Menu toggle

K Reg 944 Idling / Low Rev Running Issues

Dave_Carnaffin

Dave_Carnaffin

PCGB Member
Member
I call upon the collective geniuses (geniui?) to help try and resolve an issue I'm having at present.

When the car is turned on (idling) or driving with low revs (regardless which gear) I'm getting a really rough driving experience. It almost feels like I'm running on soup (lumpy, struggling and refusing to pull). Once you manage to charm the engine to about 2800 - 3000 revs the car sets off like a scalded cat but still isn't perfect.

Tried (so far) by replacing dis cap, rotor arm, leads, swapped (borrowed) a different ECU and AFM.... initial results varied but then lapsed back to rough running.

Mechanically it seems fine ie no obvious parts fouling / broken. Had several sensors changed too but which these were I'm not 100% as they were carried out by Tom Ferguson of Gateshead.

Several people much smarter with engine matters than I have had a look (Mr Harm, Mr Chapman, Mr Poole & Mr Pollock) but we're still scratching our heads.

Any fresh ideas welcomed

Thanks in advance

Dave
 
Sorry that's just me not thinking whilst typing. Yes plugs were done when all the cap, rotor and leads were changed.
 
Hi Dave,
I'm no turbo expert, but as I understand things at low revs the turbo isn't doing much, so presumably the engine is relying on intake vacuum to pull the mixture in - have you checked all the rubber parts in the intake air tract (which is quite a lot of plumbing on a turbo) looking for air leaks?
HTH
 
Hi Dave,

Few questions:

how long have you had the car?
Has it been fine up to now ?
has anything been done recently before this happened ?

checking the vacume lines would be good idea as said. YouTube making a smoke tester which you can have smoke going through the vacume lines to detect a leak which will cause this. I would check it all over at all the bends for splits or cracks, especially check the line that goes under the throttle body.

not sure if you can maybe look it up in the Clarks manual online doing a multimeter check on the position sensors maybe just Incase it’s on it’s way out?

Is the timing spot on? Or few teeth out?

Check the intercooler pipes are tight and not loose, I’ve had mine stall on me whilst on the motorway and I thought my belt snapped and it would be fine once trying to start again, ended up being intercooler pipe comector loose and was popping off under load then going back into place in its own.

could also be a bad/ cracked leaking J-boot, this will show up with a smoke detectcror worth doing or pressurising should do the same?

just a few things I would check

good luck

Daniel
 
check and check again all vacuum lines, including hidden things like a bad diaphragm in the BOV and also the inter-cooler hoses...check FPR. Check your reference sensor multi-plugs are good, no corrosion. That's the easy stuff...assuming spark/fuel and compression is good I'd take a look at the cycling valve under the inlet manifold, check both the valve and the hose connections...these things get very brittle and either lose the plastic lugs that the hoses fit too or the wiring connectors. Also, the wiring/hoses in this area may be past their sell-by date, it's a very hostile environment under the inlet manifold, particularly on Turbos. Other easy things to check are the throttle position switch, you should be able to hear it click as the throttle is first opened (engine not running), also the idle control valve, this should also make a sound with the ignition is first switched on, again not turning the engine over, you'll need someone to help with this one, turning the ignition on while you listen to the ICV.

regards

Pete
 
digging up from dead !

just wondered if you ever got to the bottom of yr issue??

would be good to have a update if you can and see this ,..woukd personally love to know for knowledge and understanding of our cars and what can be the culprit ,…normally simple hidden things

arb
Daniel
 
Given he sold the car 2 or 3 years ago I think you’ll be waiting a long time for a reply Dan!
 
shame it got left incomplete , always sad when there’s no follow up as these things are so interesting to others
 
You must log in or register to reply here.

Posts made and opinions expressed are those of the individual forum members

Use of the Forum is subject to the Terms and Conditions

Disclaimer

The opinions expressed on this site are not necessarily those of the Club, who shall have no liability in respect of them or the accuracy of the content. The Club assumes no responsibility for any effects arising from errors or omissions.

Porsche Club Great Britain gives no warranties, guarantees or assurances and makes no representations or recommendations regarding any goods or services advertised on this site. It is the responsibility of visitors to satisfy themselves that goods and/or services supplied by any advertiser are bona fide and in no instance can the Porsche Club Great Britain be held responsible.

When responding to advertisements please ensure that you satisfy yourself of any applicable call charges on numbers not prefixed by usual "landline" STD Codes. Information can be obtained from the operator or the white pages. Before giving out ANY information regarding cars, or any other items for sale, please satisfy yourself that any potential purchaser is bona fide.

Directors of the Board of Porsche Club GB, Club Office Staff, Register Secretaries and Regional Organisers are often requested by Club members to provide information on matters connected with their cars and other matters referred to in the Club Rules. Such information, advice and assistance provided by such persons is given in good faith and is based on the personal experience and knowledge of the individual concerned.

Neither Porsche Club GB, nor any of the aforementioned, shall be under any liability in respect of any such information, advice or assistance given to members. Members are advised to consult qualified specialists for information, advice and assistance on matters connected with their cars at all times.

Porsche
Lockton
Pirelli
Officially approved
Oracle Finance
WEX Esso
Collecting Cars
Archant Dialogue
Back
Top