My car is a Mazda 2001 Protege, recently it has begun to choke and die while in drive and stopped, like when stopped at a traffic light. Idling in park or neutral is fine, reverse is fine. I have recently replaced air filter, spark plugs, wires, and coils. I use an engine/injector cleaner when I fill up. It still gets 31mpg and has almost 200K miles . Why does it not idle in drive like it does in neutral? I appeal to the experts here.
Did you check your transmission fluid?
Fuel injected vehicles generally have something called and idle control valve or idle air control (not sure what Mazda calls it). This is usually mounted to the throttle body and controls the amount of air allowed to bypass the throttle blade when it’s shut (idling) to control the idle. Over time it can get gunked up and clogged or can stop working. Often a good cleaning with spraw throttle body cleaner is all it needs.
Possible temp workaround, until you get it fixed… Try turning on the a/c before coming to a stop, that should kick up the idle enough to keep it going.
Does the thing sort of stumble and sputter and die, or just flat out die as soon as you come to a stop or put it in drive? I assume you would have mentioned if the check engine light were on?
If it’s the latter, that sounds an awful lot like a torque converter clutch problem. The torque convertor is what allows slippage between the engine and transmission when you’re idling in gear, and the TCC is a gizmo that basically locks the engine to the transmission when you’re driving at higher speeds, thus improving your gas mileage. If the thing sticks, the car can’t idle in gear so it’s like having a stick shift with no clutch.
TCC problems were an epidemic on 80’s and 90’s GM products, but other cars occasionally have problems with them too. I honestly don’t know Mazdas that well, but it could be a possibility. At least with the GM TCC’s, it’s actually a pretty cheap repair as far as transmission repairs go, or you could even just disconnect the thing and accept slightly lower gas mileage.
If it’s stumbling and dieing, I’d agree with the others on an idle control valve issue, or it could simply be a vacuum leak-- the computer can compensate for even fairly large leaks at speed, but can have trouble at idle.
Thanks for the replies. Transmission fluid is good. At a stop, it’s OK for about 4 seconds, then starts sputtering and dies. I’ve been managing by shifting into neutral at stops. One good thing is that it has “shift on the fly”.
I’m going to start with air leak, seeing as there’s a big crack in the air intake hose. I found it while looking for the IAC valve, may as well clean that while I’ve got things apart. I will have to pick up parts tomorrow, no one is open today. Thanks again for all the help, guys. Back to roasting the duck, come on over if you want.
Pretty good bet you’ve found the problem. Wrap it with duct tape for a temporary fix (and to confirm that’s what it is). The reliable repair is a new air intake duct. Fairly easy if you DIY.
My dad’s truck was acting up at idle and it ended up being a hole in a vacuum hose. My Jeep was doing the same thing once and it turned out to be a throttle position sensor.