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Any ideas on this.

Old 11-07-2010, 07:31 PM
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MUSSBERGER
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Default Any ideas on this.

In the 930 today I was on a ramp going from Rte 18 (highway) to the GSP. A long sweeping right hander. I downshifted to third and was going about 70 and went to accelerate onto the parkway. All the sudden it starts to hesitate. Catches again and goes away. A little further and it actually bucks a couple of times and goes away. Get off the parkway in case it dies completely and it seems fine. Get back on the parkway to get it home and everything is fine.

It did this a couple of weeks ago under the same circumstances.
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Old 11-07-2010, 08:56 PM
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Amber Gramps
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Where is the signature that says "check your F-ing grounds" ?

Any chance that centrifical(sp) force had something to do with this? Loose wire somewhere?

How's the fuel level?
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Old 11-07-2010, 09:14 PM
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Ed Hughes
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I'd look at fuel pick-up for starters.
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Old 11-07-2010, 09:24 PM
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Sounds like my motorcycle when it starts to run out of gas. Switch it to reserve and everything goes away. I'd say Ed is right, and that long right turn was probably the cause.
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Old 11-07-2010, 10:05 PM
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MUSSBERGER
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First time it did it with a full tank. Today was at two thirds. I going to have a look at the wiring on the fuel pumps.
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Old 11-07-2010, 11:17 PM
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As weird as this may sound. I just had a issue like this and it ended up being a bad coil. I replaced the coil and what do you know, it was perfect again.

Just a thought. I hope that it helps.

Erik Johnson
(303) 895-4828
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Old 11-08-2010, 12:13 AM
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joseph mitro
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sounds like fuel starvation.

first thought is fuel pickup? fuel filter? fuel pump?

vacuum lines related to turbo?
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Old 11-08-2010, 12:51 AM
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Yeah, it's got to be either fuel or spark. Check the usual suspects. I would start with spark though, since the problem comes and goes.

Spark
1. ground
2. rotor & cap
3. plugs & wires
4. coil

Fuel
1. Fuel pressure
2. filter
3. pump

That's all i got gabs
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Old 11-08-2010, 06:07 PM
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I chased a similar problem on a 930S. After lots of diagnosis, it came down to the coil(which can be a hard diagnosis to make). It wasn't a cheap coil. IIRC, there is a different coil on the turbo cars. if not, I presume a turbo can be hard on a coil.
I would also say that a fuel pump has been known to cause similar problems. Peter Z recommended a pump to a guy who's car was doing this on the track in certain turns-was not a turbo however. A known good pump is always nice to have and the old may be kept as a spare. You know the routine MUSS.
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Old 11-08-2010, 06:18 PM
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since it is so intermitent you can send the car to me and I will diagnose .. could take a couple of years though ..
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Old 11-08-2010, 06:21 PM
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yes. It take a village to own a Porsche. (In german, "v"s are "W"s and thus...it takes a willage). I'm here to help.
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Old 11-08-2010, 06:38 PM
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MUSSBERGER
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Originally Posted by whalebird View Post
I chased a similar problem on a 930S. After lots of diagnosis, it came down to the coil(which can be a hard diagnosis to make). It wasn't a cheap coil. IIRC, there is a different coil on the turbo cars. if not, I presume a turbo can be hard on a coil.
I would also say that a fuel pump has been known to cause similar problems. Peter Z recommended a pump to a guy who's car was doing this on the track in certain turns-was not a turbo however. A known good pump is always nice to have and the old may be kept as a spare. You know the routine MUSS.
It does feel like a fuel issue. I had just filled it at a place that probably doesn't sell a lot of premium and thought "what kind of crap fuel did I get" but then it cleared up. I am betting it is fuel related. I just have to follow the steps. (I hope it isn't something in the tank)

BTW. Ice, your generosity is most refreshing.
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Old 11-08-2010, 06:51 PM
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dshepp806
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I had this very same thing happen to me yesterday in my '89. A few years back, I introduced a a Techron treatment into my fuel tank...I don't recall the exact mixture, but dumbarse me decided to concentrate this mixture by adding a 20 gallon treatment to <8 gallons of fuel....I drove the dog out of this car (after the treatment) for a good hour and 45 minutes. The next morning, I took her out and discovered some weirdness (intermittent) with hesitation at higher RPMS,...all corrected by letting off the gas. It would come and go...As I ALWAYS plan for an oil changeout after such treatment, 2 days later I get her on the rack,..change the oil, oil filter and fuel filter and all was well...

Just yesterday I did the same thing (it's time) and the day after, experienced the VERY same thing. Granted, I may have introduced this by using a concentration OUTSIDE of the manufacturer's recc's. I've not added gas just yet and may take her out this afternoon and see if she strands me!!!!!!!!!!!!! I have plans to add gass then check it out,..oil change is slated for this weekend.

I'm one of those that keeps the plugs, distributor cap and rotor changed somewhat frequently (much shorter than the Porsche intervals) and it's time for that (in my world). I've never changed my coil out since ownership but have desired to do so (resistance checks on the primary and secondaries look OK, yet I know this isn't a pure confirmation. I always had reservations about my spare Brazilian coil.....wish I could look at the electrical waveform being generated by the present coil on an analyzer, as this could give me data on waveform integrity (loading, etc.).

Just recently developed a very small fuel leak issue at the crimp side of the high pressure fuel line as it enters the tunnel. No fuel delivery volume checks yet, nor pressure test, not pump current draw......but did plan to go ahead and replace the fuel pump while in there ( as Bird suggested). Just trying to determine this "routing" stuff and avoid the tunnel work.....it may be the case where something has let loose down there....don't know...what I do know is that the Techron add , in concentrated approaches (dumbarse me) have yielded some strange results.

Still much work to do (fuel, ignition, etc.)...For all I know the injectors may not be up to par and should have these babies sent out for rework..
Clearly this may have nothing to do with your situation,..back to the other posters' recc's.

Just strange that I had the very same issue just yesterday.....thought (for a moment) that she was going to strand me.......never cut off, however.

Hell,..it could be ANYTHING...and all will have to be checked (fuel pressures, spark, coil, (even) DME, distributor, rotor, etc.)

Many experienced guys who will "set you free", here on this great Board.

Just wanted to share...

Best,

Doyle
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Old 11-08-2010, 06:53 PM
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Hopefully, something simple (however)...like crappy gas....I hope that's all it is for you, Mussberger.

Doyle
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Old 11-08-2010, 07:25 PM
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Ed Hughes
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I'd fully expect to have a poorly running car if I put 2.5X the amount of Techron for a given volume. I only add the stuff at the gas station prior to filling up.
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