85 442

[sldwys]

Stock car, check engine light is on. Got the codes to flash. But how the hell do you know what code it is.
I get the code 12 flashing. My error code seems to two quick flashes, followed by one.

Any clue?

 

[sldwys]

Would that be 21? Two quick followed by a single flash.

 

[69hurstolds]

21 IIRC is TPS signal high.

 

[L92 OLDS]

Trouble Code 21 indicates that the Throttle Position Sensor (TPS) is reading abnormally high. TPS volts should be close to 0.42 V at closed throttle and rise smoothly in about 0.02 volt increments to a maximum reading of about 4.85 volts at WOT.

 

[69hurstolds]

Make sure you're not seeing a code 12 instead of 21. I'm not doubting your flashing counts, but it goes in a series cycle, and code 12 will flash again when there's no other codes present. If you're not paying attention super close, it'll mess you up. I just let it run through a few cycles just to be sure. A 12 is normal. It means the ECM is communicating. This is a good thing. Any other code is your trouble area.

 

[69hurstolds]

ACDelco sensor p/n 17078448 if you can't adjust what you got.

Even found one for you for 23 bucks plus tax. All you got to do is buy it.

GM # 17078448 Throttle Position SENSOR | eBay

Part Grade Abbreviations. cc = Credit Card size units. C = Greater than 200k miles. B = Greater than 60k miles and less than or equal to 200k miles but greater than 15k miles per year. A = Less than or equal to 60k miles, or greater than 60k miles but less than or equal to 200k miles and less...

www.ebay.com

DON'T trust any other brand, if you want the sh*t to work right. If you can find an earlier piece that's not made in Pakmyassitan or some place like that. Not saying ACDelco is always the answer because sometimes the stupid sensors screw up or the newer junk is made in China and other idiotic places, but NEVER, and I mean NEVER run a Bosch sensor in your Olds 307.

 

[69hurstolds]

This can be helpful

 

[sldwys]

I made this video. Looks like it cycles through code 12, 3 times, then two quick flashes followed by the one.

 

[69hurstolds]

You got code 21 locked in. You MAY have an intermittent code. What I mean is, it got locked in, but may have gone away. Not always, but it's worth a shot. Unhook the battery for like 5 minutes or so. If you had a scan tool for OBD1 you could clear the codes immediately. Either way, clear the code. Then drive the car around awhile and see if it comes back.

It's the cheapest and easiest to do, and if it does come back, then you can start digging into your code 21 problem.

 

[69hurstolds]

TPS setting: approx. Between 0.41 [VIN Y] at min idle, (ISC retracted, A/C OFF), and 5.0 volts at WOT (<1 volt at idle, typically between 0.4-0.5 volts for Olds G-body 4 bbl). [VIN 9 is .046 @550 idle, A/C off]

1. Drill a 5/64" (0.078") hole about 1/16" to 1/8" deep in the aluminum plug covering the TPS adjustment screw. Be careful not to damage the adjustment screw.

2. Start a No. 8-1/2" long self-tapping screw into the plug enough to ensure good thread engagement.

3. Pry the plug out with a wide-blade screwdriver. Discard the plug.

4. Unplug the electrical connector at the TPS, then connect jumper wires between the three terminals of the connector and TPS.

5. Connect a digital voltmeter across the center and lower terminals: terminal "B" and terminal "C". Only a digital voltmeter with 10 megohm input impedance or higher can be used. Conventional voltmeters do not have sufficient resistance to obtain accurate readings.

6. With ignition switch ON, engine and A/C OFF, turn the TPS screw with tool j-28696 or BT 7967-A (or equivalent) to obtain the voltage specified in the carburetor charts. (Speical tool made for TPS hex headed adjustment screws) I think the hex driver tool size is 2.5 mm hex.

7. Turn off ignition. Remove jumper wires and voltmeter, and reconnect the TPS connector.

8. Install new tamper-resistant plug, until flush with boss. If not available, use silicon RTV sealant or equivalent.