genosbro

hey guys, i'm new to this thread and i have religiously googled and search buttoned everything i could. No one has the same problem as me and its kind of frustrating. Without this site, i wouldn't know 90% of what i know so heres my first shot at a proper post.

PLEASE, let me know if you know of a thread I can read. I've looked at over 200.
(Please keep in mind I'm NOT here to waste your time and I hope that I am not.)

Model: Honda Civic 2000 EX
Motor: D16Y8 Head with a D16Y7 Block (Previous was a D16Y8 Full)
ECU: P2P OBD2b
CEL Error: (Not sure what number)idle sensor on the throttle body (what my mechanic told me)

Ever since I had the mini-me motor swap, my car has been idling unusally high. RPMS flucuate between 1k-2k. My mechanic did something that made the idle steady at 1.5K (too high for my comfort and the engine kicks like crazy when shifting between gears, my guess is because the RPMs drop so heavily) I've also had this problem in my old car.

My mechanic did a CEL scan and found an error reading that the throttle body idle sensor is dead, but I have heard of multiple cases online (specifically with 2000 SI Cvicis) where the ECU was giving a false reading because of the motor swap. I do know the owner of the engine block i just got and his civic (98) was running perfectly fine withit it. Although, his ECU was tuned and chipped with a jumper harness.

So with all that being said, I need to know if my engine needs a new ECU for the D16Y7 Block to work properly with the IACV/Throttle Body. Currently I have a P2P OBD2b ECU, and my mechanic recommends we try out his P2E (Chipped) but first he recommends I buy a wiring harness. I dont know which harness I need ODB2b to ODB2A? Some people say to buy a ODB2b to ODB1, so I can use a P28. (which i dont know the exact difference) I think its to keep the VTEC.

Also, i dont know how well the success of the swap went because the Y7 Block i had swapped into my car had a vaccuum tube running to the INTAKE and he said there was a valve of some kind attached the Y8 Block that is not there on the Y7 block so he plugged both tubes up. I dont think that is a good lead on trying to fix my idle or not. Can someone please explain this? Is there an incompatibility between these two types of motors? I'd think not.... considering alot of people do swaps like this.

EDIT: I just read this on another post
"if your doing a mini-me in a obd2b the only ecu you can run with little problems thats obd2b is a 2000 si ecu

a obd2b ex ecu looks for knock and other stuff and will make the motor run stupid.....i tryed it.

its best to just get a p28 and a jumper"
Do you guys recommend the p28 + jumper?

apexi_rsx

you can not run a p2p on a y7 block with out running the vtec wires and you need a knock sensor and your iacv code is because the ex uses a 2 wire iacv not the 3 wire the y7 uses. you need a ex manual intake manifold or a z6...

apexi_rsx

even if u ran a chipped ecu .. you would still need a 2 wire iacv.. for least problems at this point run a p2e ecu until u can get the parts to fix it. You CAN NOT chip obd2 ecu's so hes filling u in with a buncha shyt... as for harness you work with the harness u have in the car and add from there. you do not need a jumper harness as both obd2 ecu's look for knock. your best bet is to get a chipped p28, wire vtec to the harness you have , and do a 2 wire iacv conversion...

kyden

there shouldn't be any difference if you swapped only the shortblock. the only thing they would need to add is the knock sensor.

sounds like someone botched the swap.

genosbro

So wait, the intake manifold is the part that the IACV is located on? I thought that was the throttle body? The intake i have is the same intake i had before the swap, if you're talking about the part thats behind the head (which has the IACV on it) I'm not sure if thats the same one i had on my Y8 or not. I didnt swap anything but the block. So with my head still a Y8 would'nt my IACV still be a Y8?? Meaning i still have a 2 Wire? (And wouldn't need a wire conversion?)

Alot of questions are left unanswered, im not even sure if the new Y7 block i got had a IACV on it already. I'd have to ask my mechanic who did the swap, but im pretty sure everything but the block is the same, (Intake, IACV, Head, Tubes, Wires, ETC.)

As far as the knock sensor I believe my knock sensor is already on my Y7. It looks little rusted so im assuming it was either on there already or my mechanic took the one from my block and installed it. I see it on the left side behind my engine head. near one of the valves/injectors, and there is a wire running to it which has a green plastic around it.

