Car Jerking when Accelerating

[rx4ur7]

Yes Monkmon33, you are correct in that light everything you state is true.

I was just referring to fuel level in tank in stock based applications as being the cause.

In my experience modifications done by many DIYs that are not done with a lot of thought in mind in that overboosting, insufficient fuel delivery and/or proper safeguards being taken usually lead to fuel starvation and resulting engine failure due to detonation.

Whilst properly built and maintained vehicles very rarely do. A bad fuel pump, clogged filter, injector or failure of control system would be one of those. Although blocked filters or injectors can usually be attributed to human error.

BTW-The IMSA and Firehawk cars were stock FD3S so it is a testimony on how well engineered the factory vehicle is when maintained properly.

So actually we agree, not enough fuel NA or turbo will cause the round motor to rattle resulting in $$$ for your local builder.

[powerhouse]

Lets get the monkey on the right banana tree.
1. Run out of gas, NO detonation.
2. Run on lean gas, "Kaboom"

Run out of gas at low RPM . a possible sputter before you stall.
Run out of gas at high RPM. burrrrrrrrrrrrrr if you know what i mean.

[Monkman33]

Originally Posted by powerhouse

Lets get the monkey on the right banana tree.
1. Run out of gas, NO detonation.
2. Run on lean gas, "Kaboom"

Run out of gas at low RPM . a possible sputter before you stall.
Run out of gas at high RPM. burrrrrrrrrrrrrr if you know what i mean.

Problem with your "run out of gas" issue:
You never go from full pressure and proper AFR's to zero fuel within a millisecond. you get air in the lines as the pump runs out of fuel to pressurize the system. As the pressure drops, your injector pulse-widths stay the same. Thus injecting a leaner mixture, which can cause detonation if it gets too lean. Then as the pressure keeps dropping or fluctuating depending on where the remaining fuel in the tank is being moved to (based on the movement of the vehicle) the car will run worse and worse. Again, not enough pressure means less fuel, means leaner AFR's, means higher chance of detonation.

That is the problem with fuel starvation... you never JUST run out.

[Monkman33]

Originally Posted by rx4ur7

Yes Monkman33, you are correct in that light everything you state is true.

I was just referring to fuel level in tank in stock based applications as being the cause.

In my experience modifications done by many DIYs that are not done with a lot of thought in mind in that overboosting, insufficient fuel delivery and/or proper safeguards being taken usually lead to fuel starvation and resulting engine failure due to detonation.

Whilst properly built and maintained vehicles very rarely do. A bad fuel pump, clogged filter, injector or failure of control system would be one of those. Although blocked filters or injectors can usually be attributed to human error.

BTW-The IMSA and Firehawk cars were stock FD3S so it is a testimony on how well engineered the factory vehicle is when maintained properly.

So actually we agree, not enough fuel NA or turbo will cause the round motor to rattle resulting in $$$ for your local builder.

Sounds good to me. :-) As I said before, I believe you have MUCH more actual racing and tuning experience than myself, so I did not intend to discredit you in any way.