hey guys just finished an engine swap on my manual ef xr6 to a stock ef 6 engine and now revs stick at 2-3000rpm during gear changes and any time clutch depressed also revs slow to drop when free reved, had the issue at times before engine swap but now all the time. have repaired all vacum leaks replaced isc valve, tested tps, neutral switch and set base idle correctly can anyone help have run out of ideas and struggling to find info

Clean out throttle body and lubricate throttle shaft.Also check for frayed/sticking accelerator cable or sticking accelerator pedal.When you say base idle was set correctly,was it set to between 680-720rpm(use a digital tachometer,hooked up to tachometer output in diagnostic connector,do not rely on the one in instrument cluster as not accurate enough) in diagnostic mode?If throttle stop screw is turned in too far,it will cause what you describe(I know this as I own a factory manual EF XR6 and have actually experienced this).May also be caused by a sticking idle speed control solenoid,broken isc solenoid gasket or faulty ECU,especially the idle circuit.

Did you reset the ecu after setting base idle?

If not, just pull the 'ENG' fuse for 30 mins and see if it improves.

Simple solution.. p!ss the ISC off like i have, no more rev hang or anything. Improved drivability 100%, just gotta disconnect it, and wind the idle screw in till it idles at the rpm your happy with,

The ONLY downside with this is.. when its cold in the mornings you have to hold your foot on the accellerator at 750odd rpm for 20-30odd seconds till shes happy to idle itself, but other than that small issue which doesnt bother me its 100% better. No fluctuating in idle or anything like it was with the ISC.

My two cents worth.

Thanks for the info guys but already fixed it put my throttle body from my engine on it and now all good had a look at the other one and found excessive air gap on left side of butterfly letting air in causing the high revs. Zabatron are you sure those base idle specs are right they sound more like idle not base idle my book says 450 to 600 for base with normal idle 750 +|- 50 for manual

Just checked base idle specs in Ef Falcon factory workshop manual and the Gregorys manual,and for 6 cylinder engine they both clearly state base idle of 700rpm-plus or minus 20rpm..thus 680-720rpm.Factory manual also has base idle specs for v8 which is 580rpm-plus or minus 20rpm..thus 560-600rpm for the V8.Anyway,glad to hear you found the problem.