mixmasterlex Posted March 25, 2009 Share Posted March 25, 2009 Yo, Mate has a silvertop in his ae101 sedan that he just put in. Running well but it won't idle below 1800rpm and just sort of surges. Have looked at a few things (ISCV etc) and think its because he has no air con and the air con plug on the loom is not connected to anything. We know which plug would normally connect to the aircon plump. What I wont to know is am I reading this diagram right? And if I bridge the two pins will that close the loop. Not 100% sure this is whats causing it but its worth a try. Picture below. Have circled the part I think I should be looking at. So I should bridge pins 9 and 12 on plug L? Has anyone had an issue like this before? I know its not oldschool but a few of you are running 4ages etc. Quote Link to comment Share on other sites More sharing options...
Spencer Posted March 25, 2009 Share Posted March 25, 2009 Hmmm trying to think back but pretty sure I left all my accillary idle ups with nothing on them. that diagram has a 12v rail with two diodes on both so looping them will do nothing, they go to ground when idle up is needed. It will idle up if theres fluctuations of the 12v signal on the +B wire but not likely. You sure the stepper motor is working correctly? I doubt it. Also you have to wire up the power for the ISCV switched off a relay from a ecu output so it can reset itself once the key is turned off (found that out by not reading a diagram properly) this can cause the idle to be fucked aswell as the ECU has no reference of position Quote Link to comment Share on other sites More sharing options...
mixmasterlex Posted March 25, 2009 Author Share Posted March 25, 2009 stepper motor. What does it do etc? Quote Link to comment Share on other sites More sharing options...
Spencer Posted March 25, 2009 Share Posted March 25, 2009 sorry stepper motor is the idle control valve, Quote Link to comment Share on other sites More sharing options...
mixmasterlex Posted March 25, 2009 Author Share Posted March 25, 2009 yeah he thinks it is. have already replaced it with another one that was rebuilt... But I dunnooooo Quote Link to comment Share on other sites More sharing options...
Spencer Posted March 25, 2009 Share Posted March 25, 2009 throttle stops wound all the way out? seen this on a few engines causing trouble, Also you need to check you've wired it up so its power feed is switched from the ecu so it resets when the engines turned off. Anyway step one should be to diagnose if it is the ISCV block the air feed to it and see if the idle drops. Then go about making sure it is wired and functions correctly. Also make sure none of the idle up input pins to the ECU are earthed etc etc Quote Link to comment Share on other sites More sharing options...
mixmasterlex Posted March 25, 2009 Author Share Posted March 25, 2009 throttle stops ok. cable has some slack in it. its running silvertop loom and ecu. When I take the air feed to the ISCV off when the car is running it stalls, If I put my finger over the pressure nozzle bit that feeds to the iscv I can limit the airflow to the point where the car is pretty much idleing normally... ISCV seems to have power going to it, i can blow through it when the car is switched off, and when the key is on and the car is warm I can't blow thorough it so it seems to be operating to some extent. I think most of the plugs are plugged in etc so not sure where it would be earthing but it's worth another look. Idle up stuff shouldn't cause the motor to rev this high and surge should it? Gah. Running outa ideas. really need to get his mechanic mate to take it into the workshop and plug it into the diag util. Quote Link to comment Share on other sites More sharing options...
NicT Posted March 26, 2009 Share Posted March 26, 2009 surging could point towards throttle position sensor or MAP, unplug these and see if it changes anything. Any vacuum leaks? High smooth idle would point to auxilliary triggers pulling it up, surging adds an unknown to the mix. Quote Link to comment Share on other sites More sharing options...
Spencer Posted March 26, 2009 Share Posted March 26, 2009 ^ yea for sure the surging is a worry those senders should pull codes (but not always). You can try this by shorting the TE1 and E1 pins in the diagnostics plug. Turn on the key and if engine light flashes constantly you have no codes quite quickly, longer varying flashes you can check up on the net what codes you have Quote Link to comment Share on other sites More sharing options...
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