Parts for your 1991 Mitsubishi Pajero-Throttle position sensors

1991 Mitsubishi Pajero Throttle Position Sensor (TPS)

Technical sources confirm that a throttle position sensor is fitted to 1991 Mitsubishi Pajero models equipped with electronic fuel injection. The Mitsubishi Pajero/Montero Factory Service Manual (early 1990s editions, Engine Electrical section) details TPS testing and adjustment procedures for EFI variants, and the Mitsubishi ASA electronic parts catalogue lists TPS components for 6G72 3.0 V6 engines of this era. Broad aftermarket guides such as the Haynes Mitsubishi Montero/Pajero manual (1983–1993 coverage) also reference TPS diagnosis on EFI models. Carburetted petrol variants and fully mechanical diesel pumps of the same period may not use a conventional TPS, sometimes employing simple throttle switches instead, therefore, TPS relevance depends on the exact engine and fuel system.

On EFI-equipped 1991 Pajero models, the throttle position sensor plays a key role in how smoothly the big Mitsi gets about. Bolted to the throttle body, it reports throttle angle and rate-of-change to the engine control unit. That signal helps the ECU manage fuelling, ignition timing, idle control and, on autos, shift quality. Get the TPS right and the Pajero responds crisply, get it wrong and it can feel doughy off the line, surge, or drink more petrol than it should.

As part of routine servicing, owners are well served by giving the TPS and throttle body a once-over:

• Inspect the TPS connector and loom for cracked insulation, loose pins or greenish corrosion.
• Clean the throttle body so the blade doesn’t stick at closed throttle, which can skew TPS readings.
• Check base throttle stop and cable free play before touching sensor adjustment on slotted-mount units.
• Sweep-test the sensor with a multimeter for a smooth, steady change in output from closed to wide open, flat spots or jumps suggest replacement.

When replacement is needed, quality OEM or reputable aftermarket sensors make life easier. The job is straightforward: align the sensor tang with the throttle shaft, fit the screws lightly, then set the sensor so the ECU sees a correct closed-throttle signal before tightening. After refitting, clear any stored fault codes and allow the ECU to relearn idle (some models need a short idle learn procedure). There’s no fixed change interval, but checking the TPS every major service—or when chasing symptoms like hesitation, erratic idle, harsh shifts, or poor fuel economy—keeps the 1991 Pajero feeling sorted on Kiwi and Aussie roads.

Popular questions

How can someone tell if their 1991 Mitsubishi Pajero has a TPS?
EFI-equipped Pajeros—commonly the 3.0L 6G72 V6 and some injected four-cylinder variants—use a TPS mounted on the throttle body with a 3‑wire or 4‑wire plug. If the engine has a throttle body injector or multi-point injection and an ECU, it almost certainly has a TPS. Carburetted petrol engines and fully mechanical diesels may instead have simple throttle switches or none at all.

Checking the throttle body for a small black plastic sensor with a wiring plug is the quickest way. The factory service manual and parts catalogue for the specific engine code also confirm fitment.

What are common symptoms of a failing TPS on a 1991 Pajero?
Tell-tales include a stumble off idle, flat spots on light throttle, erratic or high idle, harsh or late shifts on autos, and higher fuel use. Some ECUs will log a fault code and trigger a warning lamp, but many early systems just run poorly without lighting a dash light.

If a throttle body clean and cable adjustment don’t help, a TPS sweep-test with a multimeter often reveals dead spots or noisy output.

Does a TPS need calibration after replacement?
Many Mitsubishi units are slotted for adjustment. After installation, setting the closed-throttle position so the ECU recognises idle is important. That typically involves a small rotational tweak before tightening the screws, followed by an idle learn procedure.

If the sensor is non-adjustable, ensure the throttle stop and cable are set correctly so the new sensor reads accurately at idle and at wide open throttle.