Although the Panda will fit any FIRE engine that FIAT was putting in a wide range of cars of that era in terms of engine mounts and gearbox, this swap is one that makes the most sense for the 4x4 variant in my opinion. The Punto 75 8V MPI engine is the swap requiring the least modifications, produces 19HP more than the most powerful Panda variant (1.1 liter) and unlike the 16V engine it will give torque on lower RPMs which fits the 4x4's intended purpose. Keeping the complete original injection system makes the electrical work much easier because the engine and the harness are one self-contained unit that just needs to get power from the car and connect some warning lights for your comfort.

There was no carburettor 1.2 FIRE engine in the Punto. Fiat phased carburettors out of the FIRE family before the Punto launched, so every Punto MK1 1242 cc engine is injected, but some engines used a single injector and some an injector per cylinder.

75 MPI versus 60 SPI

There was also a version of the engine in the Punto 60 of the same displacement that used SPI variant and produced singificantly less horse-power. Since old Punto's are abundant pretty much everywhere in europe it makes litle sense to opt for that variant, but I believe this guide should be applicable to that engine as well. The Punto 75 uses multi-point injection: four injectors mounted in a fuel rail, one for each inlet port. The lower-output Punto 60 uses a single throttle-body injector and different ECU.

All MK1 1.2 engines are distributorless wasted-spark systems. The Punto 75 has two coils mounted side-by-side at the gearbox end of the cam cover, with four HT leads running to the spark plugs.

Punto's were very popular cheap cars in many european countries, the Mk1 model was produced in 3.5M units over it's production lifetime and even overtook the Volkswagen Golf as the best-selling car in europe for a while. The 75 variant was one of the more expensive models so it is not as common as the 55 and 60 variants which were more easily available. That being said, the 75 can still be available for very little money as the car is looked as a beater and never really took off in the enthusiast circles.

The donors interior and health doesn't really matter, but obviously the better the car looks - the bigger the chance that the owner took care of it and serviced it properly. You should only be concerned if the engine is firing properly and works well on all revs to minimise cost and effort to get it to a nice working state. Either way you will be pulling it out of the car so there is absolutely no reason to not do a full service of all engine components while it is on the bench and easily accessible.

While you pulled the engine out on your bench, now is the ideal to replace and service the engine fully. You don't want to install it just to have a failure of a 10 EUR part that requires you to pull the engine again to replace it. Replace the timing belt, the spark plugs, clutch, thermostat, gaskets, seals, even get the head of the engine machined - do everything now when you have a chance to do it easily and cheaply!

When disassembling the engine make sure you label the connectors where they need to go so you don't forget how to re-attach the harness later.

You need to drop the existing engine out of the Panda including it's harness (relays, engine bay fuses). Essentially everything that is attached to the engine needs to go out, the only thing we will need is the gearbox so get it out and attach to the Punto engine. You should be able to drop in the Punto engine pretty much straight in on the same engine mounts as all FIRE engines should fit.

There is a metal holder on the Panda engine that is a bit different from the one on the Punto engine which you will need to replace. Also the throttle pulley holder that attaches onto the throttle body didn't fit from the Panda for us, so we cut half of Punto one (where it attaches to the throttle body), and half from the Panda one and welded them together to get the correct length where the throttle can be operated in its full operating range.

The Punto loom should remain connected to the coil pack, injectors, lambda sensor, crank/TDC sensor, and two-wire ECU coolant sensor. The ignition drivers are inside the IAW 8F.5T ECU; there is no separate ignition module.

The moulded white twin-relay box contains the main injection relay and fuel-pump relay. The ECU pulls in and latches the main relay, which supplies the coils and injectors.

Where both cars have the same basic sender function, retain the Panda wiring for the oil-pressure switch, coolant gauge sender, and alternator warning lamp. This can be wired through the square 10-pin connector as well, but that means pulling wires out of the Panda harness and is more destructive. Adapt the connector at the component where necessary.

The MPI camshaft has no mechanical-pump lobe. An electric injection pump is required and must deliver the pressure needed by the MPI rail. A standard inline 3–5 bar pump is commonly used; the rail-mounted regulator controls working pressure and returns surplus fuel to the tank via the return line. The solution to this is to put a different diameter fuel lines, or more easily put a fuel-pump that has a higher working pressure than the stock panda fuel-pump.

You can use the one off the Punto, but they are quite cheap so better just buy a new one for the Punto and install that into the Panda fuel tank. You will need to get the Panda on the lift, take off the fuel tank completely (remembering to mark the lines so you know how to re-attach correctly later) and replace the pump before re-installing.

Both Panda and Punto are fitted with EVAP systems, but they are implemented differently. The throttle body has a pipe fitment that will be connected to the charcoal canister via a EVAP solenoid operated by the ECU. You will need to use the EVAP solenoid that was set up on the Punto, but you will need to connect it to the charcoal canister on the Panda which is hidden behind the front-left tyre wall.

Alternatively you can close the fitment on the throttle body with some sort of a air-tight cap, but then the canister that collects the petrol fumes will be leaking it into the engine bay. The redneck way of correcting this would be to point the piping from that outside of the engine bay space which will still leak the fumes into the surrounding area, but prevent pressure build up in the tank. This is obviously less than ideal because petrol fumes are flammable, smell, accumulate in the area where the car is parked and not having the EVAP system connected will cause the ECU to not work well and throw an engine light.