C230 PROBLEM, HELP.
 

NO CEL, c230 1998, 124,000 miles

FELT A KICK TWICE AT 75 M.P.H. CRUISING 2 TIMES LAST WEEK, FELT IT 2 TIMES AT COMPLETE STOP TODAY WITHOUT CAR MOVING at red light.

FELT A KICK WHEN PUTTING INTO DRIVE AND REVERSE AND STRANGE RESPONSE FROM GAS PEDAL, MEANING NO RESPONSE WHEN FLOORED AND THEN RESPONSIVE A LITTLE YESTERDAY, AND THEN NORMAL. Turned off engine, left it alone for 4 hours and when started, back to normal. I cleaned throttle body 2 years ago myself.

I'M THINKING FUEL PUMP,F.P. REGULATOR, RELAY BUT NO STRANGE NOISES FROM REAR OF CAR LIKE I HAVE READ FUEL PUMPS DO. HAS NEVER DIED ON ME.

MECHANIC SAID TO WAIT TILL IT DOES IT ALL THE TIME??

I DON'T KNOW WHAT IS UP?

I have noticed a stumbling at stop light on occasion, but car not turning off and revs are normal and not high.

Changed MAF AT 40,000 MILES, NOW AT 123,000 MILES.NO OIL LEAK. NO HEAD GASKET LEAK.

SORRY for ALL capitalizing, just frustrated, and when mechanic tells you have to recreate it.....this is all intermittent!!

Got to find a good mechanic that knows how to diagnose these things in Houston, don't want to start guessing and changing parts....expensive and wont fix problem unless lucky!

Yeah, you should lay off the caps, some people won't even respond if you are using caps. You describe some different things. An occasional stumble at a stop is normal air pump test, once per warm-up cycle. I am not sure exactly what you mean by kick. The most extreme symptom you list I think is when the gas pedal did not respond. Of course the first question is about the check engine light and codes.

Is it going into the "limp" mode? Is that what you are describing as "strange response on acceleration"?

sounds to me like throttle body going south[electronic accelerator] very easy to change although a little pricey.

Today in park, rpm went up to 900 down to 400 and back to 700 rpm.

"Kick" is like you hit gas and off pedal quickly, or when cruising do the same.

No CEL so not possible emission, like o2 sensor.

David,

What is the failure mode of the throttle actuator? I would think it should be very reliable. Is it just a stepper motor and some gears?

WELL, PAID 100 bucks today to have a mechanic tell me that it is the THROTTLE BODY ACTUATOR AND possibly the TRANSMISSION MODULE, after hooking car up to his computer.

What does the transmission module do?

David, I could have saved 100 bucks with you, ha, ha!!

Where to buy one for good price, and a how to change it myself are next 2 questions?

replace or clean?

I CLEANED IT and things are better, when do you change those as opposed to clean?

SPOKE TOO SOON.

On freeway today cruising at 65 mph and felt 2 short kicks form car, like hitting the accelerator hard.

Guess that throttle body cleaning did not help.