Parts for your 1991 Suzuki Jimny-Map sensor

1991 Suzuki Jimny MAP sensor — is it there or not?

For Australian and New Zealand–delivered 1991 models (sold locally as the Suzuki Sierra SJ50/SJ70 rather than “Jimny”), a MAP sensor isn’t fitted and isn’t relevant. These vehicles run a carburetted G13-series engine with no engine control unit, so there’s nothing that needs a manifold pressure signal in the way a later EFI setup would.

This position is backed by factory literature and parts references: the Suzuki Sierra/SJ413 workshop manuals of the period list a carburettor fuel system and vacuum-operated ignition advance with no MAP sensor component, the Suzuki Electronic Parts Catalogue for SJ50/SJ70 (late 1980s–early 1990s) shows vacuum hoses, dashpots and thermal valves but no manifold absolute pressure sensor, and mainstream aftermarket manuals covering 1980s–early 1990s Sierra models in AU/NZ describe carburettor tuning, not EFI diagnostics.

• Carburettor fuel system: fuel metering is mechanical, manifold vacuum only operates diaphragms and valves, not a sensor.
• Ignition advance: handled by mechanical and vacuum advance in the distributor, not ECU-controlled spark.
• EFI came later: local coil‑sprung (mid‑1990s) Sierra variants introduced electronic injection where a MAP sensor appears in documentation and parts catalogues.

A curve-ball worth noting: some 1991 Japanese‑market Jimny imports (e.g., JA11 with the F6A 660cc turbo EFI engine) do use a pressure sensor commonly referred to as a MAP sensor. The JDM EFI service manuals for those models show a firewall‑mounted pressure sensor feeding the ECU. So if someone’s got a grey‑import Jimny rather than a locally delivered Sierra, it may well have a MAP sensor.

Bottom line for a 1991 AU/NZ‑spec vehicle: there’s no MAP sensor to service or replace. If the engine’s running poorly, look to carburettor condition, vacuum hoses, ignition timing, or fuel delivery rather than chasing a non‑existent MAP fault. If the vehicle is an import with EFI, check the model code (e.g., JA11) and consult the EFI section of the corresponding service manual before ordering parts.

• Does a 1991 Suzuki Jimny/Sierra have a MAP sensor?
  Most AU/NZ‑delivered 1991 vehicles (Sierra SJ50/SJ70) are carburetted and don’t have a MAP sensor. Grey‑import JDM Jimnys (like JA11 EFI turbo) do have one.
• How can someone tell if theirs has a MAP sensor?
  Check the build plate/model code and look under the bonnet for an ECU and a small “pressure sensor” unit mounted on the firewall or inner guard with a vacuum hose to the inlet manifold. Carb engines won’t have this or an ECU.
• Rough running on a 1991 Sierra — could it be a MAP issue?
  Not on a local carb model. Start with vacuum leaks, carburettor cleanliness/adjustment, ignition leads, plugs, cap/rotor, and fuel filter. On JDM EFI imports, a failed pressure sensor can cause rich/lean running and a check‑engine light.