I realize this has probably been beaten to death 100x. I'm looking at possibly putting the EX vtec engine out of a 95' into my brother in laws 94' LX. I'm not doing it for a big performance gain, more of a supply and demand situation(it'll save us both some money if it's not complicated). I'll have the entire donor car and hopefully that'll be enough for parts? I know several of you guys know this in your sleep so help a newbie out

 

Add two pins to your ECU plugs, for Vtec pressure switch/solenoid. Wire the Vtec pressure swtich positive wire (signal) to the ECU and the other to ground. Solenoid is one wire back to the ECU. Pins are A4 for the solenoid and D6 for the switch

If you use the Vtec harness, use the ex (internal coil) distributor. (someone correct me if I am wrong) You can run the wires to the shock tower plugs from the ECU. The engine harness will already be wired up for Vtec.


If you use the non vtec harness, use the non vtec distributor (external coil) and run your wires all the way to the pressure switch/solenoid. If you use ex 4-2-1 headers on the lx nonvtec harness you will need to move/extend the oxygen sensor wires to reach the end of the collector.

Hook up the Vtec ECU appropriate for your car (OBDI/II auto/manual).

This is a fairly straightforward swap for sure.

 

You will need a OBD1 POA VTEC ECU.

 

I'm sure this doesnt come recommended, but what if a person just didnt hook up the vtec selenoid/pressure switch? Would it run about like a standard non-vtec or would there be major issues?

 

It would still run but why wouldn't you want to hook it up unless you didn't have the ECU.

 

herp derp double posting like a fool

 

If you have the parts car, and both are OBDI (94/95) why not just use the complete harness/ECU from the EX into the LX? Seems easier than trying to ad wires. Pulling the engine anyway correct?

 

You got me, I've got the entire EX for parts......

 

If you are running the Vtec ECU it would throw a CEL and run like a non vtec engine, only like *** once you got into Vtec RPMs. Run the nonvtec ECU would runn like *** in general. Valve lift and duration are different on the intake side of the Vtec motor so the basemap would be off.

If you are going to use the Vtec harness (Easiest) you will still need to add the two pins (A4/D6) to the ECU harness, and the appropriate slots in the shock tower Canon plugs to get it to work, as nonvtec chassis aren't pre-wired for Vtec.

 

I'm not sure why you would swap a VTEC engine into a non-VTEC car and then not hook up VTEC......

Defeats the purpose doesn't it?

 

You have it easy(both cars at your disposal), just have to reference between the cars for anything that is different from the factory. Which should just be the head(VTEC EX vs non VTEC LX) and the additional solenoid wiring for the VTEC.
Pull the engine/harness/ecu from EX, place it into the LX. Plug and play as they say. Just tape and mark off everything you remove from each car so as you know where everything is supposed to go.

Check out Magestic Hondas parts site and start comparing anything you think is questionable between the LX and EX.

 

yea its best to just keep the vtec ecu and use it for the swap. yes, if u use the non vtec ecu it will run w/o vtec. But just use the vtec ecu with vtec engine.