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air intake (heated vs non-heated) and IAC bypass
#7
ok , it's got good mileage figures, so can't be too sick
the isc hose pinch looks good.
ok your strobe lights like mine, can dial back and see real rpm (that tool is dead accurate,digital , is reasons. good.
the plugs must be gapped to .7mm this old car has weak spark, not till the COPs, (later ) did spark go high energy,
yours is like ours but has the Electric EGR, motor drive EGR< way better than our Vacuum modulated monster.
good.
that 2300 rpm not 1200 to 1500 rpm seems to be all from the IAC< so it must be old and non linear, but does close at 65c so works there,
just opens too far, when open. finding one is not easy.... (cheap)
i think rockauto.com but are expensive.

10 meters away stink.
sounds like its way to rich cold started, maybe the FPR is messed up or stuck closed, but if it was MPG would suffer.
i agree that is a big big stink.... not just random whiff of dead cold cat sink.... as is normal. (till it lights off)

sure we only block isc (sorry, not implying full time ) to test them, only and related's, to see if its a contributor to the high cold idle.
how did you modify the IAC, , really curious that.
its a huge path in the base of TB. to the horn.
any blockage attempts on the IAC would be very hard to do. like go 90% to get a flow reduction

here it is
how'd you do this....
at 19"hg vacuum , huge air flows here. cold.

[Image: 16v_IAC_w1.JPG]

or at the horn end (the huge slot in the TB horn?)


the cold start air is:
IAC + (nothing from ISC ) + air bleed top of TB + TV (zero flow here, all the time at idle)
the bleed screw sets idle dutycycle to 50% (centers it)

also the ISC can leak a bit old.(its rubber ring seat )
ive even tightened it (isc 5mm allen) a hair to cure this leak (i blown in it with lips, feel the leak hose off, key off, and then if it leaks tighten this hex screw. to stop it, just a tad. do not let the spring inside compress....

also the TB top, bleed screw might be way wrong.
if the bleed leaks air all the time to calibrate the duty cycle but if someone unscrewed it CW, and duty is now way off hot. then cold idle will suffer.
hot duty is 50%
if if its way off due to bleed wrong this leakage for sure will mess up the IACs flow, and add to it more than normal (50% duty calibrated)
when cold the ecu keeps the ISC 100% closed, and must not leak.
http://www.fixkick.com
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RE: air intake (heated vs non-heated) and IAC bypass - by fixkick - 04-26-2016, 06:18 AM

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