Just got off the phone with my tuner, and was told that the car pulls great upto 4,500 rpms then it leans out real bad. The pumps and injectors are flowing great. Has anyone seen anything like this or have any ideas?
Leaning out at high RPM's
- Thread starter mystangs
- Start date
Well my first guess @ your power level that you are pegging your MAF. But i see in your sig you have an SCT MAF. Are you sure you arent maxing out the pumps? Did he datalog it? If so what is the Fuel pump duty cycle, and also the MAF voltage.
Dave
Dave
The duty percent on the pumps is 80% and the MAF is 4.5 I think?
Do you know what the duty cycle on the injectors was and how much Fuel Pressure he is commanding in the tune?
Also are those #s SAE or STD?
Also are those #s SAE or STD?
They are STD, I am not sure about what he is commanding in the tune, I did see about 40-42 on my fuel pressure gauge.
I am not sure what the duty cycle is on the injectors either. He did say they looked good and they were well within their duty cycle.
He also talked to Superchips and they really have no idea either.
I am not sure what the duty cycle is on the injectors either. He did say they looked good and they were well within their duty cycle.
He also talked to Superchips and they really have no idea either.
I would say that if you tuner can't tune your car as it sits then you need to find another tuner.
well geez why didn't I think of that?
Hey Chris, I heard you were having problems with the car. Did you guys try calling Dave for advise? Hope you find the problem soon...
Congrats again on the new addition to the family....:beer:
Congrats again on the new addition to the family....:beer:
how bad is really bad?
anywhere between 13 and 15. It never really dips below mid 12's
Yeah we talked to Dave and none of us can figure this thing out.
I appreciate it, It is fun but the lack of sleep is killing me. I will bring pictures next meeting, if not the real thing.
ttt
Check the pressure drop accross injectors and pump duty cycle again. If these are not you problems, the maf is being pegged..and at that power level I am pretty much sure that is the problem. You can tune around it (band aid it) but thats not the proper fix. Get a SCT MAF or MAF Extender.
Someone's data is not correct or the tune is off
Someone's data is not correct or the tune is off
If those are the stock injectors, (I don't see any in your sig), you may be running out of injector.
The same is true for the pumps. Consider going to bigger pumps.
The stock fuel system is good for about 525 HP, and you're right there.
Did the tuner modify the appropriate values when the SCT MAF was installed?
Several areas must be changed.
Dana
The same is true for the pumps. Consider going to bigger pumps.
The stock fuel system is good for about 525 HP, and you're right there.
Did the tuner modify the appropriate values when the SCT MAF was installed?
Several areas must be changed.
Dana
Yeah he tuned it for the SCT MAF, It ran great for alittle bit and then started stalling. We got that taken care of and no matter what gets changed the A/F will not come down.
? clogged fuel filter? That would be real easy.
It is worth a shot. Going to check that today.
How are you verifying the MAF voltage? This is exactly what my car was doing on the dyno when I put my 2.93 pulley on. I was pegging my MAF at 5500 RPMs and it just took a steady climb to 14:1 by 6200 RPMs. I was using my MAFterburner to adjust my A/F ratios due to the design of the in the fender CAI squeezing unmetered air past my MAF sensor and leaning out my A/F ratios. When I put a smaller pulley on the amount of air sneaking past due to the curve in the pipe was much higher. I adjusted so much with my MAFterburner that it "appeared" I had pegged my MAF sensor voltage (even though in reality it was around 4.8 or so) to my computer. I replaced my DenseCharger with a K&N FIPK and zero'd out my MAFterburner adjustment and it got me down to 4.8v On my MAF sensor at 6500 RPMs. Now I stay at a steady 12:1 and dip into the high 11's on the top end - just how I like it.
HTH,
Dan
HTH,
Dan
My tuner is datalogging the MAF Voltage and it is reading fine. The fuel filter was not clogged we are still chasing gremlins.
ttt
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