Hi,

1991 Civic Si with ~150k    

Tonight I went grocery shopping and drove around and let the car warm
up. The car sat parked for around 45 minutes in 30 deg. F weather. I
drove about a quarter mile then and let the car idle as I ran into a
building for 30 seconds.

I don't remember any problem engaing reverse and backing out, but when I
tried to engage 1st the car was not happy. I'll try to explain this the
best I can: It felt like there may have been a problem with the
engagement of the flywheel to the friction disk and pressure plate of
the clutch. I thought maybe I shifted into 3rd instead of first; a
similar feeling. I replaced the clutch and had the flywheel resurfaced
around 10k ago and haven't noticed any problems related to the work so far.

I was able to get moving, but I can't remember exactly what I did. I
might have just reved the engine more than I normally would when
engaging a gear. I remember shifting into 3rd and 4th once I got going
on a longer, open road normally without problems. I pulled over a couple
times to try starting from a stop again, and the problem was seemingly
gone. I got home just fine. I had to move the car around 30 minutes
after getting home. The car started harder than normal, and then the
problem was back when I tried to back out my driveway. The symptom that
seemed like a possible clutch problem now felt more like an engine
stalling. I think the engine is "stumbling when I try to engage a gear.
Maybe it has some problem as soon as it has to torque the wheels.

To summaraize what I'm thinking:

At first I thought it could be a drivetrain problem, but since it went
away for a bit that seems unlikely. I am thinking its an engine problem.
I have a Helm manual and have looked at the troubleshotting charts. I'm
thinking of looking at fuel pressure. The filter is recent, but the pump
is original. The car is generally well maintained (to the best of my
knowledge) by myself. Has anyone ever had a problem like this? I haven;t
really noticed any declining performance; this seemed to come from
nowhere. Thanks for any ideas or advice.

Mark