Questions about 930

scudnik · 05-21-2003, 07:15 PM

Hey everybody,

Thanks for all the feedback I've received from the forum over the past week or so.... I looked at a 930 tonight and there are a few things I'd like your input on:

1) The cars smells like it runs rich. It also runs rough at idle until it warms up. These two may be related... Are these potentially major problems?

2) The stock air filter unit was completely removed (there was a BIG space where the filter housing usually resides towards the back of the engine bay on the passenger side), and the air filter that is in place is cylinder shaped (sitting upright) and sits directly behind the intercooler. I haven't seen this before. Does anyone know anything about it? Pros/Cons?

3) There seems to be some hesitation/roughness in the engine when cruising at about 2600 - 2800 rpm. Is this normal, as it's just sluggish until the turbo kicks in?

Thanks,

Shawn

Bruce M. · 05-21-2003, 09:38 PM

1) I suppose that they could be major problems, but I don't know that it's very likely. I have aftermarket efi on my 930, but from what I understand running rich is a pretty easy tweak of the CIS to take care of. Rough idle while cold is also pretty common, and pretty fixable, I bet, although it is sometimes hard to diagnose.

Of course, if you were actually going to BUY this car you'd get a thorough PPI, which would answer these questions for you as to your particular car, right?

2) People routinely replace the stock airbox with an aftermarket filter, often a K&N conical filter. There are mixed opinions as to how much benefit there is to this mod alone, but it's not a big deal either way.

3) There should not be hesitation as you describe. There should be "lag", but not hesitation or roughness. Different things. Get a knowledgeable Porsche mechanic to check that one out.

carmad · 05-22-2003, 03:54 AM

The rough running could be as simple as vacuum leaks which are easy to fix, I had this problem, but could be any number of things that are attributable to the CIS system. It should idle smoothly and there should be no hesitation.
Some people run with a rich mixture, to help prevent detonation if the engine has been modified for more boost.
Get a PPI before you make a decision will save mega $$$ in the long run. Trust me.

dean · 05-22-2003, 09:31 AM

I think if it is too rich that can cause it to run rough. My car is set to 3% and it sort of stinks.

Get a PPI

JEB · 05-22-2003, 09:51 AM

If it has hotter cams they may seem to make it run a little rough also.

RickM · RickM's Garage

Good advice, especially on the PPI. Is this car private or from Paul Miller or High Marques?

Ask for the service and any upgrade history.

1fastredsc · 05-22-2003, 11:00 AM

Take it to Powertech or ********. Mike at Powertech knows 930's like the back of his hand. Chris at ******** is the region tech specialist for 930's, so he obviously knows what he's doin.

scudnik · 05-22-2003, 03:28 PM

Thanks for all the replys... The car is out of town, though I have spoken to Mike at Powertech many times. He's been a great help...
I had a PPI done today, and the major things seem to be ok (including leakdown). The mechanics thought it may running a bit rough and rich due to one of a few things:

1) No O2 sensor
2) Ignition timing may be off
3) Distributor

Overall, the car is solid though needs a little tweaking to get just right...

beepbeep · 05-22-2003, 04:45 PM

Personally, i don't like 930's with those rice conical open filters installed.

First of all...it has been dyno-proved that OEM airboxes are very good design, and actually deliver as much or more HP while filtering much better than those bling-bling things.

So if you are going to buy it...consider finding original airbox. OEM box also has pipes for connecting crankcase ventilation, turbo-sump ventilation etc. It's a good thing to have!

There should not be any roughness or hesitation around 2800 RPM...engine is low C/R design and has very good manners. Torque isn't so bad down low either, it's just the fact that it's enourmous when boost arrives that tricks you into thinking that it's anemic at low RPM's.

If you are planning to buy it anyway, make sure to check that basic things are OK, like compression check, (maybe leakdown), CO-level, gearbox etc.

Ricer gadgets can be removed later...

As i said, the fact that PO removed OEM airbox means that he didn't really knew what he was doing but just went for general trend. That might give you some pointers towards how car was being used before and what to expect.

Good luck with your purschase!