lart951

I have a customer with the following issue;

The 944 sat for 3-4 months, started and ran fine then a day later began stalling, backfiring and idling rough. This was mostly intermittent, though the fuel delivery would bog down under acceleration or load on the engine. Eventually wouldn't maintain idle for more than 2-3 minutes and became undriveable.


I had the fuel pump & filter changed. Ran better for about 5 minutes than began the rough idle & backfiring again.


Took the AFM off and noticed the black cover was loose and there was a flat spot where the current would go dead when we tested it. Cleaned some corrosion off the contact points, re-installed and the car runs better now but fuel delivery still stumbles in the 2-3k rpm range.


Definitely want to replace the AFM as the current one was damaged from the loose cover and heard the backfiring and rough idling can cause further damage.


Does the problem sound like the damper or the regulator needs replacing or should I just install the new AFM and go from there? Is there a way to diagnose a bad damper? I heard if the fuel pressure is high it's a symptom of a bad FPR. The pressure was 45 lb's before the new pump. Now it's 55.
Any help would be appreciated.

I think maybe it's TPS related or do you guys think the dme could be bad

PorscheDoc

Pull the vacuum line off the damper while someone cranks the car and see if it shoots fuel out of it. If so, then the intake is flooding with fuel and fouling everything out. I have seen that more times than I can count on the S2's. Also, if it is doing that, you will need to yank the TB and suck all the gas out of the lowest part of the intake.

lart951

Shoots fuel out of the vacuum port of the damper

C ANDERSON

Lart ,
Chedk the rotor , cap and wires My S2 wouldn't crank after it sat a few weeks had just been on a 500 mile trip too. finaly cranked ran a minute and quit . then a day or so later cranked but did not run well. found the rotor tip burned away and the little spring contact in the cap that touches the rotor totally burned way. then found the coil wire had burned away about an inch worth up the wire. Have no idea how I made it home on the trip. All the components damaged had around 12,000 miles.
Clifton

PorscheDoc

And there in lies your problem Replace the damper, spark plugs, and make sure to suck the gas out of the intake or it will just immediately foul the plugs again.

reno808

Lart can suck the fuel from the fuel tank from the TB i heard

C ANDERSON

Dang , that some suction , reminds of an old girl friend that could suck a tenns ball thru a 50' garden hose.

zerMATT951

Wow, things take a bad turn quickly around here!

lart951

you guys make me sick

zerMATT951

Are you sure it's not the fuel you're sucking out of the intake manifold that's making you feel that way?

reno808

LOL