throttle boddy clicking!!!! help!!!

AKPsiMC03 · #1 (**permalink**) 03-27-03, 11:34 PM

I got home from school tonight and i turned off my car. I heard a clicking noise so i opened the hood. Now the key was all the way off and i had them in my hand, but the throttle body was clicking open and closed!!! It does this too when i turn the ignition on but dont start it. I think its what is causing my surging when i drive.

someone please help me fix this. I ran the code scan on the DIC tonight and no codes only "history A037" whats that one?

but this throttle body opening and closing thing is getting on my nerve... oh yeah, it is moving on the cruise control cable, not the accelerator cable.

please help me!

Katshot · #2 (**permalink**) 03-28-03, 05:05 PM

That's a loss of IPC seria communication. Did you have the instrument cluster worked on? That's usually what that code's from.
As for the TB opening and closing by itself, that's a new one on me, sorry.

AKPsiMC03 · #3 (**permalink**) 03-28-03, 05:45 PM

i havent had it worked on... and the throttle body opening and closing... its not any cable pulling on it cus there is slack in both cables when it does it. Is the throttle plate motorized to work with an idle air control valve? Im pretty sure that is whats causing my car to surge at lower speeds.

eehoepp · #4 (**permalink**) 04-23-03, 10:46 AM

My 94 STS started doing this same thing.

It's the Idle Speed Control motor that's popping the throttle plate open and closed. I also believe this is what causes the surging. At one point it was "idling" at 3000RPM. Kind of tough to brake to a halt when the engine wants to go.

Have you found a fix yet?

I pulled code P027 History, which is " Open Throttle Position Switch Circuit". As far as I can tell from the service manual, the TP switch is built into the Idle Speed Control motor (this is not the throttle position sensor). The service manual (right now it's at home & I'm at work) also says that if you are in the PCM diagnostic mode, the climate control "LO" indicator shows the state of this switch. If the gas pedal is released, "LO" should show. If you press the gas pedal, "LO" should go off. If the pedal and "LO" indicator are out of sync, the car either has a wiring problem or a bad ISC motor.

I'm going to dig deeper into it tonight.

Katshot · #5 (**permalink**) 04-23-03, 11:19 AM

To be honest, I had forgotten that early Northstars used a ISC.
They are definately a PITA. They are a left-over from the old DFI engines and do tend to cause problems. The TP "switch" is in the ISC, and basically just tells the computer that the throttle is closed and that IT should now control the idle. The TP "sensor" is mounted on the end of the throttle shaft. The TP switch can be tested with an OHM meter. The ISC has 4 contacts in the connector, the A&B contacts are for the TP switch, and the C&D contacts are for the ISC motor. The switch contacts will show an open and close circuit when the plunger of the ISC is depressed and released. You should also feel a slight clicking (it's just a little micro switch). The motor circuit can be tested with test leads, battery, and ground. The motor is reversed via reversing the polarity. FYI; the motor is the same motor used on Kodak slide projectors to move the lens in and out.
The status light you're talking about is just an indication of what position the TP switch is in.

eehoepp · #6 (**permalink**) 04-24-03, 02:09 AM

And as abruptly as the ISC motor started clicking and fidgeting around... it stopped.

Hmmmmm...

I cleared the P027 History code & waited to see if it would return. It didn't. I find this bizarre, but I'm not complaining. At least I'm forearmed if it comes back.

AKPsiMC03 · #7 (**permalink**) 04-24-03, 04:32 PM

what did you do to figet around with it? mine onlty does it ocasionally.... it stopped compleetly for a while after i replaced the front O2 sesor that went bad. the rear still needs to be replaced. But my best guess was that the ISC was chasing a rich condition and trying to compensate for it, even after the car was turned off.

Katshot · #8 (**permalink**) 04-24-03, 05:14 PM

Unlikely. The ISC "should" open the throttle slightly after the engine shuts down.

BlownC5 · #9 (**permalink**) 05-10-03, 05:31 PM

Mine is doing the same thing. Anyone know a fix for this? Thanks

eehoepp · #10 (**permalink**) 05-18-03, 02:00 AM

I forgot to include something in my previous post. The ISC pushes on the throttle with a hex-head screw. I tightened that screw into the ISC until it bottomed (FWIW, it was 20 times one sixth of a turn if I ever have to put it back). I knew it wasn't the best way to deal with it, but I needed to get home from work (20 miles) and the 3000RPM surge in traffic was risky.

It still surged a bit on the drive home & it still clicked after I shut it off that night. But after that, it stopped. To me, it almost seemed like it was trying to re-calibrate itself, but I have no idea if the PCM is capable of doing that. I haven't had a problem with it since.

I don't think this is "the" fix, but it seems to have worked for me.