Parts for your 1991 Mitsubishi Pajero-Fuel cap

1991 Mitsubishi Pajero fuel cap — what it does and how to look after it

The 1991 Mitsubishi Pajero does use a conventional fuel filler cap — not a capless system. This is documented in Mitsubishi factory literature (Pajero/Montero workshop and owner’s manuals covering early-1990s models list fuel filler cap inspection and tightening instructions), in the Mitsubishi ASA electronic parts catalogue (fuel cap listed for V1/V2/V4/V6 series Pajero), and, for Australian-delivered petrol models, by ADR 37/00 evaporative emissions requirements that necessitate a sealing cap working with the charcoal canister system.

On a ’91 Pajero, the fuel cap’s job is simple but crucial. It seals the tank to keep dust, water, and road grime out, helps manage tank pressure and vapour routing (especially on petrol models with an EVAP canister), and prevents fuel splash on rough tracks. It can also deter tampering if a locking type is fitted.

As part of regular servicing, it’s worth giving the cap a quick once‑over every 10,000 km or six months. Wipe the filler neck clean, check the cap’s rubber gasket for flat spots, cracks, or hardening, and make sure the cap tightens firmly. If it’s a ratcheting type, turn it until it clicks, if it’s a non‑ratcheting screw type, snug it until the seal is seated, then a little more — no need to overdo it.

• Tell‑tale signs it’s time to replace:
  • Noticeable fuel smell around the left rear quarter after refuelling
  • Cap won’t tighten or keeps spinning, missing or perished gasket
  • Visible cracks, a broken tether, or a warped sealing face
  • For petrol models, an intermittent check engine lamp linked to small leak/EVAP faults

Choosing the right replacement matters. Match the cap to engine type (petrol vs diesel), body series, and emissions setup. Petrol Pajeros of this era typically use a non‑vented, emissions‑rated cap that holds the correct pressure/vacuum relief for the EVAP system, while diesel variants require a cap specified for that tank and venting arrangement. Genuine or OEM‑equivalent parts listed in the Mitsubishi parts catalogue for your VIN are the safest bet.

Handy care tips: keep the gasket lightly conditioned with a silicone‑based lubricant once a year (avoid petroleum grease), don’t force the cap past its ratchet, and make sure the filler door closes without pinching the tether. If the filler door release is sticky, sort the cable or latch rather than cranking on the cap. A sound cap helps maintain fuel economy, reduces odours, and keeps the Pajero ready for the next big run.

Does a 1991 Mitsubishi Pajero use a fuel cap or a capless system?

It uses a conventional screw‑type fuel filler cap behind the fuel door. Factory manuals and the Mitsubishi parts catalogue list a dedicated cap for the 1991 Pajero, and Australian petrol models were built to ADR 37/00, which relies on a sealing cap for evaporative‑emissions control.

Are petrol and diesel Pajero fuel caps the same?

Not necessarily. Petrol versions typically need an emissions‑rated sealing cap compatible with the EVAP system, while diesel variants use a cap specified for their tank and venting. Always match by VIN or engine type to ensure the seal and pressure relief are correct.

What are the signs the Pajero’s fuel cap needs replacing?

Persistent fuel smell, a cap that won’t tighten or ratchet, a cracked or flattened gasket, or a broken tether are common flags. On petrol models, an EVAP‑related warning light or fault code after refuelling can also point to a leaky cap.