Lean revs when cold!
Thread Starter
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
Lean revs when cold!
Hello, I'm posting this here because there is hardly any traffic over in Scan & Tune.
I have a 1985 Corvette with the following mods: Mini Ram, Flat tappet ZZ409 cam, Hedman Longtube 1 5/8" headers, 58 MM throttle body, Cat Delete, AIR Delete, EGR Delete, Dynomax Ultra Flo mufflers, Timing set at 10* BTDC, Descreened MAF sensor, air filter lid cut, K&N Air filter, MSD 8.5mm ignition wires, MSD HEI coil, Heated O2 sensor conversion, AFR Gauge w/ Wideband O2 sensor, 3.75 gears, Speedometer calibrator, Throttle body coolant bypass, G2 adapter and a 27SF512 chip.
Essentially what is happening is, at -4* C - 8* C, or 24.8* F - 46.4*F, or maybe just for a short time running at a little above 24.8* F, the car will go super lean when revving, 22.4:1 AFR, and it won't rev up, if I hold the throttle at WOT, it stays at 22.4:1 and then stalls occasionally. The idle AFR at this temperature is around 14.1:1, which is where I've been trying to get it since I'm using 10% ethanol gas.
Does anyone know if there is a table to adjust for this or something in the tune? You can recommend a 165 or the computer above that tables, even though this is an 870. I'll try to find a similar tune.
Or is a mechanical problem? Is the gas inside my injectors freezing?
Please help, I've been trying to get all the problems straightened out in the tune with this car, and I've come pretty close with lots of success from the help of others on this forum. Thanks a lot!
I have a 1985 Corvette with the following mods: Mini Ram, Flat tappet ZZ409 cam, Hedman Longtube 1 5/8" headers, 58 MM throttle body, Cat Delete, AIR Delete, EGR Delete, Dynomax Ultra Flo mufflers, Timing set at 10* BTDC, Descreened MAF sensor, air filter lid cut, K&N Air filter, MSD 8.5mm ignition wires, MSD HEI coil, Heated O2 sensor conversion, AFR Gauge w/ Wideband O2 sensor, 3.75 gears, Speedometer calibrator, Throttle body coolant bypass, G2 adapter and a 27SF512 chip.
Essentially what is happening is, at -4* C - 8* C, or 24.8* F - 46.4*F, or maybe just for a short time running at a little above 24.8* F, the car will go super lean when revving, 22.4:1 AFR, and it won't rev up, if I hold the throttle at WOT, it stays at 22.4:1 and then stalls occasionally. The idle AFR at this temperature is around 14.1:1, which is where I've been trying to get it since I'm using 10% ethanol gas.
Does anyone know if there is a table to adjust for this or something in the tune? You can recommend a 165 or the computer above that tables, even though this is an 870. I'll try to find a similar tune.
Or is a mechanical problem? Is the gas inside my injectors freezing?
Please help, I've been trying to get all the problems straightened out in the tune with this car, and I've come pretty close with lots of success from the help of others on this forum. Thanks a lot!
