As you probably know, the throttle position sensor (TPS) on your 1987-1991 2.0L Toyota Camry combines two sensors into one unit: the idle switch and the throttle position sensor.
The idle switch portion of the TPS lets the fuel injection computer know when the throttle plate is fully closed. This information helps the PCM manage the engine's idle more effectively.
In this guide, I'll walk you through testing the idle switch and adjusting the TPS assembly, whether the switch is out of alignment or you've recently replaced the sensor.
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles with automatic transaxle:
- 2.0L Toyota Camry: 1997, 1988, 1989, 1990, 1991
If you need to test the throttle position sensor part of the idle switch, this tutorial will help: How To Test The TPS (1987-1991 2.0L Toyota Camry).
TPS Adjustment Procedure w/ Manual Transaxle:
Idle Switch Continuity Tests
Testing the idle switch portion of the TPS is a straightforward process that involves checking the continuity between two specific terminals using a multimeter set to Ohms (Ω) mode.
Referring to the illustration of the TPS above, the terminals you'll need to identify and test are terminal #3 and terminal #4.
- Disconnect the TPS from its wiring harness.
- NOTE: This test is done with the engine OFF.
- Place the specified thickness feeler gauge between the throttle stop screw and the throttle lever. Use the table below to verify the correct continuity reading for this setup (for help locating the throttle stop screw, see: Location Of The Throttle Stop Screw).
If the continuity is not within specification, adjust or replace the TPS assembly as needed.
| Idle Switch Continuity Specifications | ||
|---|---|---|
| Feeler Gauge Thick. | Pins | Ohms |
| 0.020 In. (0.50 mm) | 1 and 2 | Continuity |
| 0.028 In. (0.70 mm) | 1 and 2 | No Continuity |
If the throttle switch on your 2.0L Toyota Camry doesn't pass any of the above pin continuity tests, then before replacing it, you need to make sure that it's not misadjusted. The next subheading will help you with this procedure.
Adjusting The Throttle Position Sensor Assembly
If you need to remove and replace the throttle position sensor assembly, you'll need to adjust it to the correct specification before you bolt it down.
This is a pretty easy adjustment and in this section, I'll show you how to do it.
This is what you'll need to do:
- Turn the ignition switch to its Off position and make sure the TP sensor assembly is disconnected from its connector.
- Place your multimeter in Ohms mode.
- Insert a.024 In. (0.60 mm) feeler gauge between the throttle stop screw and the throttle lever and:
- Test continuity between terminal #3 and #4. Your multimeter should register NO CONTINUITY.
- If continuity exits, adjust the TPS sensor by rotating it until the multimeter just looses continuity.
- Slightly tighten the TPS screws.
- Place a.020 In. (0.50 mm) feeler gauge between the throttle stop screw and the throttle lever and:
- Test continuity between terminal #3 and #4. Your multimeter should register continuity.
- If continuity does not exist, adjust the TPS sensor by rotating it until continuity exists.
- Slightly tighten the TPS screws.
- Place a.028 In. (0.70 mm) feeler gauge between the throttle stop screw and the throttle lever and:
- Test continuity between terminal #3 and #4. Your multimeter should register NO continuity.
- Repeat steps 3 and 5 to verify No Continuity and Continuity exist with the indicated feeler gauge thickness.
- Once the proper continuity specs have been verified, tighten the TP sensor assembly mounting bolts.
- Once you're done, recheck the continuities once more to make sure the TP sensor didn't move on you when you tightened the two bolts.
Location Of The Throttle Stop Screw
NOTE: To check and/or adjust the TPS assembly, you need to place a feeler gauge between the throttle stop screw and throttle lever. The orange arrow in the photo above points to this location.
The throttle stop screw is a small, adjustable screw on the throttle body of your 1987-1991 2.0L Toyota Camry. Its main function is to set the minimum position of the throttle plate when the gas pedal is fully released. This ensures a consistent idle by preventing the throttle plate from closing completely, which could cause the engine to stall.
When testing or adjusting the TPS, you'll need to create a precise gap between the throttle lever and the throttle stop screw. This is done by placing a feeler gauge between them. The gauge ensures the throttle plate is in the correct position for accurate TPS measurements or adjustments.
To help you locate the throttle stop screw on your Camry, refer to the image above. While the example shown is from a 2.0L Camry, the throttle stop screw on your 1987-1991 2.0L Camry will look similar and serve the same purpose.
Where To Buy The TPS And Save
Probably, the best place to save on the purchase of a new TPS, for your 2.0L Toyota Camry, is online. Check out the following links. I think they'll save you a few bucks:
Not sure if the above TPS fits your particular 2.0L Toyota Camry? Don't worry, once you get to the site they'll make sure it fits by asking you the specifics of your particular Nissan vehicle. If it doesn't fit, they'll find you the right one.
More 2.0L Toyota Camry Tutorials
You can find a complete list of 2.0L Toyota Camry tutorials and wiring diagrams in this index:
Here's a sample of the tutorials you'll find there:
- How To Test The TPS w/ Manual Transaxle (1987-1991 2.0L Toyota Camry).
- How To Test The TPS w/ Automatic Transaxle (1987-1991 2.0L Toyota Camry).
- How To Test For A Blown Head Gasket (1987-1991 2.0L Toyota Camry).
- How To Test The Engine Compression (1987-1991 2.0L Toyota Camry).
- How To Test The MAF Sensor (1987-1991 2.0L Toyota Camry).
If this info saved the day, buy me a beer!
