Fuel pressure sensor & E85 sensor locations

[Takid455]

Any design specific location for these? Is it more pick a spot and go?

[Lonnies Performance]

As close to the engine as possible to minimize any lag time from the reading to what the actually engine receives.

[anguilla1980]

I like that answer, makes sense. I've seen others mount the flex-fuel sensor in the trunk, I don't like the idea of fuel lines coming inside the vehicle.

[jasonz28camaro]

Pressure sensor (low pressure) should be towards the rear of the vehicle near the tank. Flex sensor towards the front. Personally I don’t think it matters where the flex sensor goes though. After a few miles (depending on flow amount in tune) it’s all the same mixed fuel after a fill up.

[Lonnies Performance]

The pressure sensor mounted near the tank is an easy way out for the manufacturers.... it is not the best way to provide accurate fuel pressure at the engine. It cannot compensate for line pressure drop if it mounted at the rear of the car.

Also during the time it takes from a flex fuel reading at the tank, you can be running the engine at a 30% fueling error for that time period... not a good thing.
Your fuel trims can adjust & learn temporarily & reset back, but why if you can do it correctly?

[anguilla1980]

When I get my Rick's tank, I plan on having Carl's PWM FP sensor at my tank, then a Holley EFI sensor at my rail. That way his controller can keep a consistent pressure not dealing with pulsing issues and I know the real psi at the rail for tuning and adjusting the PWM controller. I'm also looking at adding a Radium fuel pulse damper at my rail too so I don't have crazy fluctuations in my data log on my Holley. I figured all of that was a good way to go.

Thanks to this thread, I'll be putting my flex-fuel sensor up front.

[andrewb70]

When I get my Rick's tank, I plan on having Carl's PWM FP sensor at my tank, then a Holley EFI sensor at my rail. That way his controller can keep a consistent pressure not dealing with pulsing issues and I know the real psi at the rail for tuning and adjusting the PWM controller. I'm also looking at adding a Radium fuel pulse damper at my rail too so I don't have crazy fluctuations in my data log on my Holley. I figured all of that was a good way to go.

Thanks to this thread, I'll be putting my flex-fuel sensor up front.

Stock LS fuel rails have a damper in the rails. Aftermarket rails tend to be much bigger, which provides the needed damping effect. In my Holley catalogs I rarely see any sort of fuel pressure fluctuation bigger than a tenth or two.

Andrew

[anguilla1980]

Good to know! Thanks

[Takid455]

Compiling inputs from here & manufacturers, as stated, its all over the place. I plan on putting the E85 by the tank & the Low pres sensor by the engine. That way it can adjust for any lossed getting to the engine.
Unless it an E85 oops (putting E85 in an E10 fill up/ tune or vise versa), The E% error can't be that much fluctuation I am thinking.

[OLDFLM]

We put the fuel pressure sensor back by the tank on my Firebird.