Modification Modification
Car: Ford | Fiesta | CX (Mk3) | L | Hatchback
Engine: CFI | 0 | Inline 4 | N/A | Petrol

1.1 Petrol to 1.8 Endura TDi project

My current mk3.5 wasn't a particularly fantastic example, it had started out its life as a 1.1 base model in to which a 1.4 CVH had been fitted. Who ever had done the conversion had attempted to use the 1.1 CFi unit to run the engine, and without any other sensors. I'm not surprised it was sold as an 'unfinished project'. My Dad and I collected the car from Liverpool on a flatbed trailer as it was basically a rolling shell, but the car was an ideal base for a runabout as the body had no rot whatsoever just an extensive collection of dents and scrapes. For £100 it was a bargain.

I had had owned a string of 1.8D Fiestas previous to this project, and had just intended to fit the N/A engine and be done with it...until Dad suggested it would be interesting to fit the TD version. Performance and economy, now this sounded like a good idea (they always do at the start) and so the project began.

Selecting a 1.8 TD donor engine

It is crucial that the correct engine is chosen to avoid unnecessary complications. The most suitable engines are the indirect injection series but even amongst these engines I noticed a large number of revisions, particularly of the Turbo itself.



The indirect injection engine was fitted to the following vehicles:

 Car   Years Fitted   Power output (PS)   Suitable for Fiesta 
Sierra DD (Mk2) 1989-1993 75 No1
Escort/Orion DA (Mk4) 1989-1990 75 Yes2
Escort/Orion EA (Mk5) 1990-1995 75 & 88 Yes2
Escort/Orion FA (Mk6+7) 1995-2001 70 & 90 (Endura-DE) Yes
Fiesta EX (Mk5) 2000-2001 (Endura-DI) 75 Yes5
Focus GA 1998-2005 70-90 &115 (TDCi) Yes4
Mondeo FD (Mk1) 1992-1996 75 & 88 Yes3
Mondeo GD (Mk2) 1996-2000 90 (Endura-DE) Yes

1The Sierra engine has manifolds designed for a longitudinal installation and thus is unsuitable for installation in to a Fiesta.

2Although perfectly suitable for Fiesta installation, two additional modifications must be made that are not required on later engines. The placement of the EGR valve on these early engines is such that the Fiesta brake link bar will be fouled. The valve must be removed and blanking plates welded on to both the inlet & exhaust manifolds.
Further consideration must be given to the Fiesta brake servo as it is in the way of the standard intercooler. The solution is to cut the brake link bar and extend it by 2" and re-mount the servo to suit.
Another point worth making is that the exhaust down pipe can run very close to the Fiesta heater matrix hoses, and some revisions of Turbo mean that the down pipe fouls them completely. Measurements must be made prior to purchasing an engine to determine suitability.

3The changeover date to the later type Endura-DE engine is 1995, identification can be made by the cam cover which will read 'ENDURA-DE' instead of 'DIESEL' on early engines. For early engines see note 2.

4The focus had the Endura-DI engine (A direct-injection version of the Endura-DE). The basic block is the same so this can be fitted to a Mk3, however the fuel pump is fully electronic and so the entire engine management system is require. This also applies to the later TDCi engine (A common-rail version of the Endura-DI).

5The Mk5 Fiesta TD engine is the same Endura-DI unit as fitted to the Focus, but without the intercooler. The same fitting notes apply.

I chose the latest engine that I could find, and this turned out to be an Endura-DE Turbo (Ford also call this the TCI) from a late 1999 Mondeo. The Endura-DE shares many components with the earlier engines but revisions of note are the Turbo and oil system. The Turbo features a more compact EGR system that lends itself to a Fiesta installation, the Mondeo was also fitted with a cat which was located straight under the turbo meaning the down pipe poses no clearance issues with the Fiesta heater matrix hoses. The oil system is also revised to use 5w30 oil (note a change in oil pressure switch colour, black on early engines and green on Endura's). This reduction in viscosity helps fuel economy & throttle response, and helped raise engine output from 88ps to 90ps.

I took a large number of photo's of the engine when it was still in the scrap Mondeo as at this point I did not know what was required to install the engine in to a Fiesta. I have included the images here in case they are of any use to readers who are performing the TD conversion:

Conversion details

The following sections list the areas of the conversion which require attention or modification.

Brakes, suspension and wheels

Endura TDi conversion

Standard 1.1 suspension and brakes are not ideal for a 1.1 and are definitely not suited to something with nearly twice the power and 3 times the torque. For a simple and cost effective upgrade I used parts from a 1.6 Si.

