4KQ Smog Problems-Update, still stumped

JShadzi at aol.com JShadzi at aol.com
Sat Jan 5 17:40:41 EST 2002


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Ok, I am really stumped on this one, remember, this car is at 1900ppm in the
HC, Gross Poluter is 240- here is what I have done/checked to date:

-Plugs/wires/cap/rotor
-Swap ign. distributor with one known to be working
-Compression Check, 150 across all cylinders
-Pulled injectors, look almost new, soft/pliable seals still on, perfect
spray patterns at all elevations of plunger
-Timing at 6BTDC
-Crank, cam, dist all in alignment
-CO set at 10mA and it fluctuates between 8 and 11mA
-New O2 sensor, visual inspection of cat
-Water temp sensor changed with known working one
-Throttle switches tested and working.
-All vacuum lines changed, no vacuum leaks
-Vacuum advance canister NOT working, but plugged with RTV to prevent leak.

The car is very driveable, accelerates well, frankly if it wasn't for the
smog numbers its a great running car.  It does have a slight miss, though,
and I think this is at the root of the problem.

Interesting to note, when I pull one plug wire at idle there is hardly any
change in the idle, and the engine accelerates well with the throttle
blipped, and it does this regardless of which plug wire is pulled, almost as
if this miss moves between cylinders.  I am becoming convinced that its an
electrical problem, not a fuel problem, the only thing I have not changed in
the ignition system is the ECU and the Coil...I have a working ECU, maybe I
will swap it and test that.  Any idea what could cause such a good running
car to fail the HC test by a factor of almost 20??

TIA,
Javad





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