1999 PROTEGE 1.8L Barely idols throwing p0171 & P0303. have checked everything! Did notice with the air cleaner open when I place my hand before the mass air flow sensor, restricting air flow the idol picks up and runs normal. Any ideas????

Thanks Jeff

 

Read: https://www.mazdaforum.com/forum/maz...g%C3%A9-31136/

Many of same items are still useful on 99

 

good reading, Thanks! Still curious about when I place my hand ahead of the mass air flow sensor, restricting air flow the idol picks up and runs normal.

 

If you do that you are choking the engine. The computer figures: hell, raise the idle speed or I die!!!

Do all the cleaning of the TB, IAC Valve and MAF sensor. Check for vacuum leaks, in particular the air intake hose.

 

 

Thanks to you both for taking the time. Is there any merit to unhooking the battery for 10+ minutes to allow for things to reset? If I do that will I need to relearn it the idol speed?

Jeff

 

You must do these will doing repairs to engine. After disconnecting battery press brake pedal a few times to make sure all other electricity released. After all cleaning stuff is dry and re-installed, re-connect battery and let idle for 5-10 mins before driving, re-learning has begun.

 

Yeah, I'd probably say give resetting the ECU a shot by disconnecting the battery for a bit, then reconnecting it.

 

Ok so it has been auto repair week at my home. After bringing the Mazda int the warm garage and letting the motor warm up. I again was barely idling, I sprayed near the injectors/intake gasket. The idle picked up and began to run normal for a few moments. If I'm not mistaken on the 1.8L that means it is in need of a new intake gasket? I have searched high & low and am not finding a good instruction or video for this repair. So I have a few questions;
Which gaskets should I be replacing other than the intake?
Are there o-rings on the injectors? And should those be replaced also?
Do I need to drain the coolant for this job?
How much time should this repair need?
Any other things I should consider while doing this?

Thanks again, Jeff

 

I think you found the problem. However, I never had to do this job so I can't help with the details. I suggest you get a Haynes Manual. Parts stores carry them.