Misfiring....

after $400 of tests done by a whingdong mechanic he THINKS, its the MAF Sensor... could this be true? Its really weird how its running. I just skips a beat every now and then, and its complete random when it happens, when you first start it, its horrible but it usually smooths out a bit after its hot. What do you guys think?

Thanks a bunch! I'm sick of this mechanic... he doesn't even have the computer or whatever to test the maf, or can I do that with say a voltage meter? Thanks again!

 

Hello there,
I had a Runner a few months ago in the shop doing exactly what you describe here. I went through EVERYTHING I could think of. I have seen MAF sensors go bad on these (usually causes stumbling during acceleration and sometimes Fuel Trim diagnostic codes). The Runner I had ended up having a cracked spark plug of all things!:pat: Just goes to show that is sometimes pays to look at the basics first.

 

Clean the MAF/IAT module. Its just behind the air filter. The MAF/IAT is notoriously bad about getting dirty and giving the ECU bad data long before the ECU throws a code and lights the Check engine light, usually with a P0171 or P0172 code.

Clean by spraying contact cleaner on the temperature bulb and down into the MAF hot wire. You can also clean this out with warm water, dish soap and a toothbrush as you GENTLY brush away the gunk.

Dry throughly before reinstalling.