R107 450SL cuts out when idling

[RaceDiagnostics]

Hi,

Just picked up my first ever Merc a few days ago, a 1979 450SL and have found that it is not happy to idle once the engine is up to temperature, it cuts out when moving into drive or reverse from park or when bringing the car to a standstill.

Any suggestions or hints where to look for problems.

Thanks

 

[Druk]

Get it on a machine and check the CO. ~Only adjustable at idle but has a significant effect.

 

[RaceDiagnostics]

Thanks, but what and where is the adjustment?

I bought a workshop manual CD from ebay but am still waiting for it to arrive.

 

[Druk]

Depends on your injection system. Probably CIS. Plug between the big air flap and the fuel distributor head. Long Allen key down there for adjustment in VERY small increments. Set it rich then reduce to correct setting. Don't put downward pressure on Allen key cos setting will be wrong. Replace plug...

Only data I have is American. CO 0.5 to 2.0. Idle 750.

 

[RaceDiagnostics]

Thanks, will give it a go next weekend.

 

[RaceDiagnostics]

Also found a (US) Hanes manual which I have ordered, looking forward to it turning up.

 

[RaceDiagnostics]

I finally got my Haynes manual and Mercedes workshop manual CD on Saturday morning.

I found that there were two adjustments, the idle speed control and the CO idle control, the manual indicated that after adjusting the idle speed the CO needs to be adjusted to bring it into spec, however as I don't have a CO meter I just corrected the idle speed and left the CO as is.

Next I need to add a CO meter to the list of "tools to buy".

 

[SilverSaloon]

I can recommend D&G Autocare in rumblewell Jim. The mechanic who worked on my car (Tiff) is a member of this forum - my 280SL is now running best its ever done after the mixture and idle has been set up right. Well worth it and didnt cost very much either. Leads and plugs were replaced at the same time.