Porsche Enthusiasts Club Forum

Hi there.

My car has developed an intermittent stutter when cruising. It starts fine and runs fine apart from this odd intermittent stutter. It's not during acceleration but when running constant speed.

It won't be the fuel filter or fuel pump as they are brand new.

It's just had new spark plugs and the air filter is relatively new (under 18 months old).

Any ideas?

Thanks

Could be Air Flow Meter, sounds like it is running weak to me.

Looked at the internals of my AFM and the resistance tracks are pretty badly worn plus the circuit board is showing a bit of damp damage. I'll do the arm height readjustment over the weekend and see if that helps.

Don't really want to get a new AFM as my plan is to get the Augment ECU and MAF set up in due course.

No joy. Cars is now being irratic at idle too. Runs fine then occasionally drops revs.

All started after the blast down to simply Porsche.

I had that and changed the ignition module.

My stutter was at 2100 revs and it cured it

Hi

When were the dizzy cap/rotor arm last CHANGED ? not looked at but changed ?

All the best Brett

Bit reluctant to change the dizzy cap just for this. I had it off a while back and it all looked good.

The car does this at idle. I hear a faint click and the revs drop momentarily. The click noise is what is saying to me it isn't the dizzy.

Could it be a relay problem or a sensor?

mine did this on rare occasions which made it very difficult to trace. turned out to be fuel pressure reg. Got a used one for £25 to test it and it cured it straight away and five minutes to fit.
I'm putting the tester one on the bay for £25 soon..btw I think it was jmg on here saying how often they are the cause of poor running troubles. Meant to be changed every 60k and no-one does
Alex

The weird thing is is purrs like a kitten all the time except for this little blip every so often. I'm talking once or twice every 15 minutes. And there is this little click noise just as it happens. Sounds a bit like the DME relay is clicking off the fuel pump quickly and that causes the blip. I have a spare DME. I'll try twitching it over. The one on it is only 4 months old.

hmm,.. swapped the DME relay and went for a drive. Still doing it. Its weird as its so intermittent. It really runs well most of the time with no searching or erratic idle. It's now doing it every 30 seconds or so. Sounds like something is on its way out. Bugger

sorry to repeat myself but as I said..mine did this on rare occasions which made it very difficult to trace. turned out to be fuel pressure reg. not saying yours is but its very easy to change/check

I'm still having this problem.

Took it to the garage and had the throttle body cleaned and the injectors ASNU cleaned. It didn't solve the problem but the car does seem a little bit more spritely.

I think I will fit a new coil, distributer, rotor arm and HT leads and see if that helps. If that doesn't help I'll move onto the FPR.

The car runs fine other than at a low cruising rev when this stutter appears. I drove it down to Southampton and back a few weeks ago including a 2 hour crawl in traffic on the M25 and it was fine.

Infuriating.

I'm more familiar with turbo issues so not up to spec with N/A problems....where is this click coming from? have you checked all of the vac lines for any breaks...one item that does click (it's supposed too) is the idle control valve situated under the inlet manifold, these can fail but you said idle was fine so unlikely but always worth checking. You should be able to hear the valve click as you turn the ignition on, don't start the car as you're unlikely to hear it above the engine noise.

Pete

I did listen to the engine under the bonnet a while back it did sound like a phishing sound when the stutter happened.

I still have this annoying problem so I have got all the bits to replace the coil, HT leads, distributer, and rotor arm. The plugs are less than a year old so I'm not replacing them.

Anything I should be aware of replacing the distributor and rotor arm? Does the rotor arm have to be put on at exactly the same rotation or is it impossible to install wrong?

Obviously I need to make sure the HT leads are running to the same points and cylinder.

I have also obtained a new distributer gasket. This is missing from my car which is likely to be the cause of poor starting in damp weather after non use.

Thanks