Car appears to be running rich..smell gas...have results of scantool scan >
07-26-2002, 06:14 PM
#1
Race Director
Thread Starter
Car appears to be running rich..smell gas...have results of scantool scan >
My 1993 Corvette with hotcam kit installed, and Ed Wright chip appears to run rich.
There is a smell of gas at idle from the exhaust. Also I only get about 15 MPG in city driving, and maybe only 19 to 20 on the highway.
O2 sensors are 6 months old (Napa style)
I hooked up my scan tool and block learn numbers always come in below 128 at like 101-114 range. O2 sensors fluctuate constantly between high and low mV's as they should. All sensors except one appear normal...Air intake temperature sensor is always too high (like 115 F after a half hour on a 85F day)....Right side, and left side Block learn numbers' are normally both always lower than the 128 that I ahve seen on other cars.
The block learn numbers are constantly fluctuating too. Sometimes I'll see one side will make it to 128, but then the other will be at like 101.
No trouble codes are set either.
Integrator numbers are normally closer to 128, but they are still lower.
If I remove a spark plug, the insulator looks almost white (almost lean?), but I will admit I have only looked at the front two spark plugs on the passenger side of the engine since they are easiest to get too.
Some people say maybe you have a leak before the sensor....but honestly where would it be? I have had the cats off before and am sure they mated back up to the stock exhaust manifold? i do see an EGR valve unit on the driver side manifold? Can that be sticking or doing something to hurt the oxygen sensor's readings....
Anybody have any ideas. Help would be appreciated!
There is a smell of gas at idle from the exhaust. Also I only get about 15 MPG in city driving, and maybe only 19 to 20 on the highway.
O2 sensors are 6 months old (Napa style)
I hooked up my scan tool and block learn numbers always come in below 128 at like 101-114 range. O2 sensors fluctuate constantly between high and low mV's as they should. All sensors except one appear normal...Air intake temperature sensor is always too high (like 115 F after a half hour on a 85F day)....Right side, and left side Block learn numbers' are normally both always lower than the 128 that I ahve seen on other cars.
The block learn numbers are constantly fluctuating too. Sometimes I'll see one side will make it to 128, but then the other will be at like 101.
No trouble codes are set either.
Integrator numbers are normally closer to 128, but they are still lower.
If I remove a spark plug, the insulator looks almost white (almost lean?), but I will admit I have only looked at the front two spark plugs on the passenger side of the engine since they are easiest to get too.
Some people say maybe you have a leak before the sensor....but honestly where would it be? I have had the cats off before and am sure they mated back up to the stock exhaust manifold? i do see an EGR valve unit on the driver side manifold? Can that be sticking or doing something to hurt the oxygen sensor's readings....
Anybody have any ideas. Help would be appreciated!
07-27-2002, 10:03 AM
#2
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Location: hialeah fl florida
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Re: Car appears to be running rich..smell gas...have results of scantool scan > (dizwiz24)
I have a silmilar problem with the blm i have a zz9 cam in my 92 i will get diff reading from left and right like 120 140 what help for me is with the scanner look at the IAC co unt it should be around 20 or 30 i began closing the idle ajusting screw and number began to get closer together smell was almost gone, like you i get no black smoke and the plugs look bone white
07-27-2002, 05:54 PM
#3
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Thread Starter
Re: Car appears to be running rich..smell gas...have results of scantool scan > (cesar)
the IAC count is something I have totally overlooked.
My service manual says a value of 0 is fully closed, while 140 is fully opened.
Maybe my car is only running rich at idle....once I drive it and have the throttle blades open, it runs fine.
Where is this adjustment screw at?
BTW, the service manual does not recommend tampering with the adjustment screw, but then again my car is not stock.
My service manual says a value of 0 is fully closed, while 140 is fully opened.
Maybe my car is only running rich at idle....once I drive it and have the throttle blades open, it runs fine.
Where is this adjustment screw at?
BTW, the service manual does not recommend tampering with the adjustment screw, but then again my car is not stock.
