initial air/fuel adjustment hex position - PeachParts Mercedes-Benz Forum

deportes · #1 03-10-2007, 07:53 PM

1983 380 sl. What position is the best initial to start from, I replaced my fuel distributor with a spare but it won't run it starts and dies if at all.
I sthere a way to determine electronically where itshoeuld be started from and then adjust. Or mechanically.

cool · #2 03-10-2007, 09:04 PM

make sure first that all the other part like electrical and fuek system are working right, its an elimination game, may I ask why you need to replace the fuel distributor to best understand your situation (facts).

cool · #3 03-10-2007, 10:18 PM

you'd also need a co guage to get the right adjustment for your CO

deportes · #4 03-10-2007, 10:23 PM

I stripped one of the distributor lines so I replaced with one from a wrecker, the problem is the one I removed is gone from my garage. The one I installed, hex screw was backed out all the way, as lean as possible i think. Now I can start my car and don't know how many turns to go clockwise to make it rich, start to then adjust slowly. Need an idea of how many turns to go in order to get car to run.

Thanks

250 Coupe · #5 03-11-2007, 12:31 AM

I would try 1/4 turn increments until it starts and runs well enough to find a CO meter.

Mine has about a 1/2 turn range between too rich and too lean so don't try for big adjustments even if it seems like you have been trying for a long time. You may overshoot the correct setting.

I don't know it it will work, but you could try pressing down on the air plate and turning the screw until you just begin feeling resistance from the metering pin. You will need fuel pressure to do this but don't press the plate down with the ignition on or you will flood the engine badly.

Michael

deportes · #6 03-11-2007, 01:38 AM

i will try that step. thanks

zcc · #7 03-11-2007, 09:08 AM

And make sure that u have enough fuel in the tank. I wasted 2 hour for the same problem u mentioned cuz I didn't have enough fuel in the tank!

cool · #8 03-11-2007, 09:43 AM

best way to deal with your situation is to get to a garage with CO tester and have it adjusted there to save you the wasted fuel with guessing game in adjusting and I assure you that you will never get to the right adjustment until you use a CO tester, time and time again people would rather think they can adjust it but in reality there is just NO WAY, you not only waste fuel during the adjustments you will also waste fuel while driving the car due to wrong mixture which cause wasteful fuel to no use.

deportes · #9 03-11-2007, 11:36 AM

After I get the car running, I will have the CO tested to minimize waste. I have access to CO meters at work. What CO values should I be looking for exiting the tail pipe?

250 Coupe · #10 03-11-2007, 01:01 PM

If it is a US spec car, it will be on the frame alongside the radiator. Mine is .2% - 1.5% at idle, vacuum connected.

Michael

deportes · #11 03-11-2007, 03:55 PM

Success at last. My wife started the car a few times for me while I messed with the hex screw, and the air inlet flapper 8 full turns clockwise was required to get the motor to start and stay running.
Now I need to make sure all vac connections and timing are proper so that I can smog the beast in Californication Smog test only shop.

just-n-time · #12 03-11-2007, 09:25 PM

Quote:

Originally Posted by deportes

Success at last. My wife started the car a few times for me while I messed with the hex screw, and the air inlet flapper 8 full turns clockwise was required to get the motor to start and stay running.
Now I need to make sure all vac connections and timing are proper so that I can smog the beast in Californication Smog test only shop.

The reason it would not run was it only got the cold shot of fuel,as you said the mix was way to lean,timing is not set manually. Do the vacuum thing if you can, do a smoke test to find any leaks. you can set the on off ratio with a meter(volt) search you will find a few post on how to.JNT