Parts swapped over from the Si included the front anti-roll bar, suspension struts & springs and the brake discs & calipers. The struts are twin tube gas filled where the 1.1 has single tube oil filled. The Si brakes are the same diameter as the 1.1 but are vented for increased fade resistance. The front ARB considerably reduces body roll.

Charge cooling

The intercooler positioning on all of the 1.8TD engine series leaves a lot to be desired, maybe not from where Ford's accountants were concerned but certainly from a performance perspective. The cooler is positioned directly above the hot turbo and no vehicles originally fitted with the engine had a bonnet vent, just an ineffective length of plastic ducting leading from the slam panel.

Endura TDi conversion

I wasn't happy with the Ford intercooler so I settled on some kind of front mount intercooler (FMIC) as this would give best performance.

I had a Saab 9000 cooler in the garage which came with some Saab parts I had purchased previously to use in another turbo conversion. The cooler itself is of tube and fin construction with a thin core and very large surface area. The end tanks are plastic and so not ideal for high boost, but would be more than adequate for standard 13psi of boost.

Endura TDi conversion

Fitting the cooler involves modifying the front of the car somewhat as a substantial amount of metal needs to be removed in order to let the cooler sit in-between the bumper and radiator. I found the optimal position for the I/C was upside down with the outlets passing underneath the front cross member.

The image above left illustrates where the metal needs to be removed. I cut out the centre section of lower valance completely but left the mounting bracket attached to the cross member. When hammered flat the valance mounting bracket made an ideal lower rest for the I/C (right).

Endura TDi conversion

I covered the cut lines in the valance with 2 pieces of rubber house, along which I made a slit so that they fitted snugly over the exposed metal. The front bumper required cutting to clear the I/C, for this I used a jigsaw and marked the bumper with drafting tape. Careful cutting of the bumper meant that the cooler required no brackets and was held firmly in place when the bumper was bolted up to the car.

To make the installation a little neater I sprayed the exposed sections of the cooler black. As the car is a dark colour anyway, the cooler was quite stealth given its the size (left).

The I/C outlets are on either side, and I used a 1.3 KA throttle body hose (reducing 90o bend) on each to point the outlets up towards the top of the engine bay, from here straight section of tube could be used. One line runs in the O/S front wing behind the headlamp, and the other up in front of the gearbox. I found Rover 400 TDi boot hoses were ideal for linking the engine to the intercooler lines. Photo's of the plumbing can be found in the completed installation section at the bottom of the page.


Endura TDi conversion

With regards to engine management, the TD engines can be put into 3 groups: purely mechanical (pre 1993), pre-EEC (1993-1995) and EECIV/V (post 1995). Note that despite being fitted with an Engine Management System (EMS), the later engines still had mechanical fuel pumps.



Purely mechanically managed engines used no electronics other than the usual fuel shut-off solenoid which is required to stop the engine. Fuel enrichment during cold conditions is managed by a wax stat that actuates a cable which in turn moves a lever on the fuel pump to regulate the amount of fuel injected at idle. Idle speed is managed by a vacuum operated diaphragm, a crude arrangement linked via a control cable to a lever on the fuel pump which adjusts the idle speed. These early engines can utilise the existing Fiesta diesel wiring without the need for modification.

Pre-EEC and EECIV/V engines use an EMS (Engine Management System) similar in operation to that found on petrol engines. In fact post 1995 cars began to use the same EECIV EMS that petrol models were are with, and this was updated to EECV at the same time as petrol's in 1999. Pre-EEC engines used a different kind ECU that was unique to the TD range (above right).

Both EECIV and pre-EECIV systems utilise the same inputs and outputs, with the exception of the needle lift sensor and idle speed motor that were introduced with EECIV. The sensors/inputs and actuators/outputs used by the systems are listed below:

Sensors/Inputs Actuators/Outputs
Dual pressure switch (A/C) A/C Wide Open Throttle (WOT) relay
Engine Coolant Temperature (ECT) sensor Cold advance relay
Engine speed sensor Diesel idle speed motor1
Fuel Lever Variable Resistor (FLVR) Electronic Vacuum Regulator (EVR) solenoid valve
Mass Air Flow (MAF) sensor Engine cooling fan relay
Needle lift sensor1 Fuel heater
PATS module Fuel Injection Timer Solenoid (FITS)
Stop lamp switch Fuel pump shut-off solenoid
Vehicle Speed sensor (VSS) High speed engine cooling fan relay
Pre-glow indicator lamp
Pre-glow relay

1 EECIV/V (Endura-DE engines only).

The EMS controls auxiliary devices including the cooling fans and glow plugs, and unlike N/A engines the glow plugs are kept powered for a short period after the engine starts in order to improve cold engine performance. These basic functions aside, both pre-EEC and EECIV/V operation can be split into 2 core functions: Idle speed control and Injection timing.

