My car is running lean at WOT

[JJhirsch]

1994 Mustang GT

My dyno sheet showed a straight 14 air/fuel from 3500 to 5500RPM. The timing is set at 12degrees and i just noticed at WOT 4000-5500RPM i can hear little pinging.

What i think is causing it is my 73mm Pro-m MAF and i dont have my stock one. Is there something that i can do without getting a tune? Maybe a adjustable fuel pressure regulator?


Thanks JJ

 

[RichV]

You need to provide some more info before you get help.

What's the combo? Stock with a 73mm MAF? Why?

 

[JJhirsch]

You need to provide some more info before you get help.

What's the combo? Stock with a 73mm MAF? Why?

It is with a bbk cold air intake because stock size MAF is 60mm? This Pro M is for better air flow. The owner before me put a JET chip in. Should I uninstall the Jet chip?

 

[Addermk2]

Should I uninstall the Jet chip?

Yes.

 

[RichV]

Not sure on the Jet chip, ditch it. What #s did you make on the dyno?

Can you put the stock MAF back in? The restriction on these motors is not the MAF when all stock.

 

[Addermk2]

Stock maf is 70mm.

 

[slow90coupe]

Shoot 14 is not a bad AFR. That's much better than my car was stock. When I hooked up my wideband to my car (it had nothing but exhaust at this time) it showed 16.5 afr, and the car was driven for thousands of miles like that. It's never a bad idea to get a tune though.

 

[Addermk2]

14 at wot is terrible.

 

[Monsterbishi]

Any leaner than 13.2:1 at WOT and you're heading into trouble territory.

Also, keep in mind that there are plenty of times when detonation/pre-ignition is not audible to the human ear.

 

[Musturd]

You guys stayed in it when the air fuel was at 14-1 smh .... Some people shouldn't tune or dyno cars ... Like adder said ditch that chip ...