the flyin' scotsman

yes............when the intake was off and when I had access to the Theo diag tool.

TPS good at idle and WFO electrical check............I didn't do the flappy brgs/seals as the valve works or the throttle valve.

Replace ALL is perhaps the moto with a +20Yo car.

Tails

Malcolm,

Have you pressure tested inlet maifold for leaks and checked all hose connections for tightness especially the inlet pipe securing jublee clips to IP valve.

Carry out a full adjustment of throttle cable, cruise control cable, AT box cable etc., etc., as per WSM.

Can you get Theo's Diagnostic tool again and CHECK ALL SYSTEMS for faults, check the operation of IP, throttle wide open and shut (do this a few time after giving the IP a good dose of WD40), check all the sensor readings especially the RPM at idle and compare it to rev counter , check that there is no faults with the speed sensor and then carry out an adaption set up and see what the results are.

Tails 1990 928 S4 Auto

worf928

Ok. So you tested the ISV with the Theo tool after the intake was back on. Yes?

Have you visually checked the throttle plate when it is at rest?

the flyin' scotsman

Dave...............the interval in time between the intake r&r and testing with Theos tool is approx. 2 yrs. I had Theos tool for testing on my car and a GT I'm working on but unfortunately there was a small issue and the tool was returned (currently lost in the mail between Canada and Holland ).

I drove the car again tonight............its perfect with exception of the high idle..........indicated in car at 1100rpm fully warmed up.

Actually, I'd profess, that the car has never ran as well with the latest new fuel pump and LH. I still do not know why my car died on the hwy and then restarted fine when flatbeded home. Living where I do I cannot afford it breaking down so I replaced the old FP and LH.

When I have Theos tool back I'll re-run all the tests and I have a co-op share on a STII so will tune the LH and EZK.

I recall that Sean recently found a cracked/broken plastic intake manifold hose diverter that caused a similar issue.

I'll live with the high idle until winter if all tests dont resolve the issue.............vroom

AO

I had someone ask me about a high idle today. Did you ever solve this?

SeanR

I think it was a busted ISV hose.

worf928

I believe that Malcolm diagnosed the culprit as a blown long hose (just replaced) to the ISV.

He's got a thread on it lying 'round here somewhere.

AO

Thanks guys. Will relay the info.