No power at low RPM

[Junkyard4]

Hello,
I just purchased my first Pagoda Mercedes. 1966 230sl automatic. It had been sitting for several years and had pretty rotten gas in it but the car was able to run on it. I drained most if it out (as much as I could), put in 5 gallons of fresh and changed the fuel filter. The car runs much better but there is one big problem. It takes forever to get from idle to about 1,500 rpm. Once it's past 1,500 rpm then the motor takes off and has quick response in the gas peddle as long as you keep the rpm at a minimum of 1,500. So in other words, from standstill I can put the gas peddle to the floor and the car only creeps along as the rpm's slowly get up to 1,500 and then all of a sudden the car takes off and has plenty of power. Any ideas what the problem might be?
Thanks,
Paul

[alchemist]

Since the car was sitting for several years, the gasoline is well known to decompose and breakdown to reddish gooey materials. This causes damage to all parts of the injection system. You should not drive the car in such condition before you clean up the whole fuel system. I had a similar situation when I bought 67 230SL. Before attempting to crank up the car, I lowered the gas tank and took it for professional cleaning by a radiator shop. Then I replaced the strainer in the tank and the fuel filter before cranking the car. Ill bet that your strainer is clogged and this where you should start. I hope this helps.

[Junkyard4]

If the strainer was clogged why would the engine be running fine at higher rpm when it would be using more fuel? When I had the fuel filter canister off I turned on the fuel pump to flush out anything in the line and it had no problem pumping plenty of gas out. Could something be stuck in the injector pump?

[ctaylor738]

Lots of posts on all of these:

- do a fuel volume test
- make sure the injection pump rack moves freely
- make sure the throttle plate is correctly adjusted ("sticky")
- take the "linkage tour" and make sure that there is no slop in the ball fittings
- check dwell and timing
- ensure that the vacuum advance is working correctly when the throttle plate is first opened

[ja17]

Look out for a stuck WRD or injection pump rack also.

[Tyler S]

Sounds like the vacuum advance/retard diaphragm is not working. The mechanical advance starts to kick in around 1800rpm. Check te vacuum pod on the distributer and the vacuum line running from it to the throttle body.

Also is this an automatic?

[Junkyard4]

The fitting on the intake manifold for the vacuum advance was plugged up with carbon and not allowing the distributor to advance. The reason for all the carbon was because the timing was so far off it constantly was blowing back into the air filter. I adjusted the distributor and now it runs great.