I'm having a hard time figuring out what might be causing this. I hope someone can help.

92 Accord DX 230k miles when warmed up it "misses" or runs rough when starting out, and especially when in high gear (2k rpm & 30 mph) and you give it light acceleration. This is very noticible up to about 2800 and 40 mph).

Tried these things in this order:
Plugs
Wires
Distributor
Thought it might be a compression problem, had some uneven pressures so I had the valves done at a machine shop.

It seems to be a little better after I did the head, but it might be my imagination.
Thanks...

 

Might be plugged up EGR ports though the RPM seems a touch high for that problem. Usually EGR ports plugged up will cause stumble/lean burn under light throttle around 1700 RPM.

 

You were right on about the RPM, it is closer to 1800 when it starts. BTW, I found a really good way to recreate the problem instead of trying to drive it and recreate the problem.

With the engine warm and while holding the brake, put it in Drive and slowly increase the RPM. It shudders like crazy starting at 1800.

I'm going to try the clogged EGR port suggestion. Too bad I didn't know about this forum a few months ago when I had the valves done and the manifold as sitting there on the bench in the garage!!! Of course I wouldn't have had the thing apart if I would have suspected the ports.

 

Before I get started is there a way to rule out the EGR valve being the problem?

I disconnected the vacuum line to the valve and plugged the hose. That completely elimintated the hestiation and missing. But... as soon as I got to about 1800 the check engine light came on.

Can I assume from this that the valve was working properly and the problem was the plugged ports were forcing all the exhaust gas into one or two cylinders?