993 fast erratic idle problem
Discussion
My 993 (Varioram) has recently decided it no longer wants to idle at a steady 800rpm or thereabouts and will only alternate between 1200 & 2000rpm constantly, making it look like I'm sat there at the traffic lights revving like some sort of attention seeking boy racer.
After searching on here, I found some threads about the Idle Control Valve so I took it off, found it to be filthy and not moving freely like it should so I've given it a clean and put it all back together and disconnected the battery for half an hour then let the car idle for 10 minutes (much to the annoyance of the neighbours I'll bet) to reset the ECU but without success.
Is there anything else I can try before taking it to a specialist?
If it makes any difference, it has been in storage for the past 4 years but warmed up regularly and driven about but only on a driveway and hadn't had any problems for the past few journeys since I put it back on the road about a month ago.
I've also put £90 of petrol in on top of the old stuff which wasn't much. Under normal driving i.e. with the throttle open it's fine.
After searching on here, I found some threads about the Idle Control Valve so I took it off, found it to be filthy and not moving freely like it should so I've given it a clean and put it all back together and disconnected the battery for half an hour then let the car idle for 10 minutes (much to the annoyance of the neighbours I'll bet) to reset the ECU but without success.
Is there anything else I can try before taking it to a specialist?
If it makes any difference, it has been in storage for the past 4 years but warmed up regularly and driven about but only on a driveway and hadn't had any problems for the past few journeys since I put it back on the road about a month ago.
I've also put £90 of petrol in on top of the old stuff which wasn't much. Under normal driving i.e. with the throttle open it's fine.
Drive the car. It needs to be driven. Drive it.
I'm sure you'll spend a great deal of money replacing sensors and vacuum pipes, but why bother if it sits in a garage?
But if you are going to spend a few hundred pounds chasing a problem that is due to lack of use, I'd book a slot with Wayne and do the job properly.
I'm sure you'll spend a great deal of money replacing sensors and vacuum pipes, but why bother if it sits in a garage?
But if you are going to spend a few hundred pounds chasing a problem that is due to lack of use, I'd book a slot with Wayne and do the job properly.
Orangecurry said:
ps what did you clean the ICV with? It needs carb-cleaner, and ideally sit it in a ice-cream-tub of the stuff overnight.
Eat the ice-cream first.
I soaked it overnight in an ice cream tub of white spirit as per some of the recommendations on here then cleaned it up with cotton buds & kitchen roll. The valve went from not moving to rattling around like a big heavy baby's rattle. I was kind of hoping that would do the trick. Eat the ice-cream first.

neilski said:
I soaked it overnight in an ice cream tub of white spirit as per some of the recommendations on here then cleaned it up with cotton buds & kitchen roll. The valve went from not moving to rattling around like a big heavy baby's rattle. I was kind of hoping that would do the trick. 
It should display a kind of springyness to it IIRC - a sort of weighted inertia.... something like that anyway.
If you are now back for a while, seriously I'd take it to Wayne. He'll sort any issues out as part of the remap.
But for now - warm it up, and then thrash it senseless, three times a day.
mollytherocker said:
Have you given it a proper Italian tune up? i.e; a damn good thrashing!
And not just for 20 minutes, a proper work out!
Yes on Sunday but not since I cleaned the ISV. It was a bit of a PITA at each traffic light & junction so when the problem hadn't gone away I wasn't in any rush to drive it again today. I'll try it again tomorrow and report back.And not just for 20 minutes, a proper work out!
neilski said:
Orangecurry said:
I'm sure you'll spend a great deal of money replacing sensors and vacuum pipes, but why bother if it sits in a garage?
It's been in a garage because I was off cycling around the world but I'm back now so was hoping to start using it again, problems permitting!Legend!!!


Sorry, back on topic.....
That is Goodwood and I've been lots of times over the years as my parents live in West Sussex so I'll go to various car events with my dad.
Top stalking about my birthday. Where did you see that? If I view my Facebook profile in public mode nothing comes up and I can't think of where else it would be.
Top stalking about my birthday. Where did you see that? If I view my Facebook profile in public mode nothing comes up and I can't think of where else it would be.
Well the Italian tune up (including through Petworth) didn't cure the problem so does anyone have any other ideas before I part with money I haven't got at a specialist?
The car feels fine on the throttle but very jerky if I lift off or when I go back on to the throttle from overrun, and still likes to do it's boy racer impression at junctions. The revving is very uniform and consistent though as opposed to completely random and erratic.
Also, does anyone have any recommendations for an indy close to Horsham?
Or does anyone want to buy a lovely midnight blue 993 C4 with only 88k on the clock?
The car feels fine on the throttle but very jerky if I lift off or when I go back on to the throttle from overrun, and still likes to do it's boy racer impression at junctions. The revving is very uniform and consistent though as opposed to completely random and erratic.
Also, does anyone have any recommendations for an indy close to Horsham?
Or does anyone want to buy a lovely midnight blue 993 C4 with only 88k on the clock?

You did it this afternoon? Dang we could have done a convoy down that road (one of my favorites if you add in Wisborough Green).
GCS at Mannings Heath certainly know how to set up the GEO on a 993, but chasing an idle problem could involve a long list of trial and error, the length of which wouldn't necessarily be the Indie's fault.
There are a few others in Horsham itself that I might not use, because of various things I've heard, but it is all 2nd or 3rd hand info.
Book it in for a remap with Wayne Schofield at Chip Wizards - it's a win-win as the car will be transformed.
GCS at Mannings Heath certainly know how to set up the GEO on a 993, but chasing an idle problem could involve a long list of trial and error, the length of which wouldn't necessarily be the Indie's fault.
There are a few others in Horsham itself that I might not use, because of various things I've heard, but it is all 2nd or 3rd hand info.
Book it in for a remap with Wayne Schofield at Chip Wizards - it's a win-win as the car will be transformed.
Edited by Orangecurry on Thursday 14th January 16:17
davek_964 said:
I already posted what worked for me on a 964, and it wouldn't be an expensive thing to try.
The whole dual dizzy thing and connecting belt might well need replacing, but it isn't cheap.... especially if it isn't the cause.Ask on Rennlist as they are usually very good at detailing easy things to check, but at the end of the day.... Wayne
Orangecurry said:
davek_964 said:
I already posted what worked for me on a 964, and it wouldn't be an expensive thing to try.
The whole dual dizzy thing and connecting belt might well need replacing, but it isn't cheap.... especially if it isn't the cause.Ask on Rennlist as they are usually very good at detailing easy things to check, but at the end of the day.... Wayne
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