'88 Honda Accord LX rough idle problem

The car starts fine. Once it warms up, if the transmission is put into gear
with brake on, the idle will drop to ~250 RPM and the engine makes a bunch
of metallic pings before it picks back up and runs at a rough ~750-900 RPM,
still idling. I also get a rougher idle if I turn the heater fan up to max.
The car also acts really logey from a standstill.

The problem doesn't occur if it's already idling ok in gear and I swap it,
say from reverse to forward or vice-versa. Also, car seems to idle better
in reverse (?!)

Any thoughts? My mechanic thought the carb needed rebuilding and asked how
much money I wanted to throw at the car. I haven't looked at the fuel
filters yet, but want to know if it is worth worrying about or just letting
the car go.

Thanks,

-Chris

 

Chris the pinging is usually water in the fuel system.
Goto wallmart, get an stp fuel carburator, and fuel cleaner, put them in
your gas tank and then fillup on gas. There is another fuel cleaner to stop
your car from smoking and rough idling. If that doesn't work, look into
getting a tuneup!
I know a good, honest mechanic, he has a passion for what he does and is old
school. He knows all the tricks, so if you need to look into that. Let me
know I will give you his name and number!

 

Gas definitely was part of the problem. I filled it up this morning, and
improvement has shown up already.

Car still stalls after initial warmup when first put into gear, but much
better than it was - it was stalling at the first drop in RPM during warmup.
I'll look into the fuel cleaners.

-Chris