86' 944 Turbo not putting down power

[Aero06]

Yesterday, I made a four hour drive out to meet the owner of a 1986 944 Turbo. We spoke for a few minutes, I’d already paid a shop remotely to perform a prepurchase inspection on the car, which was an ordeal in and of itself, and probably a waste of money given they told me the car drove properly and was in fine condition.

We took it out for a test drive, and for the first ten minutes it was driving fine, I took it through some streets and noticed no problems, aside from a slight rough idle. On the highway, I felt the turbo making proper power, the boost gauge hopping up and down as I shifted between fourth and fifth. There were absolutely no red flags or things that made me suspect there might be an engine problem. We exited on the offramp and took two lefts to get back on the opposite direction. As I accelerated onto the onramp, the engine began to cut out, like I was pressing in the clutch, and it sort of flickered like this, the engine putting down bursts of power. The engine sounded fine, like it was making power, just not transferring it, but I was switching between gears, trying to get some power to the road, and it shifted just fine, no loose linkage feel or strange vibrations in any of the peddles or scraping sounds between shifts. Eventually we got to the shoulder, and managed limp the car back to an offramp, getting power down for a few seconds at a time, the car shuddering like when one doesn’t shift properly.

The owner mentioned he had gotten water on the distributor cap when cleaning it that morning, and had trouble starting it that morning until he removed and dried it, and that it may be the cause of the problem, not firing right. That could be, however I didn’t see or smell any smoke that might come from an engine burning rich if it wasn’t firing properly. There was no smoke coming from the engine bay, and no leaks underneath. The owner apologized, and promised he would look into the issue.

I only have the experience to describe the problem, but does this sound familiar or indicative of a certain problem to anyone? The owner has been very fair and upfront, and the car is in fine condition, I’d love to buy it from him but I’m not looking for a project right now, and would prefer to drive it home rather than have it trailered.

[kdjones2000]

Might be a vacuum leak, one of the speed/reference sensors going out on you, spark plug wires.... Many things.

Hard to tell via a forum.

[mpescione]

Check that the insulation in the muffler is not loose and blocking airflow

[smokintr6]

Originally Posted by Aero06

I’d love to buy it from him but I’m not looking for a project right now

This will sound condescending, but as someone that has owned 944s for more than a decade: They are all projects at some level, and It might not be what you're looking for.

Your description of the engine "sounding like it's making power but not putting it down"... makes me think it's clutch related. Is the tachometer increasing, but the actual speed of the car does not increase?

[full quack]

I don't want to presume anything or make lite of your situation, but by the way you describe the driving experience,...maybe, just maybe your automotive experience level is not where it should be for considering the purchase of a 31 year old car.

You don't just take these to Jiffylube and the like for maintenance and repair. If you are not adept at working on cars yourself, then at the very least you will need to find a shop that knows about older Porsches...and get ready to pull out the VISA card.

Liking older Porsches and owning them, can be two completely different realities.

Mark