Mrmerlin

do you have ISV plugged in, its hard to do??
did you use new hoses on the ISV.
check at the fronts of the intake where it sits next to the water bridge sometime the intake edge flange will hit on the water bridge and leave a space between the gasket and head, pulling a the plugs will also add info the running. Did you replace the plastic connectors that plug into the sides of the MAF boot?

NOTE 4 different cables
Is the throttle cable fully released?
is the quadrant to throttle plate housing fully released, does the TPS click when released?
Is the Bowden cable fully released
Is the Cruise control cable fully released?
Please post a picture of the throttle quadrant with the cables installed

the flyin' scotsman

I knew he is Welsh and saw your location hence the mention.........you need to clone him and Ryan Giggs a few times over

Given that the idle issue hasn't changed since all the work performed on the intake and the you cant detect a leak when pressured perhaps we should look at the electrical side of idle control.

I suggested previously using a spanner or another diag tool to connect through the diag port to check many parameters including the LH, injectors and ISV. With Johns generous offer to borrow a spanner thats the route I'd now take.

There will be a delay in responses over the next few hours............big F1 fan so will be glued to the plasma idiot box watching the race from Brazil

stevedavies

Mrmerlin, yes ISV is connected, it was a pain to get to so I attached it to throttle body first then attached body to intake, difficult to do but easier than trying to connect the plug to ISV.
yes changed all hoses underintake, inc ISV, TPS, flappy valve and bearings. I dindnt want to back in there hence replaced everything.
Ok will check intake to water bridge, will have to be am, but pretty sure ok as there is no sign of leak ( used smoke matches)

Also changed plastic connectors and MAF air cowl. I will post picture of throttle cables tomorrow, but pretty sure its ok. They are loose. Pulling throttle cable slightly then I can hear the TPS clicking. I verified this at the LH and EKZ ECU's in car.

stevedavies

John, you mentioned the idea the control loop was not working....a thought ..the idle when stone cold is approx 800 rising to 1100rpm when warm. Increase to 1100rpm is linear and takes approx 5 to 10 mins ( mirrors the temp gauge). When both cold and hot the idle is steady and I can hear it gently hunting, both cold and hot temperatures. Would you expect the hunting to be present when engine cold?

stevedavies

Mrmerlin, have attached pic of throttle quadrant. Rechecked and none of the cables are under tension. I can also hear the TPS clicking by applying slight opening of throttle.
Also checked the intake to water bridge, intake is sitting properly on engine, not fouling bridge.
I will have loan of spanner this week so hope that will shed some light on the problem!

Cosmo Kramer

Have you checked the idle switch at the LH and EZK plugs inside the car with a multimeter? At 0 throttle it should be 0 ohms to ground. I had a connector fail and caused a high warm idle, but I could still hear the switch clicking.

stevedavies

Yes checked idle and WOT at both LH and EKZ ECU's. Prior to refresh I knew the TPS was open circuit at all throttle settings. After replacing TPS as part of the refresh, idle behaves the same ie 1100rpm when engine warm. Its like the idle is independant of the TPS

AO

I haven't reat all 60+ posts on this thread, but generally speaking, a high idle is often cause by a false air leak after teh MAF. If you have access to an air comperssor, the fastest way to check this is to get a PVC end-cap that is the same diameter as the MAF. Mine was slightly larger and I used my router table to take down a little bit around ther circumfrence. Then tap the end cap to accept a quick connect air fitting. Install in place of the MAF, and pressurize to about 10psi. You'll find your false air leak in seconds. BTW, this works great for the SC/Turbo guys too.

stevedavies

Andrew, I tried pressuring intake ( used Dwaynes idea from his intake refresh write up) with air compressor. Only took it to approx 2.5psi and it took approx minute to decay to zero. There was nothing evident. Tried smoke matches too. Am getting approx 20in HG at front fuel damper

the flyin' scotsman

Did you try the spanner or another diag system yet?

Interested to see whta fault(s) show up.

John Speake

It's on it way to him..... he will have it Wednesday.

stevedavies

Malcolm, yes John has kindly sent me a 'spanner'. Should be with me tomorrow, will give an update tomorrow on results.

stevedavies

Malcolm, tried the 'spanner' today on car, all checked out good, ECU's, actuators etc. Tried the idle stabilisation routine but didnt seem to make any difference to idle. John is loaning me another LH to try. I guess this is a long shot as it tested ok on bench with John. I tried re pressurising intake agian today. Took it to 10PSI. Held pressure for some time, heard it escaping through dipsstick ( i loosened it and it shot into my hand), also very small leak at oil filler cap. Remaeasured vacuum with hot engine and was 19in HG.
Am getting the FOR SALE sign ready now!!!

stevedavies

Drove the car to work today ( 10miles). At the end of the journey the idle was 900rpm. Its never done this before, always been consistently 1100rpm. Only thing I can put it down to is the idle adaption routine I tried yesterday using the 'spanner' (thanks again John). Will check again this evening and see how it performs.

John Speake

Suggest you drive it at least another 25 miles to make sure that O2 adaptation is complete. This is seperate to idle adaptation, but they are interdependant.

Porsche reckon it can take up to 50 miles to fully adapt O2 loop.