Prelude code 12 (EGR) related to stalling problem ?

Spec: '93 Prelude - Jap spec (100k miles) 2.3 vtec.

My dealer didn't want my business when I told him my Prelude is an import.
Since their competitor closed down, there's no other Honda dealers within 50
miles.

Problem:
Past 6 months, car stalls intermittently (average 3 times a month).
Stalls when yielding at junction, traffic lights, round-about etc. All when
off the gas - car is warm. Car always restarts first time.

Other info (dont know if any of these are relevant)
I've had an ECU code 12 warning for a year - dealer doesnt want to
bother diagnosing.
I get a cat (red console light) warning when cold - it flickers and then
fades out after a few mins.
Ignition switch seems a little dodgy, rarely when I take the key out, it
beeps to warn me I left my keys in. I have to put the key back in and out
again to stop the beeping.


I don't think I have the expertise or equipment to diagnose this myself, but
I can probably get the dealer to replace specific parts.
My feeling is that if it were an electrical problem (such as main relay or
ignition switch), it would not only stall when approaching a stop. What is
so special about approaching a stop ? Clutch disengages, RPM drops to idle,
still breeze coming into the radiator (as opposed to when stopped at idle),
speed sensor shows positive reading (an input to the ECU ?).

I've heard the following suggestions:

Replace main relay - Symptoms are normally not restarting when car is warm
(at service station etc). This never happens.
Replace fuel filter - I never have a problem with fuel delivery when on
the gas or when shifting gears - would this mean fuel filter is ok ? Also,
it never stalls when stopped at idle.
O2 sensor - Would this cause other problems and be more persistent ? Also,
would this normally show up as a trouble code ?
Plugs - Haven't replaced, but car seems to run ok, plugs look clean.
Wires - Just about within limits (15k ohms longest wire, other wires have
less resistance).
Vacuum problem - Could the stalling and EGR trouble code be realted, or
would the EGR value just run open (or closed) thus disabling EGR ?

I can throw a bit of money at it, but want to limit my exposure - i.e. don't
want to give the dealer a blank cheque - dealer doesnt seem interested in
troubleshooting anyway.
Any ideas / suggestions - I'm desperate here !!! It's a bit dangerous
stalling at a junction when you can lose some steering & brakes !

Cheers,
Chris.

 

Sorry to hear about your troubles. Sadly enough, I can't offer much
advice except I can tell you that it's NOT the main relay. I have a
'92 Lude with a relay that's total shit. Well, it works (ie. the car
starts) when it's not too hot. However, even on the hottest days, I'll
never stall at a light or where ever. What I can do however, is
provide you with a link to the mechanic's manual for a '93 Prelude.

http://www.icelord.net/honda/repair/

Enjoy :-D Hope she gets well soon.

 

I had the pretty same problem(but not a Honda) it was idle air contorl
valve went bad,hope this help.

 

You can try taking your car to your local auto parts store. Many of
them will check your car for ECU codes. From what I could find, a code
12 is the EGR circuit. You could have a bad EGR valve or a build up of
deposites in the manifold system. Stalling or rough idle can be caused
by this. It also sounds like you need to replace your ignition switch.
Failure on Hondas is common.

 

Put 500m of injector cleaner in the fuel tank.

Hasn't stalled since - with nearly 1000 miles done. Idle seems smoother too.

Thanks for all the advice guys...

Chris.