adammilad

i have recently swapped a d16y8 in my 94 civic vx i kept the car obd 1 with the vx harness. i was using the original p07 computer but it didnt give me the full potential of the motor so i went and got a p28 out of a del sol. the p28 gave me a much higher redline and a stronger vtec but there was a problem below vtec the car would barely spudder along any ideas on what could be causing this.

HiProfile

Probably because you are using the wrong base timing. The y8 has a base timing of 12*, but the p28 (z6) is mapped for a 16* motor. Add 4-6 degrees of timing with the dizzy, and see if it works better. There's also the possibility that the injectors could be dirty, the pump not giving a full 42psi, etc.

dohcVTECeg2

are you using a 4 wire o2

adammilad

i kept the 4 wire O2 sensor that was on the original motor and yes the CEL is on. how can i correct the timming issue?what is a dizzy.

coneheadsracing

while the timing may be true..... i've been running y8's and y'7's on p28's for a few years now. What distributor are you using?

adammilad

me and my buddy took the y8 distrubutor appart and combined it with the old wirring from the vx motor. do you have any input on this.

coneheadsracing

slightly confused. Well, i was always using obd I wiring harness with my setup. But i used both a obd II and an obd I distributor, but all i did was swap plugs that hook up to the distributor. Could be an issue though, i'd keep the distributors all the same, and just use one or the other. You can use the obd II distributor, but i'd just use the vx one. I don't know, personaly i've used more then a few distributors laying around from various different obd engines. I haven't had any issues, but thats not to say you wouldn't. But i would start with the changes you made to the distributor. Something does seem weird, specialy since its smooth in v-tec.

adammilad

switching the plugs is pretty much what we did. my friend knew more about this than i did. when you use the p28 on your y8 did you change the timming.

adammilad

i am using ngk iridiums and i have replaced them recently while they where under warranty. i noticed that they didnt have much of a deposit on them so i think it might not be getting enough fuel .

coneheadsracing

I didn't touch my timing. Set everything to top dead center. I really don't know. Try using everything from the vx distributor once, see if that changes anything. ARe tehre any other symptoms, like using oil, or antifreeze. Does it smoke at all?

v4lu3s

so did you rewire teh 5 wire stock o2 on the vx to work with teh 4 wire stock o2 for all other civic engines?

adammilad

okay i opened the hood and yes it is a 5 wire O2 sensor. should i convert to the 4 wire O2 sensor and if i do how do i do that? do you guys know how i can get the CEL codes off of my car myself or do i need to pay someone to do it.?

v4lu3s

well yes you DO need to rewire to use a 4 wire o2 sensor. civic wiring diagram will show you pinotus and wire colors on waht to move.

sorry i am not more help, but i do this kind of work for a living and dont have my wiring diagrams at home anymore. but anyway until you fix that at least you will not be able to get he check engine light to go off.