Problem 2 - Fuel System

[Chritaka]

A few details about the car:

Whipple HO @ 10 psi
47k miles on car, 36k with Whipple installed
Stock fuel rails. Fuel sensor installed into crossover fuel line on passenger's side.
Fuel filter replaced last summer, about 10k miles ago.
AM Nexus Gauges

#2 The fuel system appears to get heat soaked...? During the hot summers in Texas, the fuel pressure appears to slowly increase after driving a bit, stop/turn off the engine, crank it back up, drive a bit, stop/turn off the engine, etc, etc. After each stop/restart the FP seems to climb about 2-3 psi. The car appears slightly sluggish when this starts to occur. It ONLY does this in the summer time and the FP slowly climbs up to 30-35 Ibs after multiple stops/restarts. During the winter the car FP stays around 20-22 Ibs no matter how many stops/restarts. I had the fuel filter replaced last summer about 15k miles ago, that helped slightly, but it still increased slightly after each stop/restart. The car has already started doing this again and we've only seen a few 95 degree days.

I have no ideas on this one as the fuel filter should still be fine... Suggestions?

 

[lito]

Commanded fuel pressure depends of ACT so in warmer weather it will command higher pressure.

 

[Chritaka]

Commanded fuel pressure depends of ACT so in warmer weather it will command higher pressure.

Thanks for the response, not sure I understand your meaning though... "depends of ACT"? I get that higher temps cause higher pressure, but my point is this isn't a highly customized setup and is a typical Whipple HO configuration that is daily driven. It shouldn't be getting this hot that it would cause the pressure to climb after each stop/restart. I haven't been able to find any other posts of this same type of issue. With the pressure getting up to nearly 40 psi in the heat isnt normal. My local shop thought it was the fuel filter and said if it kept climbing to bring it back in, so that would seem to say it isn't normal. just looking for other ideas that may be a quick fix or things to check before I have to take into the shop to troubleshoot it. Could it be I need better fuel rails, possible issue with the Auto Meter FP sensor? Could it be the location of the sensor?

 

[69Mach1-409]

I've never seen my FP climb a noticeable amount after multiple start stops in the heat. Granted we don't get as hot as your summers, but still..

I do notice that she'll feel a bit sluggish after multiple start, stops.. but I always attributed it to the high IAT's due to heat soak, from the stop / starting with no time to cool back down.

 

[lito]

Fuel high pressure has nothing to do with anything on the filter. The people that told you that doesn't know a thing about this cars.

ACT is aircharge temperature, it raises the pressure with temp to avoid fuel vapor locking.

This is a complicated electronic returnless system, there are tables in the calibration to manage fuel pressure depending on different conditions.

In essence, you have a sensor in the rail that tells the PCM the actual pressure differential and it compares with the commanded pressure and acts in consecuence taking into account any modifier that is set into the calibration.

In a word, this is totally normal.