man i have a serious problem with my car, it has a very eratic idle and i dont know what it is can you help me out plz!!! im goin crazy..



93 civic
d16y8

 

ok, does it drift from a few hudred k to 1500 or so or is it real shaky and hard?

 

it just drifts fom a few k to 1500 rpms.... could it be an o2 sensor on the exhaust or a intake manifold sensor??

 

Rule out the simple things first...

- Vacuum leaks?
- Throttle cable too tight; doesn't allow throttle to close completely?
- Gunk in the throttle body, especially around where the throttle plate closes against the bore?
- Air in your cooling system?

 

no.no.and no well ill check out the cooling system but i found out im throwing two engine codes....variable valve timing and control pressure switch(vtec seems to be working ok) oxygen sensor heater? what the hell is that! (is the heater in the o2 sensor??)

 

There's an oil-pressure switch associated with the VTEC system. If oil pressure isn't high enough it won't engage VTEC. That one could be caused by wiring, or maybe your oil pressure actually is low.

Yes, your O2 sensor has a built-in heater. Could be bad, or could be a wiring problem. Check resistance between the 2 same-color (black?) wires of the sensor. It should be 15 to 40 ohms.

But I don't think either of those things will cause your idle surging. How about checking/cleaning your IAC & FIT valves.

 

ok IAC and FIT what exactly are those and where on the intake mani are they?? and is a p28 ecu a obd1 or obd2?) that is what im using in my 93 civic lx 4-dr with the y8 swap but i have a d15b7 intake mani im thinking my problem is within these two things (p28 and b7 mani)

 

vtec should have nothing to do with it as it is kickin from op and 4k + . sounds like to me is a throttle cable too tight or a vaccumm leak associated with pcv or brake booster.

 

I don't have a Civic, but...
Usually the IACV is on the back side of the intake manifold, looks like a little motor.
Usually the FITV is on the bottom of the throttle body, has a coolant hose.

P28 doesn't say which OBD it is. There's probably P28s that existed for OBD-1 & OBD-2 depending on what year the P28 is made for.

 

95 civic