FP Keeps Changing

[Paul Clark]

FP is different everytime I start it. It keeps changing - sometimes up, and sometimes down. Any idea why?
This is at idle.
Thanks.

 

[REEDOG]

How much does it vary? My Accufab unit is really sensitive to temperature. When the engine is cold pressure will be a little higher than when it's hot. The problem is worse the lower the static pressure I run. At higher static pressures it makes no difference at all. No way to solve that problem that I can see, possibly reducing flow resistance downstream of the regulator will minimize the effect of temperature.

 

[Paul Clark]

Mine's an Accufab also.
Had it set at 42. Tonight it was almost at 50 (cold start)
Pressure is pressure. Why should temp matter - and if it does, what good is the regulator? Do you have to pop the hood and check it several times everyday depending upon what the temp is?
Hope not! I live in Iowa and the temp is never consistent - like my car.
(Don't like the weather? -- Wait 5 minutes and it will change)
Thanks

 

[UNGN]

Vacuum Leak?

When you notice it change, unplug the vacuum hose and see what the reading is. See if it changes line off. If it doesn't, its more likely a vacuum problem vs. a FPR problem.

 

[Paul Clark]

Thanks for the tip, but I can always see the change + or - with the line on, and that reading always changes (goes up) when I take the line off - if that makes any sense.
It just doesn't seem to want to hold at any preset adjustment.
Have set the IAC and TPS numerous times, as it would sometimes rev up at start and then slowly die.
New downpipe, turbo, injectors and chip since this started happening, if that helps.
Demonic possesion, maybe?
Thanks

 

[87GNcospg]

my accufab fpr must be demonicly possesed also. temperature seems to effect it a couple of psi and recently after a WOT blast my fuel psi will drop below its 39 line on to sometimes 35 then slowly get back to 39. not sure why.