TMc993

997 C2 NB with approximately 68,000 miles.

• Car had plugs installed @ 42,00 miles (Per paperwork provided by PO).
  
• Has never had plug wires or distributor caps replaced

Recently, when the engine is cold, there has been the slightest "stutter" on the first acceleration run up of the day...After that, no issues.

Until yesterday...

1. On Friday I drove in some pretty wet conditions. It ran great all day. Parked the car indoors Friday night.
   
2. When I got in the car Saturday, it took longer to start than normal, idled rough and stuttered badly when revvved to 3200- 3400 RPM, but then would clear up past 3400 RPM.
   
3. Car sat in the rain all day Saturday and took longer to start at the end of the day. Again, the engine stuttered badly @ 3200-3400 RPM and then cleared up past 3400 RPM.
   
4. Today, the weather was dry. I washed the car and then started it. Again, hard starting, rough idle, bad stuttering @ 3200 - 3400 RPM.
   
5. Slowly drove up the road, keeping the revs under 3200 RPM and after about 3 minutes the roughness smoothed out and the stuttering disappeared. Re-started easily, idled smoothly, no more stuttering.

No smoke black or white on start-up. No strange sounds other than the stuttering....

I'm thinking a mosture-related ignition problem.

I'll put a code reader on it tomorrow, but was wondering if it isn't time for plug wires, distributor caps, etc.

An ideas or suggestions would be appreciated.

Terry

cabrio993

Terry, it sounds like moisture inside the distributor caps. Did you check them?

TMc993

Sergio,

No, I haven't had a chance to check anything yet...This is one of those things that I've read about on RL, but not paid a lot of attention to because I haven't experienced it...All of a sudden, it's important.........I'll search on that and see what comes up.

Thanks,
T

J.B.H.

Sounds like Cap and Rotor Replacement time

Falcondrivr

I know you don't want to hear this, but it's the plug wires. I had a very similar issue. I replaced my wires, caps, and rotors when my engine was out last month. My wires only had 50,000 on them and they were in terrible shape. Caps and rotors didn't look that bad, but I had the parts...My issue went away. I'm 100% sure it was the wires. You could see where the insulation was breaking down.
There's a diy where you go out and mist the wires with a spray bottle at night with the engine running and the garage lights out. I'm betting you'll get quite a light show....

cabrio993

Yeah, I hear you. I have experience the exact same thing that you are describing with my previous Alfa. It ended up being a cracked rubber boot in one of the spark plug leads. Whenever I drove it in the rain, humidity would get in there and condensate inside the Cap creating all kinds of havoc.

Take the caps off and check for slight condensation of rust on the plug poles or the rotor tip. If you find rust and/or condensation, you need to find the source. Look for cracked rubber boots and/or make sure that are seated all the way into the cap.

1pcarnut

Very first thing I would check is the belt between the two distributors. You do NOT want to drive the car if this is broken. If not broken then the above suggestions should be checked.

Falcondrivr

Definitely check that by unbolting the bottom distributor cap and seeing if you can spin the rotor. If it spins, your belt is broken. However, your symptoms don't present like a broken dist. belt.

TMc993

Thanks for the suggestions, but I don't think that the distributor belt is the problem...It was checked last month and was in good shape....Also, I'd think that if it was the belt, the symptoms would be constant, which they aren't.

Drove the car yesterday until the engine was warm, then parked it in the garage last night...No issues this morning...Starts quick and runs like a champ....I'm thinking the heat from yesterday's drive dried out whatever moisture was present.

I'm going to go ahead and do caps and rotors since they've never been done and hope that it isn't spark plug wires...I don't want to pay for wires and I sure as hell don't want the hassle of installing them.

BTW, just to get an idea of cost of wires I looked on Pelican's site last night...$500+...Is that accurate or are they smoking crack?

Thanks again,
T

Falcondrivr

You can get them for less from FD Motorsports. ~ $440, I think. I did the DIY kit where you re-use your old ends, and they were $189 from Sunset. However, it does take a couple of hours to disassemble, test, and reassemble the wires.
Good luck on the fix without wires. You should buy a lotto ticket if if works, just sayin'.
I would try the spray bottle at night thing to see if it's wires too. You can also look at the ones you can see closely. The exposed wires on the bottom banks behind the mufflers had visible cracking on mine.

TMc993

Thanks Rick...I'll definitely do a close visual inspection.

T

Augustus Davies

TMC,


Check your resonance flap actuator to make sure its working properly..clean your MAF sensor or buy a new one and it also could be a bad fuel pressure regulator..

And if replacing your wires don't solve your problem do a compression check.

So many times people think they have an electrical/fuel problem and it turns out to be a mechanical one......bad lifter or broken valve spring..

keep me posted..

MarinS4

I would start with plugs.

The breaking up is most likely the plugs not firing. Why is the big question. I have chased my tail on this one quite a bit on several 993's. It always came back to the plugs. Just because they are newish do not think they are good. Improper install, not gaping them properly (non OEM type) and not torqued (seen several loose). Its a good foundation to trouble shoot from as well.

TMc993

Thanks for all the suggestions....I will prioritize them and work though them...

I drove the car today (Ambient temp in mid-40s and very low humidity) and had no issues...Took a little extra time at lunch and made several near-redline runs through all gears....Ran strong with no issues.

Went by Auto Zone and put a reader on it...No fault codes thrown...

All of this non-information under dry conditions leads me to focus on the caps/rotors/wires/humidity scenario.

Of course this all occurred on the last day of a two week vacation and I'm now back at work so it will take some time for me to work through it.

I'll post again when I have something significant to report.

Again, thanks for the suggestions.

T

daveHy

Any progress Terry ? I have been following this thread as I have the same thing on my 96 ROW car. I have stuttering from 2-3k all the time which gets worse in the wet. Plugs / caps / rotors and wires all have less than 6k on them, belt is OK. I'm going for coils next. I may still have a dodgy wire or plug even though there near new. I run with the tray off which may not help in the wet. Will let you know if I make any progress.

dave hyde