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evap code PO0443
#2
as easy as loose gas cap.!
33 is ok, keep in mine, if it cycles perfectly with 12v, its ok, 3 ohms will not make much difference. s
shorted coil , bad, open coil bad, about 30 ohms, and works with power applied and not,
lets review 443 in the fsm
"incorrect purge flow". the lt-green/yellow wired, solenoid. ( it says leaking vent hose, and that means gas cap too.,)
http://www.acksfaq.com/96-FSM-v2-6E3-A-part4-pdf.htm
page 132
a tech, would check the cap first, if was loose, bingo.
if cap does not leak. then do a take pressure leak down tests, if that fails fix that first. vast places to leak.
then do the hard tests.
the diag is done only at idle. never driving, only parked. or at idle hot.
and can take 20 mins to clear after a reset, or never on and empty tank 15% min.
page 133 is the test set.
no kidding evap is way complex.
3 chapters in the book here are the next 2. EVAP1 and 2
http://www.acksfaq.com/96-FSM-v2-6e3-c3-a-pdf.htm
http://www.acksfaq.com/96-FSM-v2-6e3-c3-b-pdf.htm

im not sure if you have EVAP 1 or 2 system , some 96 have only EVAP 1 and is vastly more simple, just count solenoids. 1 sol, is early..

im hoping its EVAP 1
the 2nd chapter, page c3a page 1, tells who the ECU finds the failure, and is KEY. see text "
Quote: the ECU can also check..
.".


1: hot idle. about 19inches plenum vacuum at the ready. beiind that VSV (closed) then..
2: the ecu cycles the purge valve
3: and then it looks at the ISC duty cycle and at the fuel injection times.
when they open the valve , air flows from the EVAP tank up the carbon chamber and to this point and from the tank past the diaphram regulator back aft.
if the iSC duty don't close down (less idle) and the injections dont rise. then it fails. (this is what the ECU does to do the actual 443 test)

a hand vacuum pump can test the regulator back aft via the front canister fitting and you can test the canister at its fitting. for leak down rate.
it must leak. if not its blocked closed some how.
and you can test the VSV 100 % just by applying 12v. or let the ecu open it. and see it suck air with the hose off on output side of VSV.

when the Purge VSV opens, extra air (and fumes) is allowed in to the plenum ,this causes a lean condition (Unmetered MAF air), the ecu sees that and increases the injections, RPM rise over 800 the ECU then sees that and drops the ISC more closed. and 800 rpm happens again.
when the VSV close ,the reverse.
that is how the EVAP 1 works. very simple,

hope that helps. EVAP2, if you have that, its a near endless story. but do tell !

keep in mind the gas cap has a vacuum breaker so of the diaphram valve at the tank line sticks open , the vacuum can suck too much.
that is why they have you check the freeze frame. to see if its
1: too much flow or not enough.
http://www.fixkick.com
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Messages In This Thread
evap code PO0443 - by dynabill - 07-17-2013, 10:12 AM
RE: evap code PO0443 - by fixkick - 07-19-2013, 08:07 AM
RE: evap code PO0443 - by dynabill - 07-19-2013, 12:07 PM
RE: evap code PO0443 - by fixkick - 07-19-2013, 11:50 PM
RE: evap code PO0443 - by dynabill - 07-20-2013, 09:08 AM
RE: evap code PO0443 - by fixkick - 07-20-2013, 01:11 PM
RE: evap code PO0443 - by dynabill - 07-20-2013, 02:17 PM
RE: evap code PO0443 - by fixkick - 07-21-2013, 10:58 AM
RE: evap code PO0443 - by dynabill - 07-21-2013, 10:58 PM
RE: evap code PO0443 - by fixkick - 07-22-2013, 12:15 PM
RE: evap code PO0443 - by dynabill - 07-22-2013, 12:31 PM
RE: evap code PO0443 - by fixkick - 07-22-2013, 12:55 PM
RE: evap code PO0443 - by dynabill - 07-23-2013, 10:44 AM
RE: evap code PO0443 - by fixkick - 07-27-2013, 11:47 AM
RE: evap code PO0443 - by dynabill - 07-30-2013, 10:36 AM
RE: evap code PO0443 - by fixkick - 07-30-2013, 12:52 PM

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