No throttle response
 

I was driving hard for a 100 miles or so, it was hot out, and I had hardly any throttle response. The temp gauge was close to 100, I had 1/4 tank of gas. When I pushed the gas pedal, there was no response for maybe 3-5 seconds, then slowly it picked up. When I could stop, I filled up with gas and let the car sit for awhile. After that, it was fine. It's an '03 CLK 320 convertible, by the way. In an older car I'd have guessed vapor lock. Any ideas?

It could be dirt in the fuel injectors but doubtfull. It sounds more like your MAF is on its way out, remove and have a look to see if its got any oil on the sensor as you said it was fine when you left the car for a while which may indicate that the oil has run off the sensor allowing it to 'sense' the air flow once more.

If the MAF does have oil, then there is an engine problem as it should be dry and clean. Usual root cause for oily MAF are blocked breather nozzels on the fuel rail which you'll need to remove and clean out with some fine wire like 0.8mm welding wire or piano wire etc along with some carb cleaner helps.

PS you can clean the MAF gently but you need to takle the oil issue quick if this is the case before damaning the MAF permanently.

Thanks- I'll check that out.

Well no oil, that was good. Haven't had the issue again so I'll just keep monitoring. Thanks again for the help.

And why would a fuel rail have anything to do with "OIL" breathers? Is it a new german engineering deal? And if the fuel rail is allowed to breath then how does it maintain fuel pressure?

Still waiting for answers.

A1EK was talking about the clogged breather hose going to the manifold located by the fuel rail
https://mbworld.org/forums/clk-class...f-diy-fix.html

More than likely, it it a Throttle position sensor - TPS.

Easy fix, not too expensive.

Thanks!

So I haven't tried the TPS, but I did have the issue again the other night, seemed to happen after stepping hard on the gas. I stopped and turned the car off and then started it up again and the car was fine. Does this still sound like TPS issue? I'm getting an A service on Monday and don't want to over pay for something I can do...

most clk with symptoms like yours...hot...stalls...lags... is usually the TPS....one bolt and an electric lead rear driver side engine block...get OEM not China knockoff.

Thanks!