Hi all!

I got a problem with engine startup - when i start it in the morning in cold condition firstly it hits 3K rpm than rpm starts to go down, passes the 750 mark and stalls! It could (but not neccesary) repeat 1 more time but after that when rpm falls from 3K it suddenly stops at random mark 1,5K or 1,2K... but not stalls! Also i have some idle problem because each time i stop at red light on a cross road i see a different (but stable) idle --- sometimes it is normal 750, sometimes 850 or 900 (but no more) RPM...

Any help would be greatly appreciated!

Thanks!

 

Houw Chief

Welcome to the forum.
Im probably not the best guy to answer this but Ill try...

The start up procedure of going to 3000 is a feature programmed into the ECU by Mazda, Its used as a catalyst warm-up.

If you dont have the stock exhaust system anymore it is a very annoying thing to have, What you can do is depress the clutch pedal before you turn the key, atleast thats how I do it on my eurospec car.

Regarding the randomly idle, Have you checked for vaccum leaks, these are 15 year old cars with high underhood temperatures, so the stock rubberhoses is probably hard and maybe cracked, get some silicone ones, they dont harden and they look good
Also try setting the TPS(ThrottlePositioningSensor) to spec.
I cant remember how its done, last time Higgi from the euroforum did it for me while he was at my place.

 

Thanks Kim!

My 7 is an american version is not going to start if you not push the clutch pedal.

I visually checked vacuum lines but they seem to be normal... i think i should simply replace them...

I will look for a good resource on how to set the TPS to spec...

 

You might be able to add another ground to the engine, faulty ground wires have a tendency to plague people.

 

While the engine is cold, startup in 1st gear will passby the AWS (Accelerated Warmup System)

 

Actually, startup in any gear will prevent the 3k warmup, but not the whole AWS. Mine will idle from 1500-2000 while it's still cold.

 

Thanks guys!