fminusmic

I've finally gotten to the point where I have finished fixing all leaks on my car, new suspension, belts, pulleys, compressor, etc.. The next step that I want to take is making some more power for my 1990 Honda Civic HB DX. I was planning to go from DPFI, then OBD 1, then swap a D16z6 head onto my d15b1 block and maybe get different cams/pistons on there.

I've read tons of threads and videos on doing the DPFI to MPFI swap and it seems like it'd be more difficult than swapping/resurfacing a head or going to OBD 1. I dont think that I'm too experienced with wiring; I can solder and connect wires + test voltage, but Ive never depinned something or messed around with the ECU/harness, except a radio harness.

How long would this swap take for a beginner like myself? Any hiccups that Ill experience along the way?

DaX

iTrader: (1)

If you are going to go to OBD1, you have to do the DPFI to MPFI swap anyway. I've seen people hack together a MPFI swap with twisted together wires run through the door jambs...not the way I'd recommend doing it, though. I spent a couple of weeks doing research, a few weekday evenings probing and verifying the current status of the wiring in my car, and then a full Saturday to do the swap. If you're looking for a boost in power that you're going to really notice, the MPFI swap isn't it. BUT...my car does run much better after the swap.

So, to answer your questions:

How long do I think it would take for a beginner? Somewhere between 4 hours and 40 hours, depending on how meticulous you are going to be about wiring, your comfort level, and how much preparation / verification you plan to do. Outside of reading manuals, wiring diagrams, and the internet, I probably spent about 20 hours on mine, but I fully unwrapped my engine harness and re-loomed it with all the added wires.

What hiccups? For me, depinning the ECU's "B" connector took a little while to figure out without damaging the pins. I ended up cutting a B plug off an EF in the junkyard and playing with that until I figured it out. You should plan to use shielded wire for the CKP and TDC sensors. Plan to spend more time and $ than you think - all the old writeups make it sound like you can get parts cheap - those writeups were probably done over a decade ago, so parts are harder to find. Plan to replace what is replaceable while you have it apart - hoses, seals, etc. I just did my MPFI swap about a year ago and think I spent about $550.

rallypoint_1

89ED

2point2

The best way to learn how to depin:

Cut off ecu plugs from u-pick autowreckers or a parts car and go for it. Don't learn on pins you need to rely on.

4drEF

It is very easy to overthink this conversion.
Just a few things are going on.

The intake manifold gets changed out.
2 more injectors are being added and if you use low impedance injectors you will e adding in an injector resistor box.
The distributor has a sensor to tell the ECU when to fire the 2 new injectors so you do a little wiring to accommodate for this.
The TPS rotates the opposite direction on DPFI and MPFI so those wires get flipped.
The pinout on the ECU is a little different so you need to do a little adjusting here so the wires go to the correct banks.

fminusmic

Dax - Yeah I believe you on how all the write ups are a bit old. I have about 3 junkyards around my city, but EFs are rare to find. They'll turn up at the Junkyard maybe once every 3-6 months. Even then, you'd have to get there early in the morning on that day to get parts.

Rallypoint - I would but the cheapest I found on eBay is about $200+. I could understand maybe like a hundred bucks, but idk

89ED - Honestly, if I get stuck, I might just end up buying that premade harness. But, I'll probably give it my best try, nothing has stopped me yet in fixing my car

2point2 - I will keep that in my notes. There's like 2 EFs in my junkyard and I'll take those harnesses.

4drEF - I'm planning to get a D16Z6 intake manifold, D16Z6 fuel injectors that come with it, EF Si distributor, P28 ECU. I read on different guides that if I get OBD0 injectors, I need that resistor box, but if I get OBD1 injectors (from the D16Z6), I don't need the resistor box. Is that right? Same thing for the distributor but with OBD1 ECU, different threads say OBD1 ECU should have a OBD 1 dizzy, but if I get the EF SI dizzy, it's obd0 ECU

Thanks everyone for the replies and comments.

4drEF

Correct.
You can use the high impedance injector from the Z6 with NO resistor box. Or you can use the low impedance injector (from EF) WITH the injector resistor box.

Correct again.
ECU and distributor do not mix between OBD0 and OBD1.
(A couple things to keep in mind if you decide to go OBD1 - OBD1 and OBD2 are interchangeable.
Distributors from D16Z6, D15B -SOHC VTEC, and D15Z1 have a unique bolt pattern).

DaX

iTrader: (1)

Yeah I pulled my IM, injectors, TB, and the part of the wiring harness for the injectors from a D16Z6 in the junk yard. For the distributor got to AutoZone and buy the Duralast Gold TD02U/TD18U (it has a lifetime warranty). Buy a PM6 ECU on eBay or the classifieds here (I got 2 for like $10 each just 6 months back).

89ED

Ronnie Cason

there are alot of great videos on youtube about how to do the conversion i would highly recommend looking op YoungStatic or Garage Built Hondas videos about the mpfi conversion as both of their videos are really detailed

fminusmic

Yeah, planning to complete this swap pretty soon. Got a real good deal on a head and complete z6 intake manifold. Only missing the dizzy and the ECU now.