How many miles, and have you replaced the fuel filter?

 

I had the same problem with my old car... a POS Mazda where everything broke on it... but either way it turned out to be a vacuum leak which killed any type of idle stability and would also kill the car because the idle would drop so low.

 

it has 150k on it..i dunno if the fuel filter has been changed..she just bought it about 1 month ago

 

well, without knowing it's maintanance history it's hard to say. Don't touch the idle control. It could be your TPS Sensor, fuel filter, fuel pressure regulator, EGR valve, or it could be electronic. test the EGR valve by lifting the diaphram(sic?), if it moves freely then it's good, if it does not then it is stuck and needs to be replaced. Is it throwing any codes? If not then more than likely it's not your fuel pressure regulator. When the TPS sensor goes bad it tends to give the motor an irregular idle rather than stalling. It could also be electrical. first check all the hoses, then replace the fuel filter (it will need replacing anyway and it will give you a starting point for maintanance since she just bought the car. lastly, get a haynes or some type of manual for her car so you can trouble shoot. More than likely it's something simple though. But to really figure it out I need more info on the cars specifics and maintanance history.

 

so far, i have replaced: plugs, wires, dist cap, oil, filter, ign coil, pcv valve, air filter. i just cleaned the aic valve and that didnt work either. i have now figured out that it only stalls in gear and when the car is warm. it wont stall when its cold or in park.

 

how do you test for a vacume leak?

 

Yea my car does that right now. I jsut replaced the throttle body cause my TPS went to s***. but the car still dies when the engine is cold, so im replacing the fast idle valve. Hopefully thats gonna fix the problem.

 

a lot of the time, it's something with the tranny... With autos, they get touchy... Try replacing the tranny fluid, checking all connections on the tranny, and then just look over all the little **** you never think about...

 

my g/f had that samething happen on her 98 civic (auto), she would be driving down the road the it would just stall. I looked online for recalls and sure enough the was one for (auto) engines that would just stall for no reason. There was something in the ignition system (where the key gose) that was causeing to many volts and was over heating it. Honda fix it for free. jhope this helps

 

Is it throwing a CEL?

Check EVERYTHING under the hood that you can. Check all lines/hoses connected to the intake system. Sounds like a vacuum leak to me. If it begins to stall after the brake is applied, the car seems to be confused as to how much fuel it needs to maintain idle. There are a lot of sensors on Hondas. It could be any of them. Check the visual stuff before having to spend a dime.