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Well at first, I thought I wanted the rocket arms on me, but now I think I want them whereever they'll help!
Meanwhile it seems like people who have J30A4 to JDM J30A swap problems, ( like I did ), are not clear about how I wired up the test solenoid.
I'll try I will try to clear that up.
Your old J30A4 engine had a VTEC solenoid (powered by a Green wire with white stripe) and a VTEC Oil pressure switch (a Blue wire with a white stripe and a Brown wire with yellow stripe wire) on the Oil Filter housing.
Your new JDM J30A engine has a solenoid on the rear cylinder head, but it mechanically stops the rear cylinders from firing when it's active.
Your original J30A4 computer wants to turn on a VTEC solenoid at 5000 RPM.
( In testing mine jumps from zero volts to 11.8 volts around 5000 RPM and then goes to 13.1 volts until the RPMs come back down )
The solenoid on the JDM J30A rear cylinder head is NOT VTEC, it will kill the rear cylinders when it gets voltage.
You will go from 6 cylinders firing, to 3 cylinders firing at 5000 RPM when the solenoid on the JDM J30A rear cylinder head gets voltage .
My test solution was to disconnect the solenoid on the JDM J30A rear cylinder head and give the computer a harmless solenoid to play with.
Wiring details:
On the original J30A4 Oil filter housing:
There was a Blue wire with a white stripe that was hooked to the VTEC Oil pressure switch.
There was Green wire with a white stripe that went to the VTEC solenoid
The computer wants to see voltage on the Blue wire when VTEC goes active.
The computer sends voltage to the Green wire to activate the solenoid.
You tie those together so the computer is able to power up the spare solenoid.
From wire harness Blue wire with whire stripe ----> Green wire on Spare VTEC solenoid
From wire harness Green wire with whire stripe ---> Green wire on Spare VTEC solenoid
Ground point G102 ------------------------> Housing on Spare VTEC solenoid
Verbose description:
If you connect the Blue with white stripe wire that was hooked to the VTEC Oil pressure switch on the original Oil Filter housing
to the Green with white stripe wire that went to the VTEC solenoid on the original Oil Filter housing
and connect those to a separate VTEC solenoid which is not really used,
then the computer will be happy, and will be able to rev past 5000 RPM.
If you tie the Green and blue wires together and connect to the solenoid on the rear head, you're stuck at a 5000 RPM cut off.
If you tie the Green and blue wires together and connect them to a spare VTEC solenoid and also connect the spare solenoid housing to engine ground point G102, then you are good all the way to red line.
That is what I'm trying to show in my pictures.
There is a nice picture of the VTEC Oil Filter housing here:
This info is really useful. I will ask my mechanic to follow the guideliness to make my engine run well.
Thanks for your helpful and kindness.
The red wire you see in the pictures doesn't actually do anything any more. I soldered a red wire to the Cylinder head solenoid so I wouldn't lose track of it, but it's not connected to anything
I put a VTEC Oil filter in a bag so the computer can control a solenoid and not throw codes.
I wired in this Solenoid so the ECU would have something to see & control instead of the solenoid on the rear cylinder head Running a spare VTEC solenoid in order to fool the ECU is not a great long term solution, but it proved that the problem with the engine shutting down is because that cylinder head solenoid is what's causing the problem So far the bag hasn't been sucked into the serpentine belt. So far.
The bottom line seems to be to if you swap in a J30 iVTEC motor in place of a J30A4 VTEC, you should pull the oil filter housing from the J30A4 VTEC and install it on the iVTEC motor.
You don't change the wire harness at all. You won't have VTEC, but the engine computer won't complain and it won't de-activate the back three cylinders at 5000 rpm
I tried to swap the rocker arms and the camshafts from the VTEC motor to the iVTEC motor and it didn't work.
The holes to mount the rocker arms don't line up.
[QUOTE=Samuel_77;52155461]The bottom line seems to be to if you swap in a J30 iVTEC motor in place of a J30A4 VTEC, you should pull the oil filter housing from the J30A4 VTEC and install it on the iVTEC motor.
You don't change the wire harness at all. You won't have VTEC, but the engine computer won't complain and it won't de-activate the back three cylinders at 5000 rpm[/QUOTE
I am doing this swap, so if I just use the original oil filter housing and plugs, and leave the ivtec unplugged on the head it should be ok
The bottom line seems to be to if you swap in a J30 iVTEC motor in place of a J30A4 VTEC, you should pull the oil filter housing from the J30A4 VTEC and install it on the iVTEC motor.
You don't change the wire harness at all. You won't have VTEC, but the engine computer won't complain and it won't de-activate the back three cylinders at 5000 rpm[/QUOTE
I am doing this swap, so if I just use the original oil filter housing and plugs, and leave the ivtec unplugged on the head it should be ok
I just Did this swap and am getting a VTEC code also. So basically if I just Install the oil filter housing from the vtec engine to the ivtec and just plug everything like normal then it should go away correct? Or am I missing A step?
Yes that is exactly right. Use your old oil filter housing and connect the plugs just like before. As long as you didn't change any of the original wiring, you should be god to go.
Yes that is exactly right. Use your old oil filter housing and connect the plugs just like before. As long as you didn't change any of the original wiring, you should be god to go.
okay I did That now and it’s still throwing the same code. Do I need to unplug the Ivtec also for it to work or is that separate. I plugged Everything in where it goes?
The ivtec should not be plugged in. I am confused about what the ivtec is plugged into.
In my case I had changed the wiring so that the ivtec on the cylinder head was connected. Which turned out to be a mistake.
I changed all my wiring back to the original and plugged in the VTEC on the old original VTEC oil filter housing.
My ivtec is not connected to anything. I can reach 6000 RPM with no codes at all.
If I were you I would re-check all your connectors and make sure the wiring was good.
When I was trouble shooting mine, I used a junkyard VTEC oil filter housing and plugged that in to make sure the codes were gone.
Look at some of the pictures in the thread above.
I just had a JDM J30a swapped into my Accord. I have a spare solenoid to wire in, but I am struggling to figure out where it need to be wired in on the harness. I have yet to find a blue w/ white wire or green w/ white. Could anyone please help me with what step I need to take next. Sidenote: Pictures speak a thousand words
If you had VTEC before the engine swap, don't change the wiring. Move the old VTEC Oil Filter housing to the new engine and plug in the connectors where they were before.
I tried the wiring change and it did not work and only made things worse.
I peeked down in the bay and it seems as if the original oil filter housing is connected and plugged in. I get a weird idle, all my instrument lights are on w/ check engine light and Drive light flashing. If I come to a stop, the car either over revs to get up to speed or I have to drop it into first myself.
There should be a wire harness on the passenger side of the engine that runs near the power steering pump down to the where the Oil filter housing bolts in.
As I recall there are two plugs on the VTEC Oil filter housing that need to be plugged in.
07-23-2019, 11:20 AM
Re: j30 ivtec swap for vtec engine
