Porsche Enthusiasts Club Forum
https://forums.tipec.net/

Stutter at speed
https://forums.tipec.net/viewtopic.php?f=25&t=19965		 Page 1 of 2
Author:  Bow Runner [ Mon Jun 08, 2015 11:53 am ]
Post subject:  Stutter at speed
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
Author:  tr7v8 [ Mon Jun 08, 2015 12:04 pm ]
Post subject:  Re: Stutter at speed
Could be Air Flow Meter, sounds like it is running weak to me.
Author:  Bow Runner [ Thu Jun 11, 2015 8:37 am ]
Post subject:  Re: Stutter at speed
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.
Author:  Bow Runner [ Sun Jun 14, 2015 6:32 am ]
Post subject:  Re: Stutter at speed
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.
Author:  Gary Howard [ Sun Jun 14, 2015 9:47 am ]
Post subject:  Re: Stutter at speed
I had that and changed the ignition module.

My stutter was at 2100 revs and it cured it
Author:  Brett928S2 [ Sun Jun 14, 2015 10:19 am ]
Post subject:  Re: Stutter at speed
Hi :)

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

All the best Brett :)
Author:  Bow Runner [ Sun Aug 09, 2015 7:04 pm ]
Post subject:  Re: Stutter at speed
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?
Author:  alexsmith [ Mon Aug 10, 2015 3:23 pm ]
Post subject:  Re: Stutter at speed
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
Author:  Bow Runner [ Mon Aug 10, 2015 10:15 pm ]
Post subject:  Re: Stutter at speed
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.
Author:  Bow Runner [ Tue Aug 18, 2015 7:58 pm ]
Post subject:  Re: Stutter at speed
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
Author:  alexsmith [ Wed Aug 19, 2015 12:52 pm ]
Post subject:  Re: Stutter at speed
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
Author:  Bow Runner [ Sun Nov 22, 2015 11:54 am ]
Post subject:  Re: Stutter at speed
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.
Author:  PSH [ Sun Nov 22, 2015 12:52 pm ]
Post subject:  Re: Stutter at speed
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
Author:  Bow Runner [ Sun Nov 22, 2015 4:50 pm ]
Post subject:  Re: Stutter at speed
I did listen to the engine under the bonnet a while back it did sound like a phishing sound when the stutter happened.
Author:  Bow Runner [ Thu Jan 07, 2016 1:19 pm ]
Post subject:  Re: Stutter at speed
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
Page 1 of 2 All times are UTC
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/