Mazda 626 stalls in neutral or park

Have a mazda 626 that runs fine but will stall when put into park or neutral. The rpm will drop down until it stalls. Changed plugs and wires with original equipmnent.

Thanks in advance

The non metered air passing through the cracks (after the MAF Sensor) causes a fuel mixture problem.

The hose is a very common failure, even if you don't see any cracks, wrap it with electrical tape and see if that helps.

Larry R. Webb
Rov-a-tune Auto Repair
Cazenovia, NY http://www.rovatune.com

Hmmm... '99 is newer than I've got a reference for. I "specialize" in the '79-'82 626s, since I've got an '82 (actually, about two and about a half '82s, if you count parts) and all of those years are interchangable.

Do try wrapping (or if you're into spending money, replacing) the ductwork, though. As others have said, the MAF sensor is likely being bypassed by a leak (even if there isn't one you can *SEE*...) in the ducting, and it's a cheap and fairly long-lasting fix. If it is leaking, that ends up giving the computer falsely low data about how much air is actually being sucked in, which in turn dumps faulty data into the stream controlling the fuel injection, which looks at it and says "Oh... not sucking as much air. Give it less fuel", making the mix leaner and leaner after each sample of engine conditions, until finally it hits the point where it can't stay running and dies.

On the '79-'82, when the A/C switch is turned on, not only is the A/C compressor clutch engaged, but a relay tied into a vacuum solenoid (which is in turn connected to a diaphragm that pulls the throttle lever varying amounts depending on amount of vacuum, sorta like cruise control) kicks on at the same time to boost engine revs slightly. If the '99 has a similar system connected to the A/C, that's probably plenty to override the idle routine and keep it running.

Do try the electric tape - even if you use the whole 2 dollar reel. You will be surprised how far this will take you. You can buy dozens of electric tape reels for the same money the dealer will ask for the original part.

Check the air intake hose for cracks. These can be very hard to see (best to remove and inspect) and can cause this problem. If it's bad you can either replace it or cheap out like I did and wrap a lot of electrical tape around it.

I suggest you also check the PCV valve hose ( or any other vacuum hose you can find). I just changed my PCV valve. I tried running idle the engine with the hose off: the engine slows down gradually untill it stops completely.
This description is similar to your symptom.

I also had a 1988 626 before . Once the air bellow had a small leak, causing erratic idling, and engine hesitation when starting from stop untill reached second gear speed (manual tranny). I used the electric tape method to seal the leak - lasted for years !

That's it exactly! The hose had a split on the underside about 2" long. I don't think the tape will hold forever though. The engine moves quite a bit when I go from Reverse to Drive. Hope the dealer can get one for me.
Else I'm gonna need a boatload of 3M electrical tape...

Thanks a bunch quys. I'll down an extra brew for ya'.