idle pulsating problem after motor swap

97slvrhatch · Post by **97slvrhatch** » Wed Jun 29, 2011 5:12 am

so to start off i swapped my engine this weekend. i had a d16y7 and now i have a d16y8. after the swap i started it up and the idle was pulsating. the chech engine light was on and the code was the iacv. i took the throttle body off and cleaned the iacv with brake clean because it was dirty. put it back on and it seemed to better but still wanted to die when i firsted started from first gear. then i shut the engine off and went to drive it again and it did the same thing. so then i took the old iacv and the old iacv sensor from the d16y7 throttle body and swapped them out. it sounded even worse than before after i did that. so then i put the old one back on and it was a little better but still pulsating. any ideas on other things to try?

JustRob · Post by **JustRob** » Wed Jun 29, 2011 6:09 am

Are you using a 2-wire or 3-wire IACV on the D16Y8? What ECU? What engine wire harness?

97slvrhatch · Post by **97slvrhatch** » Wed Jun 29, 2011 6:46 am

JustRob;268415 wrote:Are you using a 2-wire or 3-wire IACV on the D16Y8? What ECU? What engine wire harness?

3-wire iacv. p2p ecu from a 97 ex. and the original wiring harness from the d16y7 (obd2a). i dont have vtec hooked up or the knock sensor but that shouldnt matter for the idleing problem?????

97slvrhatch · Post by **97slvrhatch** » Wed Jun 29, 2011 7:44 am

so i did some more research on the iacv and it says that the manual ex motor has 2 wire iacv. the harness that i am using from the d16y7 is a 3 wire. im guessing this is why its throwing the code and i am having idleing problems. how do i fix this?

civicex · Post by **civicex** » Wed Jun 29, 2011 2:22 pm

97slvrhatch;268418 wrote:so i did some more research on the iacv and it says that the manual ex motor has 2 wire iacv. the harness that i am using from the d16y7 is a 3 wire. im guessing this is why its throwing the code and i am having idleing problems. how do i fix this?

see if you plugged the vacuum line into your fuel rail.

N2HIFI · Post by **N2HIFI** » Wed Jun 29, 2011 3:50 pm

97slvrhatch;268418 wrote:so i did some more research on the iacv and it says that the manual ex motor has 2 wire iacv. the harness that i am using from the d16y7 is a 3 wire. im guessing this is why its throwing the code and i am having idleing problems. how do i fix this?

There are a cpl write ups on this, so I would search on google but this most likely your issue and and a common problem when doing that swap

Here is a good link with the info you need

http://www.jdmuniverse.com/forums/how-t ... te-up.html

JustRob · Post by **JustRob** » Wed Jun 29, 2011 4:13 pm

97slvrhatch;268418 wrote:so i did some more research on the iacv and it says that the manual ex motor has 2 wire iacv. the harness that i am using from the d16y7 is a 3 wire. im guessing this is why its throwing the code and i am having idleing problems. how do i fix this?

I'm guessing you're using a manual transmission P2P, right? The proper way to fix the issue is to use a manual trans D16Y8 intake manifold that matches your engine. '96-'98 intake manifold for a '96-'98 D16Y8, '99-'00 intake manifold for a '99-'00 D16Y8.

Once you swap on the correct manifold with the 2-Wire IACV, you'll cut the 3-Wire plug off the engine wire harness and replace it with a 2-Wire plug. To give you the proper information on how to do this, I need to know if the wire harness, ECU and car is OBD2A or OBD2B.

When that's finish, plug in the knock sensor and wire in VTEC. Based on what you said, this should clear out all your DTCs.

97slvrhatch · Post by **97slvrhatch** » Wed Jun 29, 2011 5:23 pm

JustRob;268427 wrote:I'm guessing you're using a manual transmission P2P, right? The proper way to fix the issue is to use a manual trans D16Y8 intake manifold that matches your engine. '96-'98 intake manifold for a '96-'98 D16Y8, '99-'00 intake manifold for a '99-'00 D16Y8.

Once you swap on the correct manifold with the 2-Wire IACV, you'll cut the 3-Wire plug off the engine wire harness and replace it with a 2-Wire plug. To give you the proper information on how to do this, I need to know if the wire harness, ECU and car is OBD2A or OBD2B.

When that's finish, plug in the knock sensor and wire in VTEC. Based on what you said, this should clear out all your DTCs.

everything is obd2a the ecu, harness, and the motor. does anybody on here have a manual trans intake or know where to get one fast. this is my dd and i need a car. just for time being could i plug my old ecu in and would that fix my idling problem before i can find another intake? its the stock ecu from the y7 and its also a manual trans(p2e) and that also is obd2a.

97slvrhatch · Post by **97slvrhatch** » Wed Jun 29, 2011 5:25 pm

civicex;268423 wrote:see if you plugged the vacuum line into your fuel rail.

the one that i plugged into the fuel rail is only two wires. could that be my problem?

97slvrhatch · Post by **97slvrhatch** » Wed Jun 29, 2011 5:26 pm

could anybody explain why i need the whole new intake when the sensors are on the throttle body. why couldnt i just get a manual trans throttle body?