4pin ISC how to test?

[chiuchimu]

I pulled out mt TB ready to test my ISC when I notice it has only 4pins. The only test methods i found were for 6pins types.

Does anyone know how to do this?

 

[boostforfun]

I am just asking because I have never seen a 4 pin IAC motor on a DSM. Are you sure you are not messing with the TPS? It has four prongs.

Included is a picture of the throttle body with the TPS and ISC detailed.

 

[chiuchimu]

No I know what a Tps looks like, Mine has 3pins.

 

[dannyd97gst]

IAC on non-turbo 2.0 is a 4 pin connector for sure. Measure resistance on the pins of the connector 1 and four, should be between 38-52 ohms at room temp (68 degrees F)

 

[Lofty]

He has a 420A motor....
The 6 pin are for the 2.0S and the 2.0S only.

I DOUBT it's your ISC motor, the 420as rarely if ever have idle problems. Check elsewhere for your problems. If you have any...

 

[dannyd97gst]

Pretty sure the 420a is speed density and most likely will not experience idle issues with vacuum leaks unless very large, they are much less sensitive that the 4g63. I've seen the 420a's run fine with the brake booster hose off sucking air.

 

[dannyd97gst]

I ignored the obvious. Why are you testing the iac/isc

 

[Lofty]

Pretty sure the 420a is speed density and most likely will not experience idle issues with vacuum leaks unless very large, they are much less sensitive that the 4g63. I've seen the 420a's run fine with the brake booster hose off sucking air.

Ah, Good to know. Well not really. It's a 420A
I'm just trying to prod information as to WHY he's even testing it in the first place.

 

[stevo911]

Not sure about checking resistance mayb you can do the other test? Unhook it from the throttle body turn the key over and make sure it goes in and out smoothly.

 

[chiuchimu]

Thanks for the responses

I'll check across 1 and 4 to see if its about 30 -50 ohms

My problem is weird.

slightly high Idle: in drive 900rpm in park 1100rpm

1) lift off the brake, car sits there or goes forward a little, like normal.

2) press gas pedal slowly, car starts forward normally.

3) take the foot OFF gas, Now instead of slowing down, it keeps going like the cruise control is set. it seems to want to slowly accelerate to 1400-1500rpms then cruise at the rpm(about 40mph). My foot is completely off the gas pedal. On the freeway driving 70mph, if i take the foot of the gas, it will slow down but no lower than 40mph.

4) I press the break pedal, the car starts to slow down, rpms drop. There is a little hiccup like thing(rpm dips down then up then steady -I would not describe it as a surge) then it steadies at 900rpm. As long as I'm stopped, the rpms will always drop to 900. The engine is not fighting the brakes, its like the brake sent a signal and triggered an engine deceleration.


So, from a driving point of view, releasing the gas pedal doesn't slow down the car, only by touching the brake pedal will the car slow down.. It does this all day long, every stop, every time i press the gas. Hot cold doesn't matter. And the engine is runny perfect,very smooth.

I'm thinking one possiblility is a Vacuum leak behind the engine, I check the front and, I couldn't really get back there to check the back area.( My method is to spray carb cleaner at hoses and gaskets and listen for a change in engine sound.)

I wanted to check the basics first egr, tps, isc, o2, etc.. before I ripped my car apart.

 

[sarge281]

Oh hell, I'll be the test-dummy and ask this question: could it be the vehicle speed sensor? My cruise control just quit working one day, and I replaced the dash-switch...it wasn't that. I asked a trusted source @ my Mitsu dealership, and he told me to replace the vehicle speed sensor (I think that was the name of it). I haven't done it yet, but I thought I would just throw it out there.

 

[boostforfun]

It sounds like a vacuum leak or sticking TB butterfly to me.

Sorry about the stupid post earlier, It never entered into my mind that it could be a 420a. With some of the questions that are on here, i thought i better make sure.

 

[stevo911]

Did you happen to adjust the throttle cable before all this started?

 

[chiuchimu]

The throttle cable has slack.

Just received my used ISC and TPS from Ebay so i'll test those tomorrow .

Still waiting on O2 sensors.