Hi,
I have just fitted a K&N Typhoon induction system and I now seem to be getting Idle droop when coming to a stand still at traffic lights etc. All appears to be running fine when on the move, but when I stop the revs drop to 400 RPM but do recover after a few seconds.
These symptoms where apparent before fitting the induction kit but not as bad. I am guessing that it is probably the idle control valve (or what ever Mazda call it) or maybe just a dirty throttle body butterfly. I guess it could also be the MAF but I am not sure.
Is there a guide to cleaning these items for a 2001 Mk2 1.8?? I have found a guide for cleaning the throttle body on a Mk1 (probably the same for the Mk2) throttle body in the FAQ’s but couldn’t find anything on the MAF or Idle control valve. I guess you can use Carb cleaner but I wasn’t sure if this is saf on the MAF.
Can anyone help?
Thanks in Advance
Si
I’d also like to know how to clean the MAF…
Use a xylene-based cleaner on the throttle body; some older carb cleaners are benzene based (will strip a coating off the butterfly); there can will indicate whats in it.
Do not use carb cleaner on the MAF; either track down a specific MAF cleaner, or use a switch cleaner aerosol (isoprpoyl alcohol). Only spray it, don’t attempt to rub the wire.
I would also suggest making sure that all the intake connects are tight; idle problems can often be due to air leaks.
You may also need to reset the base idle.
Setting base idle link & link to the pin layout. I’d try this first before messing with anything else.
Sorry to hijack but i’ve reset the base idle as per instructions, however the screw is fully in and it still sits above 1000rpm… any suggestions?
throttle cable too tight so not allowing the butterfly to fully close. A stuck open IAC valve maybe… Disconnect the IAC valve plug with the engine runing and see if the idle speed alters. An air leak can cause a higher idle speed too.
Will check the throttle cable tomorrow morning, where is the IAC valve?
Edit - just found this article which seems to mirror my problem -
http://forum.miata.net/vb/archive/index.php/t-127302.html
Just noticed you have a 1.6; so a flapper AFM not hot wire MAF. Disregard previous precautions; just clean with regular intake cleaner.
As for high idle; its a common problem on the 1.6. It might be the idle speed control valve; gummed up or faulty. Could try cleaning it (you’ll need a new rubber seal and paper gasket from Mazda). You might have an air leak; with the engine running, squirt intake cleaner at the joints, and listen for the engine stuttering. If it does, you have an air leak.
ISC valve diagnosis and repair (excellent)
http://www.miata.net/garage/isc.html
The other possibility is the sealing paint on the throttle body butterfly has been damaged by the incorrect cleaner. I know someone who managed to restore this with enamel model paint.
Another suggestion is that the green topped water termister on the back of the cylinder head has gone bad; this “tells” the ECU if the engine has warmed up. If not, its on a cold start cycle/
Lastly, some have found corroded ECU connections to be the culprit.
I spent 3 years trying to figure it out, but never did. Even a Mazda dealer didn’t know (or wasn’t bothered, as it was a Roadster).
Hi,
Thanks for all the replies. It would seem that the car just needed a long run. When doing the mod I disconnected the battery so it might have just taken some time for the ECU to re-learn the engine etc. I will keep an eye on it as the throttle body butterfly was pretty black so would only beneift from a clean.
Cheers
Si
Diagnostics bring up error code 9 which i believe is the green plug down the back of engine…being pretty cheap i’ll try this first!!
Thanks for your help!