Porsche Enthusiasts Club Forum

Been trawling around today as the weathers crap & the wifes got the flu.
Found this which I think bears repetition. In the States of course. Well replacing the pressure reg & damper gave me 15 horses straight out on the dyno so maybe some of the rest is ok too? Beginning to suspect my AFM as somthing is causing my mixture to be way out. See what you think.

What would make your 944 run faster?
1. Change all fuel injectors to NEW and not rebuilt.
2. Change the fuel pressure regulator and fuel dampner. If your engine oil smells like fuel, it is further proof of malfunction.
3. Make sure your fuel filter is new
4. Buy a high performance ignition coil and plug wires (do not install funky looking plugs. OEM works the best) Beru silver "Silverstone" plugs are the best choice.
5. Change gear lube oil in your manual transmission to SWEPCO high grade racing blue oil
6. Change your paper filter box to an open K&N system with header’s heat shield installed
7. Install a Throttle response wheel to your throttle body
8. Install a new injector boot as well as new rubber hoses running to the manifold. Old rubber is usually hard and brittle. Microscopic cracks leaking air will lean out your mixture creating "underload" reducing engine’s pick up power.
9. Remove the AirFlow meter. Holding it in your hands, move your ear to the plastic top . While listening, move inner vain door by pressing inward. If you hear faint scraping or squeaking noise, replace the unit. Yours is no longer sending correct information to your DME unit. The inner potentiometer has been scraped away.
10. Hard to start, rough idle? Examine or replace your reference sensors. There are magnetic pegs on the flywheel passing by the ref. sen., sending piston position to the DME unit. When information is inconclusive, DME will refuse to send the current to the coil, thus resulting in “no start”. In most cases the system fault is the result of the pollution. Small metal particles from the clutch and the flywheel are culprit. Consider changing these sensors and cleaning the side of the flywheel.
Above changes will significantly improve your engine performance. Without these changes you cannot continue with further modifications. All listed parts must be replaced. Do not assume they are ok. If they are original, they must go.

Interesting list...!!! Why dont you start by cleaning the side of the flywheel...................................

My 10 pence worth...

1. If they are knackered then yes, otherwise an injector service, but normally only affects smoothness not performance.
2. Unlikely, they don't tend to age, when they fail then it's no start!
3. Good servicing & can help the fuel pump last.
4. I ALWAYS use NGK plugs, the 944 does seem to be sensitive to ignition quality, especially as regards starting.
5. Worthwhile made a staggering difference to mine.
6. I don't use K & N any more as I don't think the gains are worth the disadvantages.
7. Not sure whether it makes a difference, mine has one, others don't.
8. If they leak, then fix it, microscopic leaks cobblers!
9. Never heard of this diagnosis technique, mine was so far out it failed the MOT on emissions! Can affect low speed drivability, mine did, high speed unaffected.
10. Cobblers they'll only cause non-starting.

Because it's raining. And its warmer in here armchair tuning! But I will investigate later.
Jim Some of these I already did.
1 before I got the car
2 15 horses better! Dynos don't lie so must be somthing in it!
3 I don't have one!
4 replaced for oem
5 done by previous owner
6 Don't believe it myself
7 Car has one already
8 Havn't checked it......yet
9 ??????? only place the fueling is correct is at 3000rpm so somthing must be wrong.
10 suggests cleaning flywheel. but my car starts already so maybe 9

Considering the maxhp motronic tuner to remap it but since its fairly standard it shouldn't really need one! Looking at the AF ratios from the dyno day most of the cars are loads better in the fueling than mine! Sure a remap will help it a bit. But if the AFM is on the way out it may be short lived.