Ok we have an 04 cobra thats running lean about 4,000 rpm and up. the scaner in drive mode only reads 36 psi of fuel pressure in boost. Im pretty sure it should be 46 psi in boost. the car has an upper pully and idlers on it. off road x pipe, magnaflow cat back, sct tuner. the car ran fine for 4,000 miles and all of a sudden started dying at 5700 rpm. we then put a wide band in it and says that the car was running lean. after the car was tuned it was running 11.6 to 11.8 when in boost and floored. we just changed the fuel pumps and its doing the same thing going above 12.0 around 4,400 it gets alot leaner as it revs more. The pulls are all done in third gear. what are your ideas please help kenny
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04 cobra running lean
- Thread starter sho_92
- Start date
Clogged fuel filter? :shrug:
What is your fuel pump duty cycle when the car starts going lean?
What is your fuel pump duty cycle when the car starts going lean?
Clogged fuel filter? :shrug:
What is your fuel pump duty cycle when the car starts going lean?
+1....what fuel pump(s) do you have in the car?
just put focus pumps in it. started doing the problem with the stock pumps. changed to the focus pumps and still the same thing.
thanks kenny
thanks kenny
where is the fuel pump duty cycle? don't remeber seeing it in the scanner. the pressure does drop to 36 psi in boost. driving around it goes between 37-41 according to the scaner
also changed the fuel filter twice now
add those to the list thanks
Lets break it down. Your car started acting funny with the stock pumps. You changed your pumps to Focus ones and still had the problem. I see that your car was tuned on the dyno and was fine at the time, a/f and all. The only reason your car would suddenly have a "lean" condition is if the fuel isn't getting to the motor as easily as before. You changed the pumps so they are out of the equation. potentially. The only other thing I can think of is a clogged fuel filter or kinked fuel line. Possibly bad FRPS sensor. I would still like to see your fuel pump duty cycle as your car reaches high rpms and a lean condition. Something is blocking your fuel from getting to the engine all of a sudden. You can datalog FPDC with your handheld pretty easily.
Mike
Mike
Car wasn't dyno tuned just picked up a programmer with programe from jdm and put in a wide band to make sure it was ok. IM gonna look into the fuel pressure sensor by putting an auto meter gauge on the rail (that can be seen in the car). after we check the lines for damage. thanks for the help
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