inside the throttle control that could stick or screw up. Thanks

 

[Francois]

Could it be the Over Voltage Protection relay that died?

 

[benzover]

if you pushed the fuel metering plate down to its stop you could have damaged the metering head or knocked it out of adjustment might be worth turning mixture adjustig screw a few times one way and then the other good luck