missing/sputtering on acceleration

[degenerate1991]

The other day, when sitting in a drive thru, my car, a '91 Accord with a stock F22A1, began missing, as if it were running on three cylinders. It will mostly run normally when Idling/coasting, and intermittently run normally given light acceleration, but upon accelerating will miss/sputter as if it is running on three cylinders. The acceleration is atrocious and the fuel economy has dropped sharply. Upon starting, it will run normally, but after about 30 seconds or so it will begin to show the missing/sputtering symptoms. I am not getting any sort of check engine light, though I have gotten an unexplained (as in, no symptoms) code 43 in the past. I have recently (last 5,000 miles) replaced the oxygen sensor, the distributor is relatively new, and I changed the plugs to no effect. Also, the head gasket has a *slow* leak, but it's had this same leak for over 20,000 miles.

Any ideas? From what I've read, I'm thinking the EGR ports are clogged.

[FranklinWaters]

I saw that you replaced the spark plugs but have you replaced the wires? I know when my car has does this in the past, it was the wires and not just the plugs causing it.

[cloudasc]

Code 43 is almost always caused by the o2 sensor. What brand o2 sensor are you using now? I know a quick way to rule out the o2 sensor, is to unplug it (will turn on your cel), and see if the problems go away.

You can bypass the egr by unhooking the vacuum line from the intake and plug it with a screw and see if the problem goes away (will eventually trip a cel for egr)

[degenerate1991]

The 02 sensor is a Denso, and the wires are relatively new, but not new enough to rule out completely, so I'll keep them on the "list" of things to try. I'll give bypassing the EGR a shot, and if that doesn't work try unplugging the 02 sensor. If anything, I'm curious if having it run in "check engine" mode will fix it, as it did when the 02 sensor failed (When it failed, the car would intermittently stumble *hard* on acceleration, and then run fine when the check engine light kicked on.). Anyhow, it's not tripping codes now, and stopped shortly after I replaced the sensor, but I'll give unplugging it a shot. Running it with the light on will at least get me to work and back until I can fix it (divorced parents, and my dad's the one with the tools; I have but a rudimentary set of them with me).

[90_ACCORD]

you shouldnt have to block off the egr valve. i know a lot of people with cb7's do it but it is not always needed. take it off first and see if there is a build up of carbon in it. i dont think that would cause your issue tho. if anything it should just cause you to fail emissions and maybe have worse fuel economy

[degenerate1991]

Okay...tried unplugging the O2 sensor, and it didn't work. However, I tried fiddling around with the EGR valve, and, if I engaged it by pushing the diaphragm up with my finger, which I assume would have the same effect as pulling a vacuum on it (don't have a vacuum pump), the miss would occur. So, I'm leaning towards cleaning the EGR passages, and I'll see if that works. If that doesn't work, I'll try new plugs and wires (the plugs I put in weren't new, but were know to be good) and go from there, hopefully won't have to.

[wed3k]

just unplug the egr and see if it misses. usually egr is applied when cruising.

inspect your plugs.

[degenerate1991]

seems to be working

Alright, I fixed a vacuum leak, and replaced the PCV valve hose (turns out, it was leaking badly), and put in some brand new plugs/wires; since then, the problem has ceased to reoccur. Thanks to all who posted. Now to replace that head gasket...