Lol...no, actually I was thinking I was hearing of a whole new bit of automotive lore.
Thank you for all of your suggestions. I really appreciate that you've take the time to write them out! I think I forgot to add one salient point regarding this particular 164: it only has about 63K miles on it and the former owners took good care of it. So lots of things which are typically cracked and broken on other older Alfas are in great shape on this car. "Rockin' the engine" has been a big subject of discussion. I will clarify. The engine moves hardly at all, the mounts all seem solid. At first, I noted the engine RPM change when I put a lot of my weight (I am 170 or so) on the plenum while leaning over to inspect the idle air controller and back (1-2-3 cyl. or "passenger side" for 116 owners) plug wires. "Ah-HAH" I thought, suspecting one the hoses attaching to the plenum of allowing un-metered air in. Further study revealed this to be an early 1991. The plenum is solidly screwed to the valve cover...zero wiggle room. Then I noted that I could re-create the RPM increase by pulling up or pushing down on the edge of the front (4-5-6/"driver side") cylinder bank. Or any other portion of the engine by which you can grasp it and apply strenuous force. Recall that the engine barely moves...just what is natural with healthy motor mounts All of this sent me on a poking/prodding/wiggling (p/p/w) spree. Here are some things I can rule out: - Plug wires. No amount of p/p/w on any of them had any effect. The engine also runs very smooth at any RPM. There is no oil in any of the wells. - Idle controller. It was my #1 suspect at first. The connector is good and solid and clean. I removed it and inspected the rubber seal. It is showing its age but not deteriorated and it seems to fit fine. Again, no amount of p/p/w on it caused the surge or any other change. - Throttle position switch. It clicks with the slightest application of throttle and shows no signs of tampering. Suspect items: - Wiring to the throttle position switch. A failed switch can cause the engine to idle at 2000 RPM. And my engine is doing just that for short amounts of time. - Throttle position switch. Yes, I know its in the 'rule out' list but just because it clicks at the right time doesn't rule out the possibility that there is some other internal defect. - Air leak on the main intake duct. A fellow Digesti noted that my problem sounded similar to something which happened to him: the engine position shift opened and closed a crack in the big duct. This makes a good deal of sense when you consider that the engine can move about on its mounts but the air box is bolted to the chassis. Next weekend I plan on trying to check these out along with your "Suggestion 2" and "Suggestion 3". I sincerely hope that I'm not experiencing anything to do with you suggestion 5...have you seen the prices of new fuel pumps for these cars? Thanks again, - Eric H., Marietta, GA On Jan 29, 2012, at 10:05 PM, [email protected] wrote: > [email protected] wrote: >> Suggestion 3) Do a leak check with brake fluid or starter fluid around the plenum area while the car is running. You may find something of interest. > Yow! I meant Brake Cleaner, not "brake fluid." But you knew that.... > > Michael -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
