air fuel mixture
 

My car runs really rich in fuel and not sure why? i have checked vacum lines, switched out the mass air. someone told me its because im not running cats and that throws off the o2 sensors. they have also been changed. any ideas? oh it also has the typical rough idle. i have heard of a fix for that but cannot remember?

is your maf clocked correctly?

How could it be cats if the HEGO's are before the cats?

Whats your timing and fuel pressure set at? Need some more info on your setup if possible thumb:

Also how many miles are on the injectors

I'm running a fresh rebuilt, 30 over, gt 40 heads and intake. b303 cam with roller rokers 1.6. everything else is stock. not sure what the maf is clocked at? also not sure what the timing is at, a garage set the timing and fuel pressure for me. im running a adjustable fuel reg but like i said a garage set it up for me. the injectors have probably 200 kms on them. i just put the motor in last weekend and now its running way too hot! 210 hwy driving and 220-230 in town and thats like 5 mins of in town driving. I tried switching out the fan with dual electrics but made no diff. im running a new 2 core rad. is this maybe not sufficiant enough to cool it down? im gonna try replacing the thermo next.

I would try and find out what your timing is at cuz if its advanced to much it will make the car run hot. Also put a failsafe 180 degree t-stat in it just to be safe thumb:

i just put a fail safe in today just incase. Ill find out what the timing is on mon! any ideas what it should be at? would too advanced of timing give you poor fuel mileage because its pretty bad compared to the way it used to be! lol

Well depending on your mods, 12 degrees should be good. Good luck thumb:

hey thanks! i retarded the timing without a light and just went by the sound and its soooo much better! it runs better and much cooler. thanks alot for saving my stang from a match! lol