924Board.org

[Porschejag]

I recently saw a ’87 944S advertised on the Technology Superhighway (or the internet, as some refer to it) and I decided to go give’r a test drive. On the way, I told myself that I wouldn’t actually buy it since I already am indulged in ongoing projects (the 928S mainly and, obviously, continuously tinkering with the 924S), but decided that I would potentially swap my 300zx keys with them… you know… if necessary. Thanks to the CarFax, they claimed that it was a one owner car. From the looks of it I buy that claim; it was reasonably good-looking for the age/asking price. I didn’t notice any massive problems from the go-around look. The hatch seemed fine, no battery tray issues, and inside the car no mildew-y smells. “So far, so good” I thought. After waiting for the maintenance man to go put $15 worth of gas in it, I got the keys and took it for a test drive that lasted for about an hour.

I have to admit, I felt like I was cheating on my little 924S. You know… secretly fooling around with the shinier, more “prestigious” model… whilst leaving the wife, who, let’s face it… could use a good re-spray to get that sexy appeal back, at home. Oh, and they were sure to mention that they put a new waterpump in which was, “Pretty expensive.” No mention of a timing belt job, though.

Just a side note< did you know that most second hand auto dealers throw away previous owner’s maintenance records, in order to ensure privacy for the previous owner. I have actually never dealt with car salespeople, so maybe they were just pulling a fast one on me. Luckily, all of the salespeople left me alone the whole time I was there (except to give me the keys and dealer tag, but we did some quick conversing at the end of my affair), so I didn’t get aggravated with sales tactics at all.
To wrap this up and to get to the point at hand: The car was great all around, but, whenever at idle, it ran pretty poorly and rough. I don’t think that the motor mounts are the culprit, because it didn’t feel like a shaky earthquake. Instead, the revs would go down well past the 850RPM idle speed (I think that is an accurate number… I know it’s around there somewhere). I figured that it was just the car warming up at first, but it seemed to get worse the more I drove along. Hell, at one point… I downshifted and hit the brakes pretty good and the thing shut off. Again, it was perfectly fine once in motion and ran very well. I have a few ideas (mostly generic causes) of the problem… but thought I would shoot a post on here so the fellow Porschian’s could toss out every possible issue. I should also mention that it started up just fine after the good test drive jaunt.
I’m still thinking about potentially swapping keys. So, you Porsche-God’s should tell me all the bad possibilities lurking within that engine (which was nicely detailed, mind you).

[Ian89C4]

o2 sensor?
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Ian Edgerly
North Carolina

Current:
1981 924 SCCA/ChampCar Weissach Race Car ("Serenity")
1987 924S ChampCar Endurance Car ("Der Weg")
1980 924 Euro ("Wahala")

[edredas]

Poor idle can be caused by cracked/broken vacuum lines, a worn resister track in the AFM, or a bad Fuel Pressure regulator.
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'84 944 -White, Brown interior
'84 944 -Red, Automatic
'86 944 -Garnet, Fully loaded, Koni suspension
'87 924S -Red, 300hp 951 swap
'87 924S -Red, Project Car
'88 924S -Red, Daily Driver

[Porschejag]

Hey! My guess was faulty fuel regulator, too. I also thought that it could have been spark related, but struck that idea out pretty quickly. And- the visible vacuum lines looked in pretty decent shape. It definitely seemed like a fuel problem to me.
With that said, wouldn't a bad fuel regulator make the startup seemingly rougher, too? Because the car cranked without hesitation just about every time I started it.

[edredas]

[Harm]