shudder

[theperkulator]

I have a 92 sl1 and I just took it on an over 1000 mile trip. I recently noticed that when I take my foot off the gas the car shudders a bit and if i barely touch the gas the car will shudder alot. This makes it shudder a whole lot when i am trying to maintain 25 mph. whats going on?

[sierrap615]

last year i took a 800 mile trip all highway averaging speeds of 70-75, however i was in the triple digits for a short while. my SL2 had about 160K miles at the time. during the trip, my 10 year old engine strut crapped out, and took the CV-boot with it, i didn't notice until my next oil change, however the ride was a little ruffer. my advice - inspect all motor mounts. there are 4, one on the top of the passager side of the engine, one below the first one near the oil filter, one under the battery/air box, and one inside the drivers side wheel well.

[theperkulator]

thanks for the advice but i know its not the motor mounts, its almost as if the car is missing or something, i took it into aamco cuz they have free transmission checks this month and they told me that my engine was giving a code 49 which meant a possible vacuum leak. i checked what i could but couldnt find anything and also replaced the pcv valve cuz it was getting kinda sticky but still nothing the studder, shudder, hiccup or whatever is still there!!! yaaaarrrrrggggg!!!

[sierrap615]

49. Idle rpm out of limit high (vacuum leak)

what is your idle RPM?

inspect all vacuum hoses and gaskets(includeing the hose to the MAP sensor). with any luck you may even be able to hear the leak. you can also spray carb and choke cleaner anywhere a vacuum leak is possible, if there is a leak, RPMs will drop. while you have the cleaner handy, clean the throttle body and IAC.

[theperkulator]

well the shudder fixed itself somehow it might have been bad gas or something. the only thing i did was put some fuel system cleaner in it...