7mpg stock FC turbo help
03-03-17, 09:36 PM
#1
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7mpg stock FC turbo help
Sup fellas. Don't know if this is the right place to post since I never had this problem. So since I had the FC It has been running rich as hell, wideband gauge marks 10.6 idle and it's stead up to 6k rpm it goes as low as 8.9. removed the his f con ECU and left the stock one. Still the same. I'm getting about 6-7mpg. It's a pretty much stock motor with a street port, stock Injectors purple tops, greedy top mount, knights sports hybrid turbo, 3in down pipe to stock exhaust. Fuel pump is from a FD, it's a 88 s4. What should I check, spark plugs are new. With NGK wires, car drives good, just the exhaust smells like nothing but gas.
03-03-17, 10:19 PM
#3
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^^ if you want to check the O2 sensor there is a port you can plug a voltmeter, and or LED into, and watch it, work, or not
03-03-17, 10:36 PM
#4
i doubt the O2 sensor is a cause, it works in such a narrow range that it would only be affected a very small amount of the time.
most likely causes:
a faulty AFM
high fuel pressure/rewired fuel pump
oversize injectors
sticky semi clogged injectors
faulty ECT sensor
or some sort of hack to the engine controls that the owner hasn't found yet.
the fact it has a hybrid turbo and is still running leads me to believe it isn't running stock injectors, or someone fiddled with the airflow meter internally and reclocked it. fixing this issue may wind up being a bad idea, you might be wiser to invest in a standalone EMS instead, it will save you gas in the longrun.
most likely causes:
a faulty AFM
high fuel pressure/rewired fuel pump
oversize injectors
sticky semi clogged injectors
faulty ECT sensor
or some sort of hack to the engine controls that the owner hasn't found yet.
the fact it has a hybrid turbo and is still running leads me to believe it isn't running stock injectors, or someone fiddled with the airflow meter internally and reclocked it. fixing this issue may wind up being a bad idea, you might be wiser to invest in a standalone EMS instead, it will save you gas in the longrun.
Last edited by RotaryEvolution; 03-03-17 at 10:41 PM.
03-04-17, 08:51 AM
#5
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Well I'm assuming they are the 550cc sensor injectors, they look like another set I have from a J spec S5 motor. The resistor box has 5 wires from it and it's in the lower part by the air meter? Then yes I have that too
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03-04-17, 12:47 PM
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03-21-17, 11:45 PM
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Sup guys. Sorry been busy with life lol. Soo I been fiddling with the car, recirculated the bov, checked for vacuum leaks, bypassed the resistor pack, new o2 Sensor, found out the factory a/f mixture sensor is bad. Checked the injectors and they are the factory 550c and the item number is there, made by denso. How can I check if my Maf was messed with?
03-27-17, 10:55 AM
#11
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Bump. Changed the Maf nothing.. found out I got a S5 primary fuel rail, also replaced the water temp sensor and nothing. Also my a/f ratio stays the same as when it's super cold in the morning. Shouldnt it lean out a bit after it's warm up?
03-30-17, 10:13 AM
#15
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Sup guys. Sorry been busy with life lol. Soo I been fiddling with the car, recirculated the bov, checked for vacuum leaks, bypassed the resistor pack, new o2 Sensor, found out the factory a/f mixture sensor is bad. Checked the injectors and they are the factory 550c and the item number is there, made by denso. How can I check if my Maf was messed with?
03-30-17, 03:13 PM
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03-30-17, 03:15 PM
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04-07-17, 01:00 AM
#19
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thats right! i was told the same about the air temp wiring, ill check it and hope its good, thanks
10-18-17, 08:51 PM
#24
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Check your fuel line pressure.... nevermind, overlooked some posts. So you were leaking gas under the hood? That's scary haha.
Last edited by Rotary Alkymist; 10-18-17 at 08:56 PM.