idle speed control motor problem (ISC)
can anyone help me with trouble shooting my ISC motor!!!
ive been having problems with my 1997 geo metro it would stall under hard deceleration and then it would start right back up . while finding many problems that i corrected like the egr replaced, short of a wire to ground in the harness, new cmp, changed coils, igniter, noise supressor, injector resistor, tps, map,ckp,isc, pcm ,vacum leak in the brakebooster line and loose hot and ground at the battery and loose ground at the tranny to battery . i added more ground jumpers all over the motor to firewall and battery just for kicks. what happens now is the if i remove one of the battery leads for a while and then put it back ,the car will start fine and idle great . once it gets warm it the isc motor starts raising and lowering the throttle and then shortly after that it will die. and not start. its getting gas ,20lbs pressure but no spark, the tps is set at 1volt dc with the thottle set up with a .14 feeler gauge. the ckp puts out .50vac and the cmp puts out .37 vac. vacuum reads 19. 14 before i changed the egr. the one thing that im having trouble testing is the idle contact in the isc motor. it shows a dry n.c. contact which is supposed to open when you give it gas. i put a continuity tester on the leads going to the contact and get no reading in any throttle position. thats why i replaced the isc. well the one from the wreckers did the same thing. so i went back to the wreckers and checked 5 that where there and i couldnt read thru any off them. so either im not properly testing them or there all bad. or the factory decided to save money and leave the contact outI(joke) please help, im loosing my mind . edit: i changed the statment about the contact to n.c. because there are differnt drawings that show it differnt and i think mines supposed to be normaly closed at idle. |
Welcome to the forum.:) I can't say I'm familiar with the 1997 Geo Metro (1.3L?) but are you talking about the idle switch at the ISC? If so, test the continuity across terminals 5 (BLK/BLU wire) and 6 (GRY/GRN wire)?
|
1 Attachment(s)
Originally Posted by EinST
(Post 177236)
Welcome to the forum.:) I can't say I'm familiar with the 1997 Geo Metro (1.3L?) but are you talking about the idle switch at the ISC? If so, test the continuity across terminals 5 (BLK/BLU wire) and 6 (GRY/GRN wire)?
|
Hmm, that's bizarre, unless you had the electrical connector in place and were just backprobing pins 5 and 6 through back of the connector in which case you aren't isolating the switch.
|
Originally Posted by EinST
(Post 177251)
Hmm, that's bizarre, unless you had the electrical connector in place and were just backprobing pins 5 and 6 through back of the connector in which case you aren't isolating the switch.
|
i got the wiring harness back together and hooked in some wire leads to term #5 and #6 of the isc. i connected the ends together to simulate a closed contact. it started right up but ran like crap! i thought omg wtf did i screw up in the harness! a check engine light came on #300, engine missfire(that narows it down lol) any way after almost commiting suicide i found i had knocked off the vacuum lead to the map sensor. whew!
i plugged it back in and it fired up and it idled great. i ran it at idle a while untill it warmed up and the isc motor stayed steady . now i wanted to simulate high speed so when i would open the throttle i would open the ends of the wires. it worked great and no stalling. so its got to be those contacts. well i hope it is . now to figure out why all the ones ive checked i cant get a reading. |
Note about this Idle Speed Control (ISC) on a 1997 Geo Metro 1.0L. It is a glorified AC idle solenoid. If it jams open, or surges, just unbolt it and reposition it out of reach of the throttle. Leave its electrical harness connected but remount it where it cannot reach the throttle lever. Then set up the idle manually with the idle set screw. Give it enough rpm to compensate for AC cycling. My AC has quit anyway.
|
Originally Posted by eshad
(Post 187439)
Note about this Idle Speed Control (ISC) on a 1997 Geo Metro 1.0L. It is a glorified AC idle solenoid. If it jams open, or surges, just unbolt it and reposition it out of reach of the throttle. Leave its electrical harness connected but remount it where it cannot reach the throttle lever. Then set up the idle manually with the idle set screw. Give it enough rpm to compensate for AC cycling. My AC has quit anyway.
|
im thinking that the problem was a shorting or malfunctioning injector. since when replacing the throttle body with its injector, tps,isc, heater, all at once its hard to pin down what part fixed it. i do show a code now for a bad cat, but it shouldnt be related
|
All times are GMT -5. The time now is 7:13 AM. |
© 2024 MH Sub I, LLC dba Internet Brands