Idle vibration fix?

[jborchel]

I once owned an 87 944 that was one of my favorite cars among close to fifty I have had. However, one of the things that disappointed me was a very rough idle that was normal with the 944 and then the 968 idle. I'm thinking of buying another one if time has fixed the problem through some type of engineering fix from the after market. I'm thinking of a chip change that may have been developed to fix the problem. Is there such a thing? If so, I'm going to start the hunt.

Jack

[wvicary]

They should not idle rough. One fix to a very common problem was upgrading the engine mounts to the turbo mounts.

[jborchel]

The bad engine mounts used to be blamed back in the day as the source of the rough idle problem. It may have contributed but I recall having the ignition or fuel injection settings tweaked by a friend who was an authorized dealer mechanic to the point that the idle smoothed out considerably. However, this out of spec and illegal tuning eventually caused what seemed like uneven running. I had him reset it to spec and lived with the idle problem. Since that time(the late 80's) much has been done with after market chips that are designed to do different things to the performance of the engine. I was hoping that there was one to smooth out the rough idle. If it really is an engine mount problem did Porsche ever issue a newly designed mount for the 944/968?

Jack

Edited November 16, 2010 by jborchel

[flash968]

this is all specifically related to a 968:

there are a number of things that can generate an uneven idle or vibration in a 968, not the least of which is misalignment of the balance shafts - mechanics miss this all the time too, as many of them only look at the marks on the pulleys, and not at the keyways, which results in the lower shaft being off by a lot

motor mounts are known to fail, especially the exhaust side, due to the heat - there is a spec to see where yours are

rotors and caps wear out fast (often in as little as 10k miles), and can quickly contribute to a hunting idle and slightly rough running at low rpms

chips don't really address the idle

a dirty MAF can do it too - use only MAF cleaner and do not start the engine while it is wet

tiptronic cars idle fairly roughly no matter what

Edited November 16, 2010 by flash968