Does the 3 Wire IACV have anything to the with the block or does it only communicate with the head? If i do have the same manifold i might still have a 2 Wire setup, what could explain the high idle?.. Bringing up the tube that the mechanic plugged up, its a tube coming straight from middle-back part of the engine head and it looks like it was supposed to run to the intake. (Considering there is a tube running from the intake that is also plugged) If i extend both tubes toward eachother they are about 2 inches apart. I'm thinking this tube on a Y7 Head is a little longer then the one on my Y8 head. Perhaps these two tubes are causing the high idle because of the lack of air or coolant running? (im not sure if its an air or coolant tube)

genosbro

The previous owner had a jumper harness converting it to a different ECU (The kind is unknown sadly he junked the car with the harness and ECU in it!!! IDIOT, sorry) the chipped p28 and wiring vtec sound like a good idea and it most advised by others. But how would i begin on wiring vtec, where do theres wires come from? Are they in the harness? And if i switch to a p28 doesn't it not have a knock sensor detection? I've read somewhere you need a knock detector to run vtec, is this true?

genosbro

I believe there is a knock sensor on it.... im not sure if the prev owner had one or if he just put mine on it from my Y8 block... Is there any possible way there could be a alternative location for the knock sensor because when i look up pictures for the D16Y7 knock sensor it shows that its in a spot that differs from my location and looks a bit different. (i feel like im wrong and the knock sensor is difficult to locate without being under the car)

(EDIT) i just realized this picture is a b-series motor.
http://i18.photobucket.com/albums/b1...spinoza/ks.jpg
^ for instance mine looks like this one but its metal instead of black plastic, and from facing the engine from the front its on the back of the engine head. In this picture it looks like its in the front. ( i could be wrong as i cant tell which side of the engine hes on in this pic.
(EDIT2) Okay so just so you guys know again, I'm really trying not to waste anyones time but i have gone over this thread
https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/%5Bfaq%5D-d16y7-y8-mini-me-write-up-pics-56k-maybe-not-735196/
and i have some steps on how to rewire the IACV from 2 wire to 3 wire, some steps to change the throttle body and the IACV from y7 to y8 and steps to wire the VTEC.

kyden

i'm not sure what you are rewiring? Did they use your original harness?

genosbro

Yeah original harness, my car was just in the shop replacing the axel and all 3 motor mounts. Meanwhile i talked to my mechanic, we're going to try to replace the throttle body sensor first before trying a Jumper harness and P28 ECU. Both of those might fix my idle problem. It is now idling at 1 on a cold start with a little RPM inscrease up and down fluctuation (as if i was turning my AC on and off). I just discovered today when the engine is hot my CEL pops on (at cold start, no CEL) and the idle either fluctuates between 1 and 1.5k or is steady 1.5k. Not sure what can change when the engine is hot? Maybe the coolant? Mechanic says there is no way i have air in my coolant considering i just got my motorswap and he drained and filled it completely. But if nothing works im going to try bleeding my coolant for bubbles.

kyden

if the CEL comes on, check the code.

your original harness should be 2 pin already. iacv rewire is for cars with a 3 pin.

genosbro

i'll let you know as soon as i check the CEL code again, but the last time it was throwing a code stating that the sensor on the throttle body is bad. im going to try to replace it. hopefully my P2P is giving a proper code.

yeah it took me a while to realize whether i needed a conversion or not but its look like i still have 2 wire, considering the block doesnt effect the iacv wiring.

HondaPartsHero

Take some pictures if the engine and post them.

b20bFourDoorCivicLX

he just answered you question, dont stress your self out anymore....


sounds like you dont know to much about what you got....take it to someone who deals with imports,swaps....

genosbro

I'm already in the process to doing a 2 wire conversion. But i have a question... when i unplug my IACV my car seems to idle perfectly. Its when i plug it in is when it irritates and stutters.

Another question i have, i checked the cable i have plugged into my IACV and it already is a 2 wire... If i were to convert anything how would i do it then? All the guides online dont really explain what to do if my car already has a 2 wire connection. Everyone on these forums is putting a Y8 Head on their Y7 vehicle and not a Y7 Block in their Y8 Vehicle