Hondata

I took on this H22 swapped 1992 Prelude, it was originally a non-vtec car and I was not a part of the swap what-so-ever. They have spent thousands, and it wasn't even running when it come to me. I have atleast fixed some vacuum leaks and replaced injectors because nobody knew what injectors it had, and they looked mismatched to me.

I have finally got the car running, and driving. It did not have VTEC spool wired up, so I ran a wire from A4 to the spool before this test drive. Every time we hit around 4500rpm, the car acts like it hits a hard rev limit. Please have a look, and share any advice. I am wondering if maybe the VTEC oil sensor is doing this, or something else. I have read about limp mode and been through the forum for weeks reading about this stuff. I am tech savvy, wiring savvy and have been around tuning for quite some time. Also, the wideband shows we are running a little rich, but I was doing that to be "safe" until we get on the dyno.

Skunk2 Intake
Skunk2 Throttle Body
Skunk2 4 Bar Map
Skunk2 Grams 550cc Injectors
Resistor Box bypass harness
Stock Internals
Full Exhaust
h22 on S300

Based on your description it sounds like a ground issue, and it is grounding through the vtec solenoid and when VTEC engages it rev limits. Check the thermostat housing ground and all other grounds attached to the engine.

After reading some stuff I'm concerned I should not have wired the A4 directly to the spool. A4 had a wire color I'm not familiar with and someone had cut the wire they ran with it. I'm gonna have to look into a relay and add it properly as well as make sure my grounding is working right.

I did check ground in the oil pressure sensor and it had good continuity. This swap is also wired to use an internal coil dizzy before I ever got it.

So, it seems like even with VTEC unplugged it was doing this, although the VTEC spool wiring was hooked up it did not terminate in A4 on the ECU. I have no idea where the green/yellow wire on this harness is ending up because I cannot find the other end of it. The only other yellow/green wire I am seeing is going to the dizzy. Do you think this wire is terminated somewhere that I cannot see and causing the issue? This harness obviously was swapped in also, with the motor swap because it was a 92 chassis with non-vtec motor and now it's a 93 vtec motor inside of it with a s300 and the vtec wiring is there and whole harness is like just sloppily put in.

Spunkster wrote: Thu Apr 24, 2025 9:04 am Based on your description it sounds like a ground issue, and it is grounding through the vtec solenoid and when VTEC engages it rev limits. Check the thermostat housing ground and all other grounds attached to the engine.

Hello even with this vtec unplug and looking all through the tune for any rev limits it still is revving to 4500 and stopping

You have launch control set to always on. Disable it and reupload and try again.

I am not sure I see what you are talking about, I will look again. VSS isn't working right either.

print3dnc wrote: Thu May 08, 2025 5:47 pm I am not sure I see what you are talking about, I will look again. VSS isn't working right either.

Yep, you hit it head on. That fixed the rev limit; but did u see any causes of idle surge?

That is most likely an air leak somewhere.