The Idle speed control function takes input from the VSS and ECT sensor, the information is processed by the ECU and idle speed is adjusted. Pre-EEC systems use the same vacuum diaphragm as mechanical systems, but employ an EVR in the vacuum line to modulate the amount of vacuum the diaphragm sees and in turn the idle speed. EECIV/V systems take this idea further and use a motor & control cable to move the idle speed lever, the benefit of this is that idle speed is dynamic and free from the linear adjustment relative to engine vacuum that limited earlier systems.

Injection timing adjustment is made by monitoring engine load which is calculated from mass air flow. This applies to both EMS's. Corrections are made for engine temperature (ECT) and 'throttle' position (FLVR). EECIV/V systems employ a needle lift sensor, this is an eddy current sensor built into the injector from which the ECU can read injection pulse width and duration, and is utilised to further increase the accuracy of injection timing.

The EMS's alters injection timing within the lower RPM range and when the engine is cold in order to reduce exhaust particle emissions. As engine operation is not fully dependant on the EMS, this raises the question; can a pre-EEC and EECIV/V engine run successfully without an EMS? The answer is yes, I have tried. Performance is not significantly affected and cold starts are no worse than a N/A Fiesta diesel. Black soot out of the exhaust is increased, but is certainly no worse than earlier engines. If you wish to take this route then the standard Fiesta diesel wiring is sufficient and will require no modifications.

Endura TDi conversion

Despite having chosen a EECI/V engine (Endura-DE) I made the choice to use the pre-EEC EMS, this was to avoid complication with Ford's PATS (Passive Anti-Theft System). I removed the whole engine bay loom and pre-EEC ECU from a 1993 Mondeo TD and the photo left shows the loom I removed from the engine bay.

The Mondeo engine bay loom keeps the whole EMS separate from the rest of the car loom making it simple to remove for a conversion. The engine loom is further separated into EMS and power sections.

Endura TDi conversion

What I did first was to work with the power section and remove the pre-glow system from the fuse/relay box. The wiring is of a heavier gauge than normal to take into account the glow plugs are used for a length of time after the engine is started, where the Fiesta plugs work for a time & temperature controlled (read short) duration.

The photo right shows the Mondeo pre-glow relay, this is fed from the battery via a substantial fuse module within the engine bay fuse/relay box. The bank of 3 fuses also served other engine bay components, so the two superfluous were be unbolted and discarded.

Endura TDi conversion

With the pre-glow system separated from the rest of the loom, it could be modified to suit the Fiesta engine bay and mounted in place. The front slam panel proved ideal (left). As my car was originally a petrol model I had to run a wire to the dashboard to illuminate a spare lamp on the instrument cluster, to signify when the glow plugs were on.

Next I separated the EMS loom from any parts not required for the Fiesta installation. The engine bay loom removed from the Mondeo included connections for devices such as headlamps, horn, wipers etc. which are already part of the Fiesta electronics system.

Endura TDi conversion

The EMS wiring was separated from parts that weren't required in the Fiesta installation (headlamps, cooling fans etc). This was done with the aid of a wiring diagram and by stripping off the loom tape and isolating the relevant wires. I then modified the EMS loom to suit the Fiesta engine bay, and mounted the ECU on the O/S inner wing (right).

Connections to the car loom comprise switched live's for the ECU and fuel shut-off Solenoid, and a feed for the pre-glow indicator lamp. Please note that the fuel pump shut-off solenoid is a secure device on the EECIV/V engines (Endura-DE), and not of the conventional type.

The Endura-DE fuel shut-off solenoid is a 3 pin device that is linked to the Ford PATS system by 3 black wires and does not respond to a switched 12v supply as normal. The solenoid is protected by a substantial security cage (for anti theft purposes) that is held in place with self shearing bolts. I removed the cage using an air grinder and cut off tool. The security solenoid can then be removed and replaced with a traditional type from a matching fuel pump (either Bosch or Lucas CAV) which is de-activated by a 12 supply from the ignition as per the standard Fiesta installation (Black or Black/Blue wire) .

