DaveS

Over the past couple of days, I noticed a loss on power/sputtering on 2 occassions and wanted to know if these were a) related and b) avoidable, due to better driving habits.

On the first occassion, I had the non-warmed up engine up to some fairly high (5,000) RPMs. The engine was only operating for a couple of minutes and I couldn't resist taking on an Audi 8 that was egging me on. Shortly after that, I was in 3rd gear and let the RPMs drop to below 2,000. The engine sputtered pretty significantly. It picked back up when I downshifted into 2nd and hit the throttle. Could I have done any damage with my foolhardy behavior or was this the result of low RPMs regardless?

On the next day, I didn't downshift from 3rd to 2nd as I approached a toll booth on the highway. Same sputtering happened.

Besides having learned my lesson about downshifting, any thing else going on here that I should be wary of?

91C2wrencher

Davo, have you looked at your distributor belt recently? You WILL want to do this upgrade very soon as these cars are aging now and all of them need to have this service performed. I might add that I had mine done by Steve Wiener right here at Rennsport, and very nice job he did as well! Other thoughts include did you fill up with some cheap gas like Mobil?(my car hates mobil)

Randall G.

Hi Dave,

I don't think not having the car warmed up fully had anything to do with the sputtering. For example, I test drove several then-new 964s before purchasing my car, and the salesmen ran the cars hard right out of the box. May not have been good for the cars, but they ran perfectly.

I would check the distributor belt, as already suggested by 91C2 wrencher. I would also replace the (cheap) DME relay, if you haven't already. Keep the old relay as a spare, if it doesn't correct your problem.

Best of luck!

J-McDonald

I wouldn't discount the car not being up to operating temperature - my 964 won't pull when cold. It stutters and bucks. I've tried to adhere to the rule that you should never exceed 4,000 rpm until the engine is up to operating temperature. Also, I allow the car to idle for at least 5 minutes before driving it on its first run of the day.

I've also made the mistake of trying to accelerate in too high a gear, with the same response.

Randall G.

Hi J-McDonald,

Something may not be quite right on your car. I drove several of these cars when new, and they all ran flawlessly when cold. My own car has never sputtered when cold, even at low RPMs. If it did, I would think something is wrong with it. The only time I have ever had low-RPM break-up is when the distributor belt broke.

If you went and test drove a new 996 today, you wouldn't expect it to "stumble" out of the parking lot until you got the car warmed up, would you?

I believe the computers on these cars--in conjunction with the cold start inputs--keeps them from driving crappy when cold, like our father's car did.

FWIW

DaveS

My thought was that the rapid transition between high RPMS in a low gear to low RPMs is high gear would cause that effect.

Am I that far off base? Is the engine that strong generally?

Randall G.

Hi Dave,

You can find a DIY for checking your belt on John Mile's website, under the technical section:

<a href="http://www.porsche964.co.uk/" target="_blank">Link to John's Site</a>

&gt;My thought was that the rapid transition between high RPMS in a low gear to low RPMs is high gear would cause that effect.

&gt;Am I that far off base? Is the engine that strong generally?

Hmmmm ... all I know is that these engines do not sputter when they're running right, no matter what you do to them. Well, okay, they will sputter if you hit the rev. limiter.

christian

The most common cause is ignition caps and rotors as well as spark plug wires. I don't like the fact that there is still so much mechanical stuff involved. Pull the ignition caps and have a look inside.