ok i've spent at least 24 hours over the last few days researching this so, though i'm a noob...I'm kinda getting my head wrapped around it a bit.

i swapped a jdm d15b 3-stage vtec into my 96 civic ex. I kept the original y8 manifold. my dilemma is i don't have the ecu(p2j-003), wiring harness, or intake manifold that are meant to go with this engine. i currently have no way to run the 2nd vtec stage due to no wiring to control it. here are my questions in order of importance:

1) what is the best way for me to run that 2nd stage vtec with least amount of wiring work and best engine efficiency? buy p2j ecu or get a vafc controller to run it?
2) if i get the p2j can i just get a conversion harness from the p2p that i have?
3) anything about the y8 IM being on the d15b that may pose a problem for me?
4) any other advice or things about the swap that I should be aware of?

Thanks guys I tried to spend as much time researching this swap as possible as to not create a dozen posts asking dumb questions. so knowledgeable help will be extremely appreciated!

 

bump....no one???

 

i can answer your third question.
The Y8 manifold is bigger and has larger runners. It's actually better to use it. There should not be any problems with it.


and isn't the JDM D15B's ECU a P28? Or is your D15B OBD2?

 

Also, the 1st VTEC stage is for economy. IDK if it's possible, but if you can bypass the 1st stage and start out in 2nd stage, then go to 3rd stage, you would get better performance in the lower RPMs than the regular 3 stage VTEC, at the cost of a little bit of fuel. You might be able to do this with a different Camshaft.

Pasted from Wikipedia:
Honda also introduced a 3-stage VTEC system in select markets, which combines the features of both SOHC VTEC and SOHC VTEC-E.
At low engine speeds, one intake valve is opened off an economy lift cam lobe, and the second valve is just cracked open a little to help promote better swirl in the combustion chamber. Used in conjunction with a 5-wire, wideband O2 sensor, great fuel ecomomy can be realized.
At medium engine speeds, both intake valves open off the economy cam lobe with equal lift allowing the engine to produce more power, but at the expense of economy.
At high engine speeds, both intake valves are actuated by a high lift cam lobe and produce much higher performance than at the medium speed range, but at an even greater expense of economy.
The 3-stage VTEC system was only offered in the Asian markets and not in the US market at all.

 

thank for answer on #3...yes, the p2j ecu that belongs with this engine is obd2

 

had to update this thread, also looking for some help on another issue.
trustdestruction, your input led me into a ton of research on this engine and I've had a lot of progress cuz of it. I recently got the stock ecu that goes with this engine(p2j-003) and wired up the second solenoid to activate stage 2 vtec. works awesome and this engine pulls very nice!

my problem though is I'm not getting the fuel economy I was hoping for. after a full tank of driving like a grandma, I only got 31.5 mpg, while I was hoping for at least 38.

second problem is I can't fix my idling problem. cleaned my IACV, helped at first but once engine is warm, it idles between 1200-1500 rpm. I'm wondering if the y8 manifold mismatching holes to head are an issue. i was told after I swapped engine that I was supposed to fill in a couple holes with silicone. could a breathing hole on the head cause a weird idle or any other problem??

anyone's input is appreciated. thanks

 

Definitely. An intake air or vacuum leak will abnormally increase the idle speed. Such a leak also confuses the ECU because a higher than expected amount of air is allowed into the intake manifold.