Hello,

The car. 83 GL SW 1800cc 5 speed

The Problem: Engine Stumble at 1200 rpm

 

My Sube starts well, idles well , seems to have good power, but when you let out the clutch and accelerate in any gear, a annoying stumble happens between 1000 and 1200 and then runs smooth to 3,000 or 3500, then shift and I get the same stumble at lower rpms. What do you experts think it is.

SC

Vacuum leak at the carb base or primary throttle shaft would do that.

 

Incorrectly operating accelerator pump might do that.

 

Basically the carb is having difficulty transitioning from the idle circuit to the slow speed circuit.

 

GD

As GD said that sounds like a carb problem. But another thing to look into is the vacuum advance on the distributor. That could cause a stumble like that too. Mine was busted for awhile and caused a similar stumble.

Both previous post have merit and should be checked.

 

But

 

I have seen Seafoam work some magic in these cases.

 

It may take 100 miles to work though.