HOW TO - ZE ENGINE SWAP (by Tommy D)
Tommy D last edited by
Due to obvious demand and my own enthusiasm on getting the UK ZE'd up, i will write an "idiots" guide to swaping a ZE, its piss easy
The Mazda MX3 is a fun car. The only problem is that even the V6 1.8 24v (K8) will get left behind by most GTi type cars…not cool
There is only one way to tune up your MX3, you need to drop in a KL ZE. The reason for this is the K8 is around 130bhp and an induction kit and exhaust although sound great do very little for performance.
The ZE is around 195bhp and can be swapped in a day by anyone with basic engine swap skills.
Before swapping an engine, make sure you get a good one and the right engine. I got mine from Nippon Spares, when i first contacted them i explained what i wanted and educated Ian on what exactly i wanted as to a Jap engine dealer a 2.5 V6 Mazda engine is a UK spec 165Bhp lump. The ZE is distinguished by its Rectangular branches on the inlet manifold as opposed to the thin Oval ones and the ZE has a number stamp beginning KL31 on the top of the heads and T/B
So once you have the ZE delivered, what do you do.......You put it in. People ask "what else do i need?" "what ECU do i use?" Its quite simple, as the engine is a KL-31 you need a KL31 ECU or even a KL36 ECU. The ZE will even run on the K8 ECU although this is temporary as you wont get the full ZE power. I also get asked "What AFM or VAF do i use?" For those who have no idea what AFM or VAF mean, they mean the same, AFM (Air Flow Meter) This is the cylinder that sticks into your airbox. Its job is to measure the amount of air going into the engine so the ECU (Engine Control Unit) can adjust the ammount of Fuel Injected. Why does this matter? Its because to get the best performance from your engine the Air and Fuel ratio must be regulated. The AFM on the MX3 V6 has a part number JE-50, You will be very happy to know that this is the same AFM that the ZE uses so you dont need to buy one :)
When you have the ZE, its a good time to prepare the engine for what you want to do.
eg. CAMBELT! (Get a new one on), If you want to? - Polish Aluminium parts, Grind Oil Pump Shoulder if you want to fit a U/D Pulley, fabricate 12-15mm Oil return pipe in Sump for Future Planned Turbo Conversions, change Spark Plugs and Oil Filter, etc.... Stock up performance parts, they are cheap so theres no excuse...
So now it comes to the engine swap,
1. Disconnect all wires and plugs that link the engine to the body, drain all fluids Oil/Coolant and disconnect pipes, Remove Radiator/battery etc, Throttle Cable, Gear Linkage, and Label every plug you remove in a way that you understand so you could connect it all up again! This will take time but saves confusion later on….
2. Crack off the Wheel Hub Nuts, jack up the front of the car and safely secure on axle stands so the front wheels are off the floor.
3. Take off the front wheels and remove the hub nuts
4. Disconnect the lower arms (also good time to fully check the bushes - if they are slightly worn drop some Corksport ones in)
5. Pull the Driveshafts and collect all the Gearbox Oil that will try and get everywhere, now the engine is ready to come out :)
6. Undo the bolts on the Manifolds / Downpipe so the engine can lift cleanly
7. Get the Hoist in Position, get some rope and connect it to the lifting hoops and lift to take the engines weight
8. Remove the lower X Member or if you have the space just disconnect the front lower engine mount which is on the X member, also disconnect the gear linkage if you have not already done so
9. Unbolt the other engine mounts, one at the rear and one on each side
10. Lift it out and put it next to the ZE on the floor, number the Gearbox bolts on top and bolthole as they can be a puzzle to put back due to different lengths
11. Swap all parts over, Altenator, distributor, etc so any parts missing on the ZE are replaced with bits from the K8. Most ZE's come with a Auto Wheel as opposed to the K8 Flywheel, swap the K8 flywheel as its lighter, or even better if you have a race Alu Flywheel, use that :) As for the Clutch, you should have a new uprated one to fit, if you dont, get one and put it on
12. Slide the Gearbox back onto the splines and stand back, bolt it all back up and have a 5 min rest, Sliding the box can take a few attempts and its not light
13. Installaton is a reversal of removal
14. Once it is in Connect everything back up using a new set of retainer clips for the driveshafts.
15. Top up fluids, Before connecting battery press brake pedal for 10sec to drain all power, Swap to KL31 ECU (inside kick panels - next to clutch peddle) Connect Battery
16. When you are satisfied that everything looks and feels right, and the Throttle operates not jammed wide open, start her up.
17. Sort the timing by fixing the disty where it should be using a Timing light
18. With the car in idle Wait for fan to cut in, switch off, Behind battery is a Diagnostcs box, Bridge "Ten" and "Gnd" Start again and adjust idle screw 200rpm above where you want it, When you are satisfied that you have the idle right 900rpm ish switch off, the Idle is set but now you need to adjust the TPS (Throttle Position Sensor) This is on the side of the Throttle Body, loosen the two phillips screws and turn the TPS until just before tha fan cuts in then tighten, done :)
This is an idiots guide in plain english, if this seems too much my advice is simple, get a professional to do it. Any garrage should be able to take the job on without any problems.
If you want any more detail i have just covered the basics here so as to not confuse anyone.
Check the ZE swap guides on www.mx-3.com if you get stuck anywhere, i did the swap so have much more detailed answers for any questions you may have…...good luck 8)
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