Sometimes, esp when the engine is not warmed up, I hear the carburettor going "pop" and naturally, there's a loss of power for a split second. What could be wrong with it? Too rich a mixture? Any tips for adjusting this carb? Tks.

What you describe sounds like a lean condition. Check to make sure the choke isn't pulling off too early.( is your mixture ok otherwise?) Another thing that can cause the carb to "pop" is ignition timing being too far advanced, but I doubt that this is an issue at this point.

If this pop also occurs when warm, then perhaps your lean condition can be caused by a vaccum leak. If it occurs upon acceleration, then I would guess poor performance from the accelerator pump. (just a few more thngs that came to mind)

Hope this is helpful
-Larry

------------------
03/83 300D
07/73 280




[This message has been edited by Larry Delor (edited 01-06-2000).]

Hi Roland,
I'd agree with Larry. Whatever the cause is,you have a lean condition. When the "pop" comes from the intake,its a lean or poorly atomized mixture. When it comes from the exhaust,its too rich.
I had a 78 230 for a few years that had a similar problem when it was cold. Since it went away after warm-up I figured it was just fuel condensing on the cold surfaces inside the intake. Eventually I took the intake manifold off and found a large chunk of carbon where the EGR connected to the manifold. I cleaned it out and the car was fine afterward. I figure the carbon chunk was soaking up fuel like a sponge(okay,a hard black sponge)when the car was first started.

------------------
W.R.Durrance
ASE Master Tech
Mercedes Tech 19 Years

I am completely unfamiliar with the carburetors on this particular car but from your description and my previous experience with carburetors in general, I agree with the others on their diagnosis. What you have is a lean condition. If this carburetor has a float (I have never seen a carburetor without one), I would suggest verifying that the float level is correct. Do this after verifying proper pull off of the choke and proper operation of the acceleration pump as Larry Delor suggests. It would also be a good idea to make sure you don't have a vacuum leak. Check for the obvious: loose vacuum hoses, etc...

A SUGGESTION TO CONSIDER FOLLOWING AT YOUR OWN RISK AND DISCRETION:

I have successfully searched for vacuum leaks in the past by VERY CAREFULLY spraying a SMALL amount of carburetor cleaner around various seal areas of the carburetor and intake manifold with the engine idling. KEEP A FIRE EXTINGUISHER HANDY just in case. DO NOT USE STARTING FLUID (ether). When you hear the engine idle speed increase, you have found your leak. AGAIN, THIS IS ONLY A SUGGESTION. TRY AT YOUR OWN RISK.

Best of luck.

Thanks for all your replies. If any of you could point me to any good resources/references for the Stromberg 175CD carb, will appreciate it too.