So my truck has much more throttle response at lower operating temps and if its been fully warmed up and then shut off for say 45 min/hour it seems to be even more responsive. When reflashed via a PPE tuner or EFI live tune it ( the problem ) disapears for a week or so and then returns. Any idea what could cause this ? Thanks in advance for any help...:beer
more responsive at lower operating temps ?
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My truck seems the same. Off idle response seems better when I first start it after it's set for hours. I have no idea why.
Is it possible that it is as simple as a density issue?
Example/reasoning: before the engine and engine compartment and transmission warm up, the boost tubes and intercooler are at ambient temp(and its much colder out now so my theroy would be more pronounced) also, the fuel and fuel lines are at ambient temp. So with the temps being so much lower in winter, would it be reasonable to assume that the air and fuel are reaching the cylinder in denser therefore greater quantity? This would result in slightly more power and an enhanced throttle response, would it not? And only til the truck warmed up to normal operating temps, and the then the air and fuel density would become less as it got warmer.
Just a thought please dont flame me out over it.
Example/reasoning: before the engine and engine compartment and transmission warm up, the boost tubes and intercooler are at ambient temp(and its much colder out now so my theroy would be more pronounced) also, the fuel and fuel lines are at ambient temp. So with the temps being so much lower in winter, would it be reasonable to assume that the air and fuel are reaching the cylinder in denser therefore greater quantity? This would result in slightly more power and an enhanced throttle response, would it not? And only til the truck warmed up to normal operating temps, and the then the air and fuel density would become less as it got warmer.
Just a thought please dont flame me out over it.
look at the iat and ect pilot timing modifiers and do a log of those temps as well as where you feel more responsive and adjust the timing modifiers accordingly.
This maybe a silly question but can the iat and ect pilot timing modifiers change themselves ? what would cause it ? I have had this problem with 3 different tunes. Once the truck is reflashed its fine for a week or two then detunes itself.... and mileage decreases. And no its not just happening in the winter
I don't believe so. Occams Razor, go with the option that involves the least assumptions. I would venture to guess that there is some sort of external variable not involving the tuning of the truck.
I think this makes a lot of sense and in my opinion would have to be a factor. That dense air is compensated with additional fuel. This is part of the reason mpg drops so bad with a cold engine. In airplanes, you manually lean out the fuel to compensate for a loss of air density. I think this is partly the computer compensating for this automatically.
Just wanted to add I know this doesn't explain why this problem would go away for a couple weeks with a re-flash, just saying it makes sense.
Denser air and pilot timing have a large effect. Altering your pilot timing can reduce fuel consumption at idle (and cruise, to a lesser degree), and change responsiveness.
I've never seen a truck tune change, and from a technical standpoint, it should not be possible. I would also look for external variables.
I've never seen a truck tune change, and from a technical standpoint, it should not be possible. I would also look for external variables.
Can a sensor be off enough to cause the mentioned problems and not set the CEL ? which sensor, IAT ? MAF ?