Parts for your 1991 Suzuki Swift-Map sensor

1991 Suzuki Swift MAP sensor — what it does, where it is, and how to look after it

Yes, a MAP sensor is used on EFI-equipped 1991 Suzuki Swift models. Technical sources call it a “pressure sensor” and show it plumbed by a vacuum hose to the intake manifold. This is documented in the Suzuki Swift/Cultus Service Manual (1989–1993, Fuel and Emissions Control section), the 1991 Chevrolet/Geo Metro (Swift sibling) factory service manual under “Manifold Absolute Pressure (MAP) sensor,” and common Denso pressure sensor listings for G10 and G13 EFI engines used in that era. Note: base models sold with a carburettor in some markets won’t have a MAP sensor.

On a fuel-injected 1991 Swift, the MAP sensor is the ECU’s barometer for engine load. It reads manifold vacuum/pressure and helps the ECU juggle fuel and ignition so the little Suzuki runs crisply, sips petrol, and keeps emissions tidy. Most Aussie and Kiwi Swifts of this vintage have the MAP mounted on the firewall or inner guard under the bonnet, with a short vacuum hose to the throttle body or manifold. Some trims have it clipped to a bracket near the throttle body.

When the MAP sensor or its hose goes crook, owners often notice a rough idle, flat spots, sootier exhaust, or heavy fuel use. The check-engine light can pop on, and a quick paperclip code check (OBD‑I) will usually point you at the pressure/MAP circuit. Before blaming the sensor, always inspect the vacuum hose for splits, perishing, or oil contamination — a $5 hose can mimic a dead sensor.

Basic checks are easy with a multimeter and a hand vacuum pump. With ignition on, the MAP should show a steady 5 V reference, solid ground, and a signal that moves smoothly as vacuum is applied (roughly 1–4.5 V sweep). Any dead spots or no change usually means it’s time for a replacement.

Replacing the MAP on a Swift is a simple spanner job: disconnect the battery, unplug the connector, remove the screws or bracket, swap the unit, and refit the vacuum line snugly. If it uses a separate hose, cut a fresh piece of quality vacuum line to the correct inner diameter — don’t reuse a hardened one. After refitting, clear the ECU memory (pull the EFI fuse for a minute) and take it for a steady drive so the ECU relearns trims. As part of regular servicing, check the hose each 10,000–15,000 kilometres, confirm the connector is clean and tight, and make sure the sensor isn’t bathing in oil mist. Kept happy, the MAP helps the G10/G13 engines stay perky and economical for years.

• Technical sources referenced: Suzuki Swift/Cultus Service Manual (1989–1993, FI section: “Pressure/MAP Sensor”), 1991 Chevrolet/Geo Metro Factory Service Manual (Engine Controls: MAP), Denso pressure sensor cataloguing for G10/G13 EFI engines of the era.

Popular questions

Where is the MAP sensor on a 1991 Suzuki Swift?
On most EFI Swifts it’s mounted on the firewall or inner guard under the bonnet, connected to the intake by a small vacuum hose. Some models place it on a bracket near the throttle body. Follow the thin vacuum line from the manifold — it’ll lead you to the sensor with a 3‑pin plug.

Do carburetted 1991 Swifts have a MAP sensor?
No. Carburetted variants don’t use a MAP sensor because fuelling is handled mechanically. If there’s no ECU-controlled fuel injection and you can’t find a 3‑pin pressure sensor with a vacuum hose, yours is likely a carb model.

What are the signs a MAP sensor is failing?
Common symptoms include rough idle, hesitation on take-off, poor fuel economy, richer exhaust smell, and a check-engine light with a pressure/MAP-related fault code. Always check the vacuum hose and connector first — they’re frequent culprits.