QuestionQUESTION: Hi Todd
I wrote with on may 2 about car running rough while rev in idle. thanks for all your
help. it was one bad spark plug boot. have a question about the choke running slow.
noticed it for the last couple years. the cold choke only runs about 1/3 speed for about
1/3 as long as it use to. thought it might be in connection to coolant sensor. i
unplup sensor and check resistance in plug -not the coolant sensor. sensor checks
out o.k. for temp motor is. with key off im getting 0.0 volts . with key on and motor
off im getting 4.93 volts. question is that correct voltage for that plug and i thought yellow
wire was the hot wire. but its the black wire thats giving the juice . check by grounding
to block and side by side in connctor. same volt reading. I turn car on and fast choke a little
higher rpm. and coolant fan kick on after 2 minutes like i believe it should. is that the correct
voltage . And check battery while running ,it was charging at 14.38 v. volts. bounce down
to 12 a couple of times, Could'nt tell if that was me shaking or alternator. Read something
about regulator in alt can mess things up. Is all off that correct above. or to u see something
wrong that could keep the cold choke from running the rpms when it should. After car is warm
or hot and turn it off then turn it back on 5minute to half hour later, it will go to fast idle for about
7 secounds then drop back to normal idle. what do thank. just trying to get cold choke to run
right and everthing on car will be running great -for the milage that it has on it.
91 Sunbird LE 2.0L 115k miles .
Thank you Todd
Steve
ANSWER: Okay, The voltage is correct and the yellow wire is the signal return wire the coolant temp sensor runs off a 5 volt refrence so the 4.9 is close enough. This car doesn't have a choke. it has a idle air control motor If for some reason you messed with the idle stop screw with all the other issues you had youmore then likley induced the problem your self. You need a scan tool and look athe these readinf ECT IAT and IAC counts on a cold start the ECT and IAT should be within a few degrees of each other after the car has sat cold all night. Then after the car warms up you need to see what the idle are control counts are with the a/c off and the engine hot I would venture to say it should be between 10-20 counts with the A/C off. If it too high or too low you have to start looking for other factors that would change those #'s for the IAC like a TP sensor that is off at idle it should have approx .50 Volts if it to high or to low your back to the idel stop screw again.
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QUESTION: HI Todd
thanks for the input were to start looking. sorry for keep calling it a chock.i know its the iac sensor that lets more air when cold. but i still considerate the choke. lol question is all the big box auto stores around don't rent scanners. they will come out code read with a code reader if your engine light is on. but you have do buy scanners. which i cant afford. i have never messed with idle screw and the factory cap to is still on it. which i know i can punch out and can excess to. the only thing i ever done was to cheat it a little with a a small piece cut from a pop can which are like paper thin and folded it in half and silicone it to the -not the screw , but the other in that stops at the screw just to bring the rpms up 100 or 2 do idle smoother which i no is not the right way to do it but. would it hurt to move the idle screw and keep track of the turns on it going in or out to see how the motor reacts. so it may give me a ideal were to look if the high idle comes back if say i turn it in. i know its not proper way to do and i don't know anybody with a scanner.still goggling to look for a way to check tps and test with a ohm meter or probably should use a mechical one with needle for a better reading. since its in small .02 increments. but thats all i know about it and what prongs to test and how ,is still a mystery to me, there is -i think 4 wires to it so that makes it 4 prongs on tps. can u give me the procedure to test the prongs from rear to front on it. or do u know a web site that that shows it. i have saved and look at alot auto forems on net but can't find one. or do u think like the old saying is . if its working good, don't mess with!!!. and playing with the idle screw . would it hurt anything as long as i put it back were i exactly started at. thank u again Todd ..your awesome. p.s. just got to think outside the box when you have to..
Answertake out what ever yoiu put in the idls stop That will mess things up for sure Buy doing that you are making the idle conrol motor bottom out. the more you open the throttle plate the more the idle control motor will want to extend. if it keeps doing that it will wear the bore in the throttle body and the cone on the motor. What ever adjustment you make the engine computer will counter act it so stop playing around with the idle stop wether it's a shim or your you physically turn the screw. with out a scanner you can not tell what the idle control motor counts are. there is no volatge measurment you can make to tell where it is It's a bidirectinal motor and it doesn't have a position sensor. As for the TPS there are 3 wires on it I belive it's Blue, Black and grey. The black wire is the ground I would say and either the blue grey is the siganl return to the ECM test across the balck to blue and black to grey which ever one is NOT 5 Volts is the siganl return and that is your TP reading.