Endura TDi conversion

The final modification required to use a diesel EMS is to drill the B5 flywheel so that the engine speed sensor (called CPS on petrol engines - Crank Position Sensor) can generate a signal for the ECU. This is necessary as I have retained the B5 gearbox and matching flywheel, and as the B5 gearbox was used only with N/A engines it has no drillings for the engine speed sensor.

To accurately reproduce the drillings from the larger MTX flywheel I bolted it to the B5 Fiesta flywheel and drilled through the MTX flywheel (left) and into the rear of the Fiesta flywheel to a depth of approximately 6mm.

A side benefit of having an engine speed sensor is that a tacho can driven from the signal. The flywheel has markings at TDC and BDC, so a direct feed from the engine speed sensor will be engine speed * 2, therefore a suitable tacho must be chosen to match.

Engine Cooling

The Turbo water pump is slightly different to the N/A version, the inlet exits above the fuel pump as apposed to the right of it. I used a combination of Mondeo hoses and Fiesta hoses joined using spigots to create a suitable join between pump and radiator.

The TD engines are equipped with Modine oil to water cooler. Again I used a mixture of Mondeo and Fiesta hoses to plum this into the Fiesta system, I took the outlet of the heater matrix in to the cooler, and fed the outlet to the front of the engine where it joined the water pump inlet. This mirrors exactly the original Mondeo installation


Endura TDi conversion

The N/A 1.8 diesel exhaust is a little on the small side for the engine displacement and is certainly not suitable for a TD motor. When I purchased the donor engine it came with the cat/particle filter and a very short length of down pipe, and also the flexi section (right).

For the rest of the exhaust I chose an XR2i 8v system (right), the pipe fits snugly inside the TD down pipe and has a suitable size bore for the power output of the engine.

Endura TDi conversion

The first thing I did was to remove the honeycomb element from the catalytic converter/particle filter (left). For anyone intending to perform this conversion be aware that doing so will make the exhaust note considerably louder, but the good point is that turbo lag will be reduced. It's also worth noting that some form of respiratory protection should be worn, I wasn't too bothered as I've inhaled better things.

Removing the element took a combination of chisel and screwdriver to even loosen it. I found that working around the edge loosening the join between it and the metal wall helped me to break everything apart slowly.

Endura TDi conversion

The exhaust parts I had received from the breakers had been cut through with oxy-acetylene and so needed tidying with a hacksaw. The first step was to bolt the cat to the turbo to check for clearance, all was good and so the modification could begin

During this project I had no welder so enlisted the help of me mate Dave, a very talented chap who can weld a damn site better than I!

Dave worked by cutting pieces and tacking them in place on the car (right). Once the pieces were cut to shape and tacked in position, the exhaust could be removed and seam welded off the car.

Endura TDi conversion

It was found that the original Mondeo down pipe needed shortening by around 2" in order to let the main exhaust sit close to the underside of the body. Once this was done the exhaust could be complete, and looked very neat.

The photo left shows the completed exhaust, and how well it fits the confines of the Fiesta engine bay.

Fuel system

Endura TDi conversion

As my car was originally a petrol model I needed to convert the fuel system to suit a diesel engine. The diesel engines do not use an in-tank pump as the injection pump serves as both a lift and injection pump, therefore the electronic in-tank petrol pump is superfluous in this installation. The fuel tank is identical for both fuel types.

The diesel sender unit is different to the petrol version so I removed mine and stripped the sender and pump unit into its separate components (right). I planned to modify the petrol version to suit the TD installation.

Endura TDi conversion

The photo left shows the fuel pump bracket and sender assembly sans fuel pump. The uppermost tube that ends 2" from the mounting plate is the original petrol feed pipe which connected to the top of the fuel pump. The lower tube is the return, which is taken to the bottom of the tank to reduce noise levels.

I reversed these lines so that the feed was being drawn from the bottom of the tank and the return was at the top. The alternative would be to use the original feed and use a piece of hose that extended to the bottom of the tank, this would need to be kept secure to prevent fuel surge.

Endura TDi conversion

For Fiesta installation, at least in my case with the boost lines running parallel with the cylinder head, the standard fuel filter location needs to be reviewed. I chose to relocate the filter to the bulkhead.

I extended the fuel lines with rubber fuel hose and mounted the filter housing to the bulkhead with long bolts surrounded by alloy tube, to provide a solid base. As the filter is moved it also makes sense to move the fuel heater to keep the fuel lines as short as possible, the wiring for the fuel heater also needs to be extended to suit.


