Well, then I wouldn't use those regulators. I've never had that problem with those regulators before. One of the purposes of the FPR is to prevent the fuel from flowing back to the tank when the key is off, and if you're losing pressure, then your regulator is not doing it's job.

As far as the vacuum goes, 14" of vacuum leaking in two minutes isn't that bad, but it's still a vacuum leak.

Take care,
~Chris

about a year ago all the manifactures of the billet alumn reguars where having probelms becasue they used 2 diffren metal that expanded diffrenly or something amount those lines..i clearly rember bbk being one and MAC was making one but they pulled it because theres was doing it also..

my Kirban is the best AFR i have ever owned(had 4 diffren ones)it holds like i said like a champ..20psi after 2 days:D ..so far i have had this same one on an all motor 5.0, then a dry sprayed 5.0, and now my 2.3 pushing close to 20#'s of boost..still works awsome..cant say enuff good things

silver_pilate,

If you get a chance, could you put a vacuum pump on your FPR and see if it holds vacuum, or if it behaves like mine. I suspect it has something to do with the way these things are designed. I have my Paxton that I never sent back. I'm going to disassemble it and see how it works.

any one have any other ideas on what to look at for this dam hesitation

Why don't you start by giving us a list of your mods, when you first noticed this, and what was the last mod you did before this started happening.

Check your PCV valve and EGR valve.

pcv valve is good and my egr is not hook up. i also noticed today when i was on the high way my temp got up to 210 after giving it some gas and then it