1996 Engine swap with 3RZ JDM - idle issue

So I just got finished helping my dad swap a JDM 3RZ in his 1996 Tacoma. There were a few things on his original where we decided to use the JDM intake and exhaust manifold. Had to fab a little on the down pipe, but its fine now.

Our issue now is with the idling. Truck runs smooth but idles around 1700 RPM. I am guessing it has to do with the EGR valve stuff since we did not reuse it. Checked all over for vac leak and couldn't find anything. After driving when letting off the throttle the RPM would drop and rise a couple times but then stay steady around 1700.

The JDM has headers instead on the manifold and does not have the EGR hookup. There was also one 2 wire plug on the original intake manifold that was not there, not sure what it was, right behind throttle body and had about 3" of wire coming out of manifold.

Any suggestions that we could unhook or cap off to fix the high idle?

 

The sensor with the 3" wire is the most likely the EGR temp sensor. If you don't have a check engine light you don't need to worry about it. If you do get one later a simple resistor will trick the ecu. Removing the EGR should not make the Idle raise, if you have no vacuum leaks I would check the IAC to see if its dirty and getting stuck.

 

Yeah he has had a check engine light for years now after some stand up individual stole the catalytic converter... Just has a straight pipe now. I will check the IAC and I also went ahead and bypassed the coolant on throttle body but it seems like that may not work like some vehicles so I will put it back.

 

So you directly swapped the jdm motor in? Was your motor a 4 port or 8? Did you have any trouble at all? Or was your truck 8 port and the motor was also 8 port.

 

I did this a year ago. Try swapping out the throttle body with the old motor's.

Also I had to reuse my Intake Manifold as well.

 

https://www.tacomaworld.com/threads/engine-swap-project.569291/#post-19031168

I made a post in a different thread with some pics if anyone is interested.

 

Only the head ports and lower plenum of the intake that differ. If you have an 8 port manifold and a 4 port head, just split the manifold in half and use your USA top half in the JDM bottom half. CPU will compensate you can even run the 315cc pink top injectors.

 

I did have high idle after my swap and did the things mentioned above.

• Intake was put back together using the bottom jdm piece with top half being the US intake with throttle body.
• New IAC valve
• New pcv valve
• US spec egr valve

Once i got those things done it has been idling just fine .

 

Did you go from 300 to 315cc pink top injectors? I heard these computers do a pretty good job adjusting if going from brown to pink top.

 

They run perfectly with pink top injectors. I’ve done it in a ‘98 and a ‘00 3rz. Both all motor, one later s/c’d and the other later turbo’d. They stock ecu will trim the extra fuel with no issues.

 

I had the pink tops i brought over from my old engine. Been working just fine for the last 10k miles on the new motor.

 

Thanks for all the info! I ordered my motor yesterday $1400 jdm 3rz coil type. Just swapping the 8 port factory motor for a 4 port 55k miles. So excited! I feel like a kid on xmas!

 

So after looking at pics, it appears that the jdm intake manifold does not split like out USA ones, so I ca t just split them and use my top half. The motor is a 4 port and my intake is a 8. Did any of you use the JDM intake on the motor with USA harness etc?

 

Some I'm basically screwed and need to find an 8 port correct?

 

Your jdm 3rz intake split? Not like this one shown above?

 

When I got my JDM motor the intake DID NOT split I had to reuse my Intake

 

So im screwed and need to find an 8 port or I have to try and re use the jdm one?

 

You can see if you can find a use 4 port intake from a US motor. I've read of guys using a 8 port intake on an 4 port head with success. I've never tried it myself so I can't speak with personal experience. It could be something you could try out yourself if you're willing to experiment.

 

I'll take a picture of my current intake and i think i have a picture of the original intake to compare but both of them split.

Do you know some information about the motor such as what vehicle it came from/year it is? I looked at pictures of motors for weeks before i settled on the one i thought was exactly like mine but 3rz has many versions out there and when i got the motor i had quite a few things i had to swap from my original motor: top intake manifold, oil pan, oil pick up, crank pulley. Once i got it in i used the original exhaust manifold and was good to go.

The only reason i used the original top intake manifold was because the jdm one was damaged and i iust swapped them and put new gaskets in and I was ready to go.

 

So with the exception of the egr sensor which I dont care about cause I have no o2 anyway, would I be able to use the jdm intake and just swap my TB on to it?