Docile 64 Report post Posted May 20, 2014 Ok im stumped on this one, my car is now idling too high after 2 months storage in the garage. first start up idle was at about 1,100rpm. engine got up to normal temp and idle still the same. no rough idle or lose of power after a 15 minute spirted drive. i took out the idle control valve and cleaned it and clean the contacts as well. put it back in still the same. while idling, i unplugged the idle control valve and idle went down. borrowed my friend's idle control valve from his m60 (working fine), plugged it in and still the same. but now idle is around 1,200rpm. unplugging it while idling it goes down to 1,000rpm. im stumped on this one. previous job done the the car was when my dad replaced the thermostat housing. ive checked all the sensor plugs are in and all hose clamps are tight. Could it be a vacuum leak somewhere? or stale gas? i only hear noticeable intake noise from the air filter side and at the intake manifold. Quote Share this post Link to post Share on other sites
B.M.W Ltd 950 Report post Posted May 20, 2014 Will need to be scanned first and work from there Quote Share this post Link to post Share on other sites
Docile 64 Report post Posted May 20, 2014 alright will check the TPS. found some info on how to test it. will update later. Quote Share this post Link to post Share on other sites
hybrid 1039 Report post Posted May 21, 2014 Scan won't necessarily expose the fault but it's a reasonable suggestion. Based on personal experience, test the Throttle Position Sensor. You can do that for free with a multimeter. I'd recommend that before a code scan. That or measure the real time data of each related component. However this requires knowing what expected ranges are from each sensor at given a load/time/operation. The TPS is only a digital representation of a mecahnical action. It is an adapted value as in the DME will read the voltage on key position 2 first start and treat that value as 0% throttle. Quote Share this post Link to post Share on other sites
Docile 64 Report post Posted May 21, 2014 (edited) alright so did some tests on it. there are 2 of the same sensors. the 1st one is before the throttle body on the 'L' bend into the throttle body. saw the same part number so tested it first. on the first TPS? (looks like a throttle body valve as well) opening and closing the valve the ohms went up and down within the specified range of approx 1ohms - 4ohms. tested the one on the throttle body, the ohms barely moved as i opened and closed the throttle cable. will update on this when i get to take it out and replace it with my friend's working one. Edited May 21, 2014 by Docile Quote Share this post Link to post Share on other sites
BM WORLD 1264 Report post Posted May 21, 2014 alright so did some tests on it. there are 2 of the same sensors. the 1st one is before the throttle body on the 'L' bend into the throttle body. saw the same part number so tested it first. on the first TPS? (looks like a throttle body valve as well) opening and closing the valve the ohms went up and down within the specified range of approx 1ohms - 4ohms. tested the one on the throttle body, the ohms barely moved as i opened and closed the throttle cable. will update on this when i get to take it out and replace it with my friend's working one. the 1st one after the airbox is for the traction control valve to shut off the intake pipe when you break into a power skid Quote Share this post Link to post Share on other sites
Docile 64 Report post Posted May 28, 2014 (edited) Ok Update: replaced the TPS sensor with a known working one and also replaced back and forth the idle control valve. still nothing. the ICV is working (humming from the motor could be heard) but will check tomorrow if the valve insie it opens and closes forgot to check it. still idling constantly on about 1500rpm. car drives great no power lose, only thing i noticed was braking was a bit harder than usual with engine idling high. car starts fine at first tick no problems. on Drive, car idles at about 1k. had the car scanned and no errors showed up. ECU read out says no error transmission read out no error i tried removing the ICV when the engine was idling, it dropped down to 1k. plugged it back in, it went back to 1500rpm after about 10 - 15 secs. looks like i will be hunting down vacuum hoses for leaks. anyone have a diagram or know which ones could be the culprit. thanks Edited May 28, 2014 by Docile Quote Share this post Link to post Share on other sites
Docile 64 Report post Posted May 31, 2014 (edited) MHAHAH!!.. fixed the bugger. so my friend and I just said F it. went to super cheap got 2 cans of throttle body cleaner, a can of maf cleaner, 2 cans of degreaser, then bought intake manifold gaskets, throttle body gasket, paper towels, rags and a very cold Saturday morning till early afternoon + burger fuel combos dont know which one had the air leak but now its purring like new again Edited May 31, 2014 by Docile Quote Share this post Link to post Share on other sites
