98_ssbp

My friend has a 93 prelude si still equipped with the original OBD1 H23 nonvtec. The motor is approaching 200k and seems to be on its way out. We found a OBD2 H23 vtec Blue Top for sale locally that seems like a pretty good deal. We would only be swapping longblocks (still using the original H23 nonvtec tranny).

What is needed to convert the H23 vtec to OBD1?

This is what I was thinking:

-OBD1 H22 vtec harness
-OBD1 H22 vtec distributor
-OBD1 H23 nonvtec injectors
-OBD1 H23 nonvtec alternator
-OBD1 P28 ecu chipped with a H23 vtec basemap

Is there anything that I'm missing? Maybe some sensors that are different? I've never really messed around with anything H-series before, and I haven't found any solid info on this swap. Any input is appreciated.

thirsk66

iTrader: (2)

Nope sounds like you got most of it...goodluck on that swap

tzg

That looks good. The 93 should already have the wires for VTEC as that was the first year that they offered the H22, it should just be capped off. I'd also suggest swapping over to a manual timing belt tensioner, as the auto tensioner tends to fail.

Apex1972

use OBD1 H2 injectors instead of non vtec ones.
KS Tuned manual tensioner and youll be good to go.

92bluepreludeSi

i used my stock h23a1 harness when swapping in my bluetop and wired in vtec. You can use the H23a1 dizzy. Consider buying the KS tuned manual tensioner got one on mine and it is an amazing simple product. My bluetop didn't come with a vtec oil pressure switch so u might want to look into that aswell. if you have any other questions PM me.

snobordboy

Yeah, use the original wiring harness, dizzy, and alt from the H23A1, and you should have the vtec wiring from the ecu to the engine bay, just have to find it and connect it.

As mentioned, do not use the H23 non-vtec injectors, track down a set of H22 vtec injectors, or do something like rdx injectors or some kind of 450cc or so aftermarket injector.

A tune on a chipped ecu, or Hondata/ Neptune etc. is a great plan to go with as well.

92bluepreludeSi

also use the H23a1 upper intake plenum.

holmesnmanny

You need to be absolutely certain you get h22 obd1 injectors. The obd2 ones will look the same but they will make your car run like **** and can damage your ecu.

xduB95preludeSi

hey guys i know the thread is old but im a new owner of an h23 blue top with the p13 head not pde. no big deal thats not why im here. i need to be be ran on obd1 so i swapped over my h23a1 harness to the blue top and the upper intake plenum, dizzy, coolant hose neck, egr valve, modified the harness to accomadate the obd2 alternator. i switched drivers side mounts with h23a1. i just need help with some other wiring. the vtec for instance. i know these motors dont have a pressure switch, but does it need it for vtec to work on my obd1 set up? or so i jump or ground a wire or two and then im good? im not looking to get any codes. also i know the ecu pinouts and such, but can someone clarify HOW i add pins with wires to the harness? i have a vtec solenoid wire ran from the bay to my ecu and i also have the ecu pins from honda but i dont know what to do, i know its A4 but how do i add the pin? thanks in advance guys wish me luck. i was going to drop the motor in tonight but i could get the trans to angle down enough so i have to pull it out and adjust my chains and try again tomorrw.