All,

'93 Prelude; We swapped from stock USDM H23 to H22A JDM VTEC. All works well except that its running way to rich, soot coming from exhaust, mileage crappy, smell of gas in oil (washing cylinder walls) and the idle oscillates between 750-2000 rpm out of gear and settles down while in gear.

We can get the idle steady if we disconnect the MAP sensor vacuum line and blow into it while starting, then leave it disconnected. Gas mileage picks up on highway driving.

Also the P13 ECU which came with the H22 throws a MAP sensor proble code and also a MAP sensor out-of-range code. When we put the old P13 in for test it seems to be happy with the MAP sensor.

Question Does the '93 USDM H22 use a 1.5 Bar Map and does the JDM H22A use a 2 Bar MAP? Would this cause the problem or are we barking up the wrong tree?

Thanks in advance!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dehrmantraut &raquo;</TD></TR><TR><TD CLASS="quote"> the idle oscillates between 750-2000 rpm out of gear and settles down while in gear
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not sure about the rest but my h23a has the same problem with the idle. its probably the iac valve (intake air control)? you might be able to clean it out to fix it or i've heard the springs inside it go out, then you would need a new one.