That PID is indeed correct. On vehicles without a fuel rail temperature sensor present and calibrated in, it defaults to 60*F.
For the slope/offset table on these vehicles, it substitutes the ACT value for the FRT for the offset lookup, and if ACT is malfunctioning it automatically sets the multipliers to 1.0.
There's no incorrect PID here. It is indeed correct. The only issue is the assumption that FRT is still being used as the lookup.
If its not broke, just give it time.
Originally Posted by Steven@HPTuners
Well dang, I wish someone in support had told me that!
This is the first I have heard about ACT being directly substituted to drive the offset and slope modifier tables.
They just kept telling me that these rail temp based tables either weren't being used at all, or were using the channel locked at 60*F. I submitted test logs that proved both of these to be wrong.
Thank you for the insight!
Is this the same for all or most Ford calibrations? I thought my 2018 F150 had a proper value and it fluctuated. But the Whipple Cal looks to be locked on the GT350. Values in the table seem to go much higher than necessary if one considers it simply uses ACT in the later example.
On a heat soaked start does it just use cranking fuel until fuel flow cools the rails? Doesn?t seem like a very precise alternative. I will log my idle and warmup trims vs ACT to see if it allows me to get them more dialed in.
gen 3 coyotes(18+) have a fuel pressure and temperature sensor the driver side fuel rail, this means the ECM finally does know the pressure and temperature of the fuel in the rails.
Oh man, I wish there was a path to pop in an 18+ sensor and drive injector modifier tables.
I have a fuel temp unreliable parameter, it logs as no. I do not have ACT, but I do have Manifold Charge Temp. Is that what it uses?
This is a Whipple cal for the gt350
MCT is the “IAT” in the manifold itself. The Ford SC OS that Whipple uses has the dual temp sensors for IAT. One in the MAF, one in the Manifold.
It would be great to know, once the MCT switch is flipped on, which tables are redirected to IAT2 / manifold, and which remain linked to the MAF sensor IAT.
MCT Heatsoaks after its warm, doesn't come down in temp much or all that quickly even with cooler IAT's so I would not guess it would be a really accurate data point to use for rail temp modeling but who knows. Whipple cal has IAT, IAT2, and MCT. The more I log however the more I think its still just a very minor issue with my car. Primary Air / fuel modeling is just off too far just for rail temp. I reached out to someone for some assistance.
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