Remapping the Ford ECU on a 4/4 Zetec

The ShropMog 4/4 Zetec has the 1800cc Ford injection from the Silvertop Zetec, as used by Morgan in the first 1800cc Zetec 4/4's from about 1994. In the case of the ShropMog 4/4 (built in 1979), the donor vehicle for this engine was a 1994 Fiesta RS1800 and the Ford "EEC IV" ECU from that car was also retained.

This was all running nicely until a mechanical failure required an engine replacement. Best value was a brand-new 2.0 Zetec (1988cc) as originally used in the year 2000 Ford Focus. This unit was fitted by Tudor Motor Bodies, of Market Drayton. Kevin managed to get the new engine running well, with the original Silvertop injection and RS1800 ECU.

Once the new engine was run-in, thoughts turned towards whether the 1.8 ECU was getting the best from the new 2.0 engine. This older style ECU is not suitable for reprogramming so it was decided to try fitting a piggy-back programmable ECU module. The popular Dastek Unichip was chosen and the Morgan 4/4 was taken to Aldon Automotive in Brierley Hill for the dealer fitting and rolling-road setup.

The "before fitting" power run showed a healthy 146 BHP and 161 lbft torque. The team at Aldon fit the piggy-back Unichip-Q by connecting its mini-loom into the Ford wiring for the ECU. They then set up the Unichip to optimise the fueling and timing to suit the engine and any other mods you may have. If you fit more modifications in the future, you can go and get the Unichip reprogrammed.

After fitting the power was increased to 159 BHP. The torque was slightly increased to 163 lbft but more significantly, the torque curve was wider and flatter, over the rev range. This is pleasing as it is at what is considered the achievable power limit of this engine with standard cams and the Ford injection system. The difference is noticeable under normal driving conditions.

[ Piggyback ] LEFT: The Unichip Q piggy back computer mounted on the Ford ECU and connected by a short loom. BELOW: The results from after the ECU timing and fueling has been corrected.
[ Results ]

Fuel Pressure Regulator

The standard Fuel Pressure Regulator is installed on the fuel rail on the 4/4 Zetec. FSE make a direct-replacement kit (VK-384-Z1-H) Power Boost Valve. This is a rising rate, adjustable regulator that increases pressure 1.7 times quicker than standard. The idea is that it accurately tracks manifold pressure, making the engine more responsive during acceleration. At other times, the ECU monitors the exhaust and adjusts the injecor pulse so overall fuel economy is maintained.

[ Sender ]
A sender unit replaces the original valve, on the fuel rail. The standard return coupling is blocked off and a high pressure braided hose runs to the valve unit. (the kit comes with non-braided hose). The vacuum line can be seen (blue).
[ Valve ]
The valve itself has been mounted on the bulkhead, with the bracket supplied in the kit. The feed from the fuel rail and the vacuum line are connected. The third connection is the fuel return line. On the top of the unit is an adjuster, letting you set the fuel pressure as required.

This kit is widely available on the internet, compare prices and watch out for VAT.