Running very rich..

fastsc92

Registered User
My car is running very rich and dumping some dark smoke out the tail pipes. It has no cats and it must be running very rich. I took my stock MAF and cut the bridge out and drilled out the sampling hole. I believe that is why its running rich. I did this because I'm running nitrous and want to be a little safer, but for street use its just lousy to have it smoke whenthe pedal goes to the floor. Is there any way i can fix this for the street and go back to running rich at the track? I have an AFPR and a guage. If i turn down my FPR, does that only turn down the pressure at WOT, or does it turn it down throughout its power band? If thats the case I'll turn down the PSI a little, but I want to make sure it turns the PSI lower at idle and no just WOT. Thanks guys. Or I could jsut get a stock MAF body, cut the bridge out of that and leave the sampling tube alone and swap the two when i go to the track. ANyone have one for cheap??
 
I took my stock MAF and cut the bridge out and drilled out the sampling hole. I believe that is why its running rich.

Yep, that's a start. Modifying a MAF won't guarentee that you richen it up, it will just make it run like crap. You have even lean it out

I did this because I'm running nitrous and want to be a little safer, but for street use its just lousy to have it smoke whenthe pedal goes to the floor. Is there any way i can fix this for the street and go back to running rich at the track?

Did someone actually tell you that modifying the MAF would make it safer?


I have an AFPR and a guage. If i turn down my FPR, does that only turn down the pressure at WOT, or does it turn it down throughout its power band? If thats the case I'll turn down the PSI a little, but I want to make sure it turns the PSI lower at idle and no just WOT.
Changing fuel pressure will not have long term leaning or richening effects. The EEC will learn out whatever you put in, so within a week of raising fuel pressure you car will no longer be lean


Or I could jsut get a stock MAF body, cut the bridge out of that and leave the sampling tube alone and swap the two when i go to the track. ANyone have one for cheap??

again, not somthing I would do. There's no guarentee it's going to even richen your car up.


Your best bet is to get a tuner or a chip programmed for more fuel and timing retard.

Brian
 
well if you drill out the MAF...the computer thinks its running lean because of the added air flow.....so it will richen the fuel mixture. I just want to stop the smoking on the street. The car runs the b@lls, but its just running rich. Is my only choice to get a stock MAF and use that?
 
Your best choice is to take what you got, and get on a dyno with a tuner and get a chip burned that will give you the fuel you want when you are flowing the nitros, and a good mixture when just cruising.

We got 2 full days of cars running on a dyno and getting chips burned by fordchip in Minnesota on Saturday and Sunday. A couple on Monday I think as well. For under $400, you get it tuned perfectly.

The problem with cranking down the fuel pressure is then you won't have the pressure you need at higher rpm's to support the flow of the injectors.
 
well if you drill out the MAF...the computer thinks its running lean because of the added air flow.....so it will richen the fuel mixture

well maybe. That's assuming all of the other stuff you did to the MAF won't disrupt airflow causing turbulence which could actually the meter to think there is less air flowing.
 
i modified a stock ford 70 mm cut out bridge and drilled hole to 15/32 mine runs fine not rich at all +hi flow exhaust
 
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