For those logging fuel pressure on PL

[trashmechlv]

I just hooked up my fuel psi transducer. Should the reading be steady on PL or will it fluctuate 3-4 psi even at idle? I would expect some jumping around under boost since my boost jumps around a bit. Heres a PL log just driving down road to show what its doing. Thanks

[earlbrown]

Do you have an Accufab regulator?   If so, it's normal for fuel pressure to chatter all over the place.

[trashmechlv]

Its a Bosch adj regulator.  Im running a 320lph pump for e85 and its starting to overpower my stock return line a little. Base psi wont go lower than about 45psi line off. Not sure if that would add to the pressure bouncing around. Was just curious if its normally more of a steady line.

[Steve Wood]

Mine does not bounce and it has an accufab regulator to boot.

Does it smooth out once the injectors open a bit more?  You used the transducer from Innovations whatever?

[trashmechlv]

Ya Steve I bought the transducer from them. Im running car tonight so I will see how it looks at WOT for a while. When car idles the reading on PL data page changes so fast its hard to read.

[Steve Wood]

If you set "smoothing" to heavy, does it even the curve out any?

[trashmechlv]

Im a PL rookie. I will try that today Steve. Thanks

[trashmechlv]

Setting the smoothing to heavy made it MUCH better!

[Steve Wood]

Does not explain why it was jumping but at least it makes it easier to see the average

Steve

[daveismissing]

Wasn't there a discussion somewhere that the new Accufabs use a ball bearing check valve and the older ones something more like a pintle? .
 New ones behaving as per above IIRC

[earlbrown]

If Accufab did a recent design change that would make a lot of sense.   I took a new one apart several months ago and I could not envision how in the world that thing could work right.   It was basically a spring, a steel ball and a 45 degree seat (that wouldn't seal against the ball)