Need information on 2.4 to 2.7 engine swap

I purchased a 1997 Toyota tacoma with a 2.7 5 speed 4wd after countless hours of testing and reading other inputs from this group it turns out the previous owner put a 1997 2.4 2wd cab onto im assuming a 1997 4wd frame with a 2.7 the engine wire harness and and ecu is for the 3rz my issues at hand are the 2 plugs behind the glove box connecting the cabs wire harness to engine. The truck has no cel light with the key on and the obd2 does not connect to scan tools after fixing the wire that goes to c.o.r the truck runs but you can tell it is not 100 percent right just looking for information from someone who has put a 2.7 into a 2.4 truck so i can maybe figure out what wiring inside the truck or the outside needs to be fixed to get the truck back on the road.

 

Your going to need the schematics from all the vehicles involved and look at each circuit there are no short cuts.

Each swap is always some what different .

Your problem might be in the 4th ECM plug where the cab harness needs repinned to match the 2.7 ecm . Your ahead of the Game the engine even runs . Most likely the OBDII plug is not wired correct or not at all.

Good Luck!!

 

I am assuming that is my issue the signal wire for obd plug is not in the correct pin on the plug for the 2.7 i will be checking that out thanks for the input

 

Getting into the middle of a swap with no notes or information is about the worst Thing I let myself get into. You just need to take your time and if need be walk away if needed.

 

Believe me i have been exercising that i have had this truck for a year and just work on it here and there when i have some spare time to mess with it. Im trying to find a ecm pinout diagram for a 97 2.4 and a ecm pinout for a 97 2.7. Engine side harness looks good but plug e5 22 pin connector seems to be where alot of my issues are.

 

I have a 98 2.4 that they put a 2.7 out of a 4runner in it...

they never changed the ecm, and it ran just fine...

I got it with a blown head gasket........

2rz blocks are so readily available......I just stuck one of those back in, still runs fine....
......same ecm whole time.....

However that was with the a43d Aisin tranny.....whole time....

if the tranny switches to the a340 one, which is common in the 4x4's.....that ecm may not shift right....


As far the OBDII port......mine will not connect unless engine is running and has always been that way.

 

I have tried the obd2 multiple ways and get no communication. The truck is a 5 speed so wont have to worry about transmission

 

So you have the underpinnings of a 6 lug truck with a 5 lug cab?

And the originater didn't keep the 6 lug electronics ?

 

pinouts atached

 

Apparently he did not they must of thought it was plug and play since the cab harness plugs in with the rest of the harness but once you start looking at the wires you can see real fast that it is definitely not plug and play

 

Is the 96 pin out the same as the 97? I have read over that pin out a little bit trying to piece it together but i have not tried anything yet hopefully this weekend i will have a little extra time to work on it

 

The 98's 2/3RZ went to a twin coil....



Table Of Contents (well.com)

 

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Well maybe the 2.7 is newer then i thought it has the twin coils but the ecm says 1997 i will check the pin outs posted and see if there similar to what i have

 

2.4's were switched over to twin coils.....mfg date 9/97 and on...
making these 98 models.....

Thats reason why vin is needed to order some parts if yours in built right at the model change border.....

 

The build month was 04 of 97 but as of right now i have the plugs to the computer re-pinned and have gained a check engine light with key on and i can now pull the codes up only thing it is showing is idle control valve issue and my bank 1 02 sensor is not reading and causing the fuel system to stay in OL

 

I have about the same problem. I recently bought a 2000 4wd with 2.7.... Only I just realized today someone swapped a 2.4 into it. It seems to run great. Only it's pretty weak and only gets 15mpg at best. So I took it to a mechanic a few days ago and found out the check engine light doesn't work. So he hooked his computer up and pulled up probably a dozen codes. Told me the A/f sensor was the best place to start because it was dead in the water. Some of the wiring has been taped, so idk if the sensor is bad, or just isn't connected properly. Its pushing way too much fuel. So much that I can smell it in my oil. Idk how its running so smooth. But it's way out of whack. So I'm wondering if I should try and find a harness for a 2.4?? And would I need a different pcm or do both engines use the same pcm with different harness? Not trying to butt in on the original... this just looked like a thread that i may get some kinda idea on what to do. At least it runs but 15 mpg is costing me quite a bit driving 150 miles a day to work.

 

When I bought mine it had the 2.4 replaced with the 2.7.

It ran fine with that same ecm.....no difference.

Same with the harness on the 2.4/2.7.....they are the same...

only the auto and manual differ from each other.


I would closely check the pcv valve and hose......if those fail it cause increased fuel and oil consumption.

It may not hurt you to go in clean/check/ and maybe replace some of the engine sensors........maf.......1st oxy sensor

You should be cleaning the maf sensor at least once a year anyways.....the wire sensor has dust and crap build up on it.

No1 reason these run bad when they get old is weak battery connection/ground......and shot leaking vacuum hoses...

 

My 2000 4wd is 5 spd man. If the 2.4 that was put in it was connected to an auto trans how could I tell, and would it need different sensors? Also I couldn't find a pcv valve on it. Just a hose going to the valve cover where I thought there should be one.

 

It doesnt matter what the 2.4 was connected to before.....

its the harness that makes or breaks the deal.......I assume they just dropped the engine into the old harness and engine bay...


the 2000's may have the screw in pcv valve.......the 99's and older like mine use the grommet......which sucks and has to be replace every few years......so you dont get a massive secret vacuum leak.....
definitely a trouble spot on the pre 00's..