tone3721

My 944 has been runnin like crap, idles very rough,i replaced cap/rotor/wires/plugs. Any idea why it could still be runnin rough????

livewirevoodoo

changing out the vacuum hoses made a world of difference for me.

allstar_02

If it smooths out at higher RPMs it is most likely your motor mounts. Just replace them.

caster951

I second checking/replacing all of your vacuum lines. I just went through that on my 83 a couple of months. Made a huge difference.

tone3721

thanks for the info, was wondering if anyone would eleborate on this. Ive thought maybe it could be a motor mount issue any idea what it costs to replace them?? I know theyre about 50$$ each. What would it cost me to take them in to be done? Also what would it cost to change out my vacuum lines? Ive also thought maybe its my injectors, could this be? It idles rough but seems to "gurgle" so to speak. It almost seems to be more of a bounce than a vibration, but it does go away at higher rpms.
thanx
tone

livewirevoodoo

The vacuum lines themselves arent that expensive.. Maybe $30 in parts.. For labor I'd figure on 1-2 hrs worth, whatever that will run you. Another thing to consider... How recently have the fuel and/or air filters been replaced?

FirstPorsche

... my "5th injector" post. Towards the end I describe how my 944S is now idling poorly. Some other people have responded for things to check.

Good luck!

Joe in CT

Rhoad Racing

I am very new to Porsches. However, I had a very similar problem with my N/A 240sx. It ended up being two things that was causing the rough idle and poor performance. Those pieces were the MAF and the distributer (the whole gear).
But livewirevoodoo's filter idea and the vacuum hoses are also great places to look.

hope this helps and good luck.

tone3721

Brand new air filter too, i could do the fuel filters,what do they run anyideas?

livewirevoodoo

Pelican sells the fuel filters (Part # F-110-253-06) for $17. Hard to get at location underneath the car, much easier with a lift. I brought the part to a local shop and the mechanic did it on his lunchbreak for $20.

Another quick thought.. Try some Chevron Techron Fuel Injector Cleaner... runs about $5 at Auto Zone..

tone3721

Yeah, ive put cleaner through it. Also, could it be a o2 sensor? The injectors click, doesnt mean theyre spraying mind you, but they click. prolly wouldnt hurt to replace the fuel filters, and vacuum lines. Ive also obeen getting kinda crappy gas mileage.

livewirevoodoo

try giving the shop manual at Clark's Garage a shot. He has compiled alot of great info (and step by step directions) on servicing 944's.

Im not knowledgable enough about O2 sensors to give a meaningful answer however..

I'd be interested in hearing how you make out if ya do decide to switch out vacuum lines and the fuel filter.

peanut

Boy you guys sure have some disposable income !

My suggestion would be to take the car to a Porsche dealership or specialist and let them listen to it. They do that everyday of their lives. Chances are they will know exactly what it is without even running any test and it probably won't cost a dime to get an experts opinion.

Of course if you want to throw money at the car by all means just systematically replace everything until the problem goes away Perhaps you could send me all the parts you replace I could sure use them

tone3721

Actually, I originally took my 944 to DJ at don jackson enterprises in phoenix az, he listened to it, and suggested i change my cap/ rotor, I did that. Starts better now, still idles rough. He also said it could be injectors, hence why I was asking about injectors on this forum......Maybe i should be posting on pelican anyway....ceannard sostnagh

peanut

sorry I didn't mean to seem critical of your approach its just that the answer given by most of the good folk on the forums is invariably r"eplace this" " replace that" that without any systematic checking testing and identification of the possible fault/s . There are 101 differant possibilities for your problem and simply replaceing everything related simply is too random and expensive in my opinion.


I have had similar problems on my car, once it turned out to be a very small head gasket leak putting a small amount of water in the engine which gave exactly the symptoms you describe .The car never overheated because the fans cut in and coped .

It could very well be just your engine mounts it happened on my car the first week I had her. Then again it could just as easily be the air idle valve , or highly likely an air leak on the air intake system at one of the hose clips ( I had that too and a new hose to the air idle valve cleared up my problem instantly.)
If you are going to replace parts at random in the hope of curing the problem I would start with the plugs first. They are cheap at least and a likely suspect.

A simple test would be to pull each of the plug caps off in turn on tickover and listen for any negligable change in idle speed or roughness.There should be a big drop in idle speed if everything is working properly .( Obviously use insulated pliers to grip the plug top) That might throw up a problem on one cylinder like a plug, injector, manifold leak, faulty hi tension cable etc. etc. You see at least that is looking for specific clues to the problem.

best of luck keep us posted.