ISC testing Q?

[rconlon67]

Ok Quick Q...

following ISC testing procedure I found on this site, I check all 4 coils and they are in spec. Now I tried to apply 6VDC to the pins(plus side to 2-5 and negative to 3-6). I used 4 C batteris in series(+ to minus to plus to minus etc...) I measures the voltage @ 6.3V DC before applying it and I didnt get anythign out of the ISC...NOTHING.

My question is does anybody know if the 4 C Batteries will provide enough current to move the motor? or will the voltage drop so much that the motor will never buzz..

Thanks,
Ryan

 

[doggo]

decent charged batterys should work.

 

[rconlon67]

they were fresh out of the package....

 

[housegsx]

Test it by leaving it plugged into your car but unbolted so you can see it move when you turn the ignition.

 

[jdillen]

You need to come over and test my ISC motor too, kid.

 

[daren_p]

Test it by leaving it plugged into your car but unbolted so you can see it move when you turn the ignition.

If you do this, you should make sure to reset the ecu (ie unplug the battery) as the ecu doesn't get any feedback of where the actual ISC position is sitting. When the ecu is reset, it resets ths ISC back to its center position & then adjusts from there.

 

[luv2rallye]

^^^ Do what Daren_p says is easyest. But if you insist on using batteries, use the 4 C cells first to be safe (if this doesn't work then try 12V which is what the car uses). Also know that the ISC operates on pulses. A constant DC voltage could burn it out (especially with 12V). So just keep positive on pins 2 & 5 and then momentarily touch negative one at a time first to pins 4 & 6 and then to pins 1 & 3. You should feel a vibration if it's working on each touch.

 

[rconlon67]

I only wanted to use 6V because it specifically states in the haynes manual that 12V will ruin the motor. I did measure the voltage on the connector and noticed it was 12V and thought this was weird, but if its pulsing, I may not have picked that up on a digital multi- meter.....I am planning on trying to do the test the way darren_p mentioned tonight/tomnight.

On a side note, anyone have any tricks on getting the bottom screw/bolt out without taking the throttle body off? The top one came off no prob, but I can't fit the 8mm socket on the bottom on and can't get a screwdriver in between the block and the ISC properly...

Thanks for the input,
RyNo

 

[rconlon67]

ok guys,
tonight I was able to sucessfully get my ISC off the throttle body....let me tell you 1st that that lower bolt was a MAJOR PITA!!! I had to take the throttle body off, and use an 8mm open end wrench slid over top(kinda parallel as opposed to the normal perpendicular) and a set of vice grips to spin it...anyways..

I used the regular electrical connection, and turned key on and off, the motor moves in an out probly 1/8-1/4 in. is this the normal operation of the ISC?

thanks for any input,
Ryan

 

[doggo]

ok guys,
tonight I was able to sucessfully get my ISC off the throttle body....let me tell you 1st that that lower bolt was a MAJOR PITA!!!

thanks for any input,
Ryan

Yeah, it's common knowledge that ISC removal on a '90 is a PITA. Almost easier to take off the entire throttlebody first.

It's normal for it to move back and forth a small amount on ECU reset. This is the 'homing action'.