I have a UK 2001 Mazda 626 1.8 which has been a wonderful workhorse of a car until it recently developed a strange problem. I told the garage about it at the last service but, on collecting the car, was told they couldn't find anything wrong. The problem persist and I'm going to have to sort out taking it back to a garage but wondered if anyone may have any idea what could be causing the following problem.

Drive the car (from cold) 20 or more miles.
Park car, turning engine off.
Leave for 10-15 minutes.
The car will start fine but will not idle. As soon as I remove my foot from the accelerator, the revs just drop to 0 and the engine cuts out. On occasions the amber engine warning light will come on.
After the car has been left for an hour or so it starts fine.

There is no problem once the engine has started and running. I can quite happily stop at lights, etc without any worry of it stalling. If I turn the engine off and then start it again straight away, all is fine. It does seem to need this 10-15 minute period before the problem kicks in.

Any ideas anyone?

 

Sounds like an Idle Air Control Valve sticking after a good heatsoak. Are you able to allow the RPM to drop down to 800-1000 rpm using the throttle pedal or does engine just stall below a certain rpm? Might try having a friend tap lightly on the IAC when it is acting up and see if it will suddenly idle normal.

 

Thanks for that useful information. The engine starts and runs as long as I have my foot on the throttle. Once I remove it then it drops, smoothly, to 0 revs. I have on a couple of occasions had the engine idling at only a few (<100) revs spluttering until it stalled.

Unfortunately my knowledge of cars is somewhat limited Would it be possible to give me an indication of where the IAC valve is and what it may look like or would I be better sourcing a Haynes type manual for the car to locate it?

 

I've located the IAC valve. Returned home from work this evening, left the car 15 minutes. Tried to start it, it wouldn't idle (as expected) and the amber engine warning light was illuminated.

I gave the IAC a solid rap with the handle of my screwdriver and bingo, the car started, idled and the engine warning light went out.

I then went for a 20 minute drive, came back and left the car for another 15 minutes. Tried to start it. It spluttered a bit but started and idled no problem.

I'll keep on trying this and will report back on my findings here in case it is of some use to another frustrated owner at a later date

 

Am glad you found it ok ControlG. Sounds like you found the problem as well. 626 in US market has never had a 1.8 engine so not sure which pic would have worked for you but will post both. First is the 2.0 engine in 2001 626 with IAC mounted on top of the throttle body and second is the 1.8 engine with IAC mounted on the under side of throttle body. Maybe will help someone else to locate.
Please do post back with what you discover as there seem to be a lot of frustrated owners.

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6 months on and until today the problem was still present. The car has been to 3 different garages, all unable to find the fault.

Today, back to the main dealer (their 3rd attempt) and at long last it's fixed.

The problem was caused by a seized EGR Valve. It was removed and left to soak in carburetor cleaner then refitted.

Bingo - problem solved.

 

where is the EGR Valve located?

 

No idea I'm afraid.

The main dealer sorted the problem out for me. Oddly enough was discussing it at work today and a colleague with a Vauxhall had a similar problem except his just stalled once the engine got hot.

His bill was £150 (&0 part + £80 labour). Mine was £9 for the carburetor cleaner.