88306stang

I have an 88 mustang. the motor is a 306. i just rebuilt the whole motor because it was a nitrous motor and it spit out pretty much all of he gaskets. now i have it back together and i'm having the same problem i did before i fixed everything. the car is running fat and keeps loading up. i heard that if the intake has an elbow in it if you rotate the maf it will help. not in my case. i got different results but all leading to the same question. why cant i stand behind my car without crying my eyes out. fuel pressure is at 38 with vaccum off of it and low 30's with vacum on. still running rich. no idea why.

92hatchLX

Was there a custom tune done? What was done to the motor before you rebuilt it? What's done to it now?

88306stang

the motor is a 306 it has 24lb injectors. the cam uknown afr heads edelbrock performer rpm intake. computer tune i'm not sure. the maf is a 75mm supposedly tuned for the injectors. first thing i did was check the fuel pressure because i noticed that it had an adjustable regulator i set the base to 38 with vacumm on it we're looking at low 30's.

92hatchLX

Wonder if it was tuned for the nitrous or something, definentally sounds like it's running rich. Have you cleaned the MAF yet? Replaced oxygen sensors?

88306stang

the guy who did my motor said that the o2's should be fine i'm going to throw stock 19's in the car and a 19 lb maf to see if i get a better mixture. if the fuel mixture is still off then we can assume O2's

Joel5.0

Suggestion.....why don't you ask the one that's doing all the settings on the A/F mixture, check what it has to tell you in the form of failure codes...... http://www.troublecodes.net/Ford/ ......don't assume, use the tool at hand, it's free......the ECM.