Nissan 370Z Forum - View Single Post - Rough Start

optiontrader · 09-18-2010, 02:35 PM

I've heard of engines being somewhat difficult to start after 10-15 minutes (like at a gas station), but not after 2-3 hours.

My Honda (del Sol - modified ECU) would exhibit this 10-15 min issue, and it turned out replacing the coolant temperature sensor and adjusting the cold start fuel compensation helped out a lot (but not 100%). My theory was the sensor read good at the extremes, but in between as it cooled down (the 10-15 min range), it would send the wrong temp reading to the ECU, which would incorrectly lean out/richen the fuel mixture upon start up.

But after 2-3 hours? Doesn't seem likely, though I've noticed there is A LOT of stored heat in the VQ37 engine and compartment after the car turns off. I've noticed oil temps still up there after the car's been stopped for an hour.

09-18-2010, 02:35 PM	#7 (permalink)
optiontrader Track Member Join Date: Jul 2010 Location: Smog Hell, SoCal Posts: 595 Drives: 40th Rep Power: 16	I've heard of engines being somewhat difficult to start after 10-15 minutes (like at a gas station), but not after 2-3 hours. My Honda (del Sol - modified ECU) would exhibit this 10-15 min issue, and it turned out replacing the coolant temperature sensor and adjusting the cold start fuel compensation helped out a lot (but not 100%). My theory was the sensor read good at the extremes, but in between as it cooled down (the 10-15 min range), it would send the wrong temp reading to the ECU, which would incorrectly lean out/richen the fuel mixture upon start up. But after 2-3 hours? Doesn't seem likely, though I've noticed there is A LOT of stored heat in the VQ37 engine and compartment after the car turns off. I've noticed oil temps still up there after the car's been stopped for an hour. __________________ 40th Anniversary Z - 3M Paint Protection Film, CA Legal Tint! (70/40)