92 accord wont pass hydrocarbon emission test

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ok, here's the lowdown:

manual 92 accord with the 2.2L is failing emissions. test showed almost double hydrocarbon than state limit. to go with that, when engine is cold the is a little sputter during any non-granny acceleration (not jerking but you can tell somethings off). sputter decreases as engine warms up. revs drop quickly and sometimes i miss the shift because of it. when warm, revs drop much much slower like its lazy (FYI its my first manual). car has also sat through a winter outside with maybe only one start. i drove the car for about 4 months now, so its not old gas/oil. both have been fresh and i've used premium and it makes a knock so i use regular mostly.

im looking for as many ideas to get this car to run perfect and im willing to do just about anything and try to do it myself.

things already done:

injector cleaners: Guaranteed to Pass (missed by .02 :( ), SeaFoam, ethanol
new PCV valve
new o2 sensor (only has one that i can tell)
cat is new from just before it was stored
new spark plugs gapped to spec
distributor cap/rotor is almost new (not worn, but i cleaned it up with a small brush)
intake/exhaust valve adjustment to .010"/.012" respectively
fresh oil/gas
new radiator/coolant (old one had a hole)


things planned:

new fuel filter
new fuel pressure regulator
refurb injectors (please tell me your experience with refurbs, should i get new?)
replace knocking intake rocker
clean fuel system with acetone
clean oil pan/screen and acetone the oil paths into the topside of the head (i suspect a dirty path killed that rocker)

any other ideas guys?

i think a combination of a leaky injector and clogged filter could be a cause of the sputter and quick drop in rev when cold and slow drop when hot. im just looking for as many ideas as possible.

FYI - while i had the valve cover off, it wasnt all sludgy and black in there, just a golden brown color in most places which doesnt seem bad for an engine that old.

posted by  valvestate

Yeah if it's running rich, check the O2 sensor. Any chance the spark is too advanced?

Giving the engine a birthday is always a good idea.

posted by  Wally

...puts timing light on list of sh1t to buy... should be within spec, it's never been tampered with as far as i know, although if an idiot worked on it, he coulda screwed something up... how would i change the timing without messing with the ecu? twist the distributor housing a little?

what's the procedure to check the o2? voltage check on the sensor output? if so, do you know which pin and the nominal output on idle when warm?

posted by  valvestate

If you haven't given up and taken it to a mechanic, then this should help. The sputtering at idle, slow return to idle when warm, and the high hydrocarbon level leads me to believe you have a vacuum leak. other conditions that would cause high HC emissions include: ignition misfiring (bad plug or wire), incorrect timing, excessivly lean Air/Fuel mixture (could be caused by a vacuum leak), dirty fuel injector(s), low compression, excessive EGR valve dilution, defective valves, guides, or lifters, or defective sensors.

use a vacuum gauge if you have one, if not or if you don't have much vacuum at idle, check all the vacuum lines coming off of the intake manifold from end to end.

Good luck! :thumbs:

posted by  Joe117

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