So you want to be a cool guy do an MPFI swap on that old DPFI Civic you just picked up? Well, you’re about 15 years late to the party. Trying to gain that mythical 10 horsepower that you heard was cheap and easy to get? A properly executed MPFI swap is not exactly cheap, and while your car may run better after the swap, the difference isn't neck-snapping. At the end of last year I decided to finally do an MPFI swap on my 1990 Honda Civic DX Sedan, which has been my daily driver for over 14 years. I stayed OBD0 for simplicity. Here's what I think you'll spend in 2018 to get it done correctly. By correctly I mean soldered and heat shrunk connections, and all wiring run inside the harness.


Parts You Must Buy

• PM6 ECU ($20) – I found mine on H-T classifieds for $10 plus shipping. eBay had them for about $40 each.
• TD02U or TD18U Distributor ($185) – I don’t recommend going for the $50 eBay distributors. I had 2 bad ones in a row on my DPFI setup. AutoZone has a TD02U distributor in the Duralast Gold brand. This distributor comes with a lifetime warranty.
• Complete MPFI Intake Manifold ($100) – Go to a junk yard and pull an MPFI intake manifold with everything on it. By everything, I mean throttle body, TPS, throttle cable bracket, fuel rail, fuel injectors, fuel line, EACV, IAT sensor, MAP sensor, FITV, and support bracket. Along with this, get the portion of the wiring harness that goes to the fuel injectors. I just cut the injector wires where they went into the main branch of the harness. The chances of finding a stock MPFI EF in the junkyard is slim these days. I ended up getting my stuff from a 1994 Civic EX (D16Z6) at the local you-pull-it yard. If you get parts (specifically, fuel injectors) from a 92+ Civic, you won’t need a resistor box, as the injectors are saturated.
• Resistor Box ($20?) – I don’t know how much they are because I didn’t buy one – I used saturated injectors (which don’t need one). If you are using peak-and-hold injectors, you will need a resistor box. If you don’t know what saturated or peak-and-hold injectors are, do some googling.
• Intake Manifold Gasket ($10) – RockAuto.com or your local parts store.
• Spare DPFI Engine Wiring Harness ($25) – Having a 2nd DPFI engine wiring harness to go along with your stock DPFI wiring harness is great for stealing connectors, loom and other things off of. Junkyard purchase.
• 8-pin Distributor Connector Pigtail, Female ($10) – This is the round connector for the MPFI distributor. I couldn’t find one in a junk yard, so I just bought the pigtail from MonoTech.
• EG Civic Intake Tube ($5) – The intake tube that runs from the air filter box to the throttle body- you'll need this if you are running a stock intake, because the DPFI one is too long and won’t work. Junkyard purchase.
• EG Civic Breather Pipe ($5) – This is the pair of small metal tubes that are spot welded together – one runs from the valve cover to the intake tube (air), and the other connects the FITV on the throttle body to the coolant supply on the intake manifold. Junkyard purchase.

Parts You Should Buy

• PCV Tube A ($6) – This will likely be clogged, cracked and/or hard as a rock on the intake manifold you buy. If it isn’t damaged, it will likely be damaged after you remove it. Do yourself a favor and buy a new one. I ended up getting one from Honda that goes on an EG and it worked – P/N 1185-P07-000.
• PCV Tube B ($33) – This hose was also clogged and dry rotten on the manifold I got. I have no idea why this little hose is so expensive, but I went with an OEM one, also from Honda. P/N 11856-P06-A00.
• PCV Valve ($5) – RockAuto.com or your local parts store.
• Throttle Body Gasket ($5) – RockAuto.com or your local parts store.
• Injector Seals ($20) – RockAuto.com or your local parts store.
• Heater Hose ($8) – This is the hose that connects the thermostat housing to the intake manifold. I went with a Gates hose (P/N 18701).
• Small Coolant Hose ($10) – RockAuto.com or your local parts store. Replace all those small dry rotted coolant hoses that go to the FITV, IACV, etc.
• MPFI Throttle Cable ($35) – Honda P/N 17910-SH3-A91. You can probably use your DPFI throttle cable, but it will be long and messy looking. If you are doing an auto-to-manual swap also, you'll need a 5-speed pedal cluster - the MPFI throttle cable will not work with an auto accelerator pedal.

Supplies to Buy

• Wire ($20) – Buy some good quality copper stranded wire. A few different colors makes your life easier. You can get this from Mouser, Digikey, etc.
• Shielded 2-Conductor Wire ($30) – The signal wires that connect the 3 sensors in the MPFI distributor to the ECU need to be electromagnetically shielded. The DPFI harness already has the CKP and TDC wires shielded. Since you’ll be running new wires for the CYP sensor, you should use shielded wire. You can get this from Mouser, Digikey, etc. Can you run regular wire and not have issues? Maybe. Should you run shielded wire instead? Yes.
• Heat Shrink ($10) – get a box with a mixture of sizes of standard 2:1 polyolefin heat shrink from either Amazon or your local parts store.
• Solder ($5) – I like 60/40 tin/lead solder, and feel like 0.031” is a good all-around size. Amazon.
• Electrical Tape ($5) – get the good stuff, Scotch Super 33+. Amazon, local parts store, Walmart, etc.
• Antifreeze ($10) – you gotta refill your coolant system after you put it all back together. Local parts store.

If you buy everything I have listed here, you’re already looking at over $550.

 

Also...before you start the swap, you should be proficient with de-pinning Honda connectors. The majority of the OBD0 connectors are fairly straight forward, but I recommend the following websites/threads for more info on de-pinning at the ECU. If available, I also recommend practicing on some junk yard harnesses before you destroy your own.

ECU Pin Removal Guide - VTEC Academy

https://honda-tech.com/forums/honda-...n-ecu-1191491/