The Mondeo engine needs some alternations before it will even fit in the Fiesta engine bay. My engine came complete with A/C and PAS pumps which were not needed for my car, and unfortunately I couldn't foresee an easy way of retaining them as they are both driven off separate 10 rib serpentine belts, meaning the crank pulley is very wide and fouls the Fiesta chassis rail.

I removed the PAS pump and its associated bracket, and also the A/C pump which mounts to the sump. The Mondeo alternator can also be discarded as it is at the rear of the engine and will not fit in the Fiesta bay. As previously stated, the crank pulley needs swapping for a Fiesta item of which there are 2 types: Mk3 V belt or Mk3.5 6 rib type which was adopted to cure slipping problems on the early belts.

Endura TDi conversion

The Fiesta alternator and bracket can be fitted to the TD block as it is an identical casting to the N/A version. The Fiesta crank pulley must also be fitted. As I had a petrol engine I had to obtain the alternator, pulley, bracket and belt. I got them all from a late Escort van.

The Fiesta diesel engine mount is a direct bolt on, and once fitted the engine is ready to be installed.

There are 2 issues that will be encountered when fitting the engine; 1) the compressor outlet angle and 2) the inlet manifold.

Endura TDi conversion

The compressor outlet sits too far back and is very close to the Fiesta brake servo. This is easily fixed by slackening the compressor housing bolts and rotating the turbo into a suitable position (above left). The wastegate actuator is mounted on to the comp housing but there is enough range of movement in its ball joint to allow the compressor housing to be moved far enough.

The next issue to tackle is the inlet manifold, the Endura manifold fouls the O/S turret and so must be either modified or replaced.

Endura TDi conversion

My solution to the manifold problem was to use the inlet manifold from a Mondeo pre-Endura engine. The Mondeo manifold must be used as the Escort versions often have the outlet on the opposite side to where it is required.

The photo above right shows the differences between the two manifolds. They are both log style manifolds, but the difference is that the pre-Endura manifold exit is inline with the manifold body. It also has TURBO cast along its top face which looks nice when fitted. There are no performance differences between the two other than the location of the EGR intake.

Making EGR work between the Endura turbo and the pre-Endura manifold would not be impossible, but would involve a fair amount of fabrication. I don't like EGR on diesel's anyway as all it serves to do is coat the inlet manifold in thick layer of carbon, therefore I had the EGR intake on the inlet manifold blanked off (above left). The outlet on the exhaust manifold was also blanked off with a plate.


All TD engines are originally paired with the MTX75 gearbox, but to minimise complexity I retained the standard Fiesta diesel B5 gearbox. An Escort diesel B5 is identical so can also be used.

To use the B5 box the N/A Fiesta flywheel must be fitted and, this is a direct bolt on to the TD crank. I also used the standard Fiesta diesel clutch which proved to be more than adequate (same clutch as RS Turbo, part number 5027205). Please note that if the TCI engine management system is to be used then the flywheel will require slight modification. Please see the electronics section above for details.

Completed installation

New owner

When the time came for me to sell the car, I wanted it to be as 'standard' as possible to help make it easier to move on. As luck would have it, a fellow user had seen my post detailing the conversion and was interested in it for himself. James Forsyth had a 1.8 N/A diesel Mk3 Fiesta that he had modified in many areas, but was seeking more power but wanted to retain some economy.

I was more than happy to have a diesel engine instead of a 1.1, and so a deal was made and we agreed to swap engines between us.

Engine swap

The following photos were taken during the weekend in which the engines were swapped:

Engine bay detailing

The TDi project for me was a work horse and runabout for work, Jame's car however was a nice example which was already modified in many areas. James tidied up the installation further and treated the engine to a few chrome and polished parts which served to make the installation very show worthy, and certainly even more unique.


It would be a shame not to make use of the improved intercooling capacity that the large front mount offered, and James took the car to a diesel tuners to see what could be done to raise performance. Whilst at the tuners, the boost lines were improved and the boost was raised to 22psi and accompanied by adjustments to the injection pump. The results, in Jame's words:

"The rolling road gave an output of 150.1bhp when he lifted off, as the water temp was rising a bit, something we put down to the tiny fan in their workshop. They weren't geared up for cars like mine, more for motorhomes! The car pulled like a train, with incredible midrange that made driving it on the open roads a treat."

Further to the above tuning James installed both a boost and ACT (Air Charge Temperature) gauges, and these were neatly housed in a custom pod which sat in place of the centre vents.

© Mark Stewart, Monday 15th December 2003
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