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This is a project that I have started and while continuing to learn about engine differences, ecu, harnesses, and working on these cars a little at a time, start this to document/troubleshoot the issues ran into while making these decisions for others that might be getting into the same situations.
Details:
1992 Honda Prelude with JDM H22A VTEC which believe was an engine swap as the wiring appears to have been redone (poorly) by someone and been having to manually fix wires going to the engine bay.
The car does run rough during initial start up, runs better when it is warmed up, yet loosing power at 4500+ RPM. The car did sit for years in storage and have replaced: new fuel pump, new fuel filter, new spark plugs, spark plug wires, and still losing power at the top end.
Next thought is to look at injectors and ECU programming (still very new to this) with the ECU being chipped from what can tell.
1996 Honda Prelude with H23A1 engine. Just got this car with known bad motor yet the body, interior, and electronics look much better then my 92. Initial thought was to rebuild the H23A1 engine but after looking into the engine, appears this will be more costly/time consuming then doing an engine swap.
From reading on these forums and other forums about details on doing the H22A swap into this car, this is viable with my full H22A from my 92 however I am looking at other options which is buying an H23A VTEC engine and putting that engine in this car. Even crazier thought would be doing a K20/K24a swap into this car which might be too much to start with while learning about Honda engines, ECU, harnesses, etc. yet there is documentation available on these forums for this.
There we go, the start of the thread and will continue to update with pictures as the H23A1 engine pull is under way and decision is made on which engine swap to do whether it be the H22A out of my 92 or getting another engine ordered.
Current ECU on hand that came with the 96 Lude are: P14 and a P06. Will learn more about which ecu will/wont work and what is needed to get the right ecu to work with whichever engine if i do order one.
H23A1 Engine Picture is attached. Cylinder 4 damage from broke rod in H23A1 engine.
Any advice, encouragement, thoughts, greatly appreciated. Thanks everyone.
Basemaps might not run that well for daily driving purposes, they should be tuned correctly (if you have chipped ecu there).
And about:
H22A4 - H23 VTEC swap
Originally Posted by Prelude1897
I hope you still have your original H22A4 ecu. Here's a list of what you needed to swap from your old motor to this motor in order to keep it all as if it came in the car factory
I'm willing to bet there is an issue with either the vtec solenoid or the wiring for the vtec solenoid. I had the same issue back in the day and one of the wires going from the solenoid to the ecu had a split in it. The moment I fixed that all power was restored to the upper rpm. FYI my power dropped off at the same point 4500-5000rpm.
My advice, put the stock ecu back in the 92 with the h22a swap. Pop the vtec solenoid off and trace the wiring for any splits.
the vtec engine was not introduced until 1993. So using the stock ecu from the 92 is not feasible. you would need to get a 93-95 p13 ecu if you were to run a stock h22 ecu in the 92.
This also means that the wiring for vtec needs to be custom.
If you do have a chipped ecu in the 92, my guess is that the map on it is simply terrible. A professional tune will take care of that. But of course make sure all things mechanical are in excellent condition first.
From how I read this, just swap the engine from the 92 into the 96. Use the wiring from the 96, but you will probably need to change up the wiring for an obd1 setup, and get the P06 ecu tuned properly for the engine.
the vtec engine was not introduced until 1993. So using the stock ecu from the 92 is not feasible. you would need to get a 93-95 p13 ecu if you were to run a stock h22 ecu in the 92.
This also means that the wiring for vtec needs to be custom.
If you do have a chipped ecu in the 92, my guess is that the map on it is simply terrible. A professional tune will take care of that. But of course make sure all things mechanical are in excellent condition first.
Sorry, a stock p13 vtec ecu is what I was referring too.
From how I read this, just swap the engine from the 92 into the 96. Use the wiring from the 96, but you will probably need to change up the wiring for an obd1 setup, and get the P06 ecu tuned properly for the engine.
96 is obd2. He is much better off just finding a stock p13 ecu, run an external wire along the main harness (or tuck it in there) and plug the wire into the ecu. Problem should be solved (assuming that is the issue)
If his H22 was OBD2, I would say that, but he would need to swap oil pumps etc, where wiring it to OBD1 use should be simpler, was where I was going with that suggestion.
Two Preludes One Engine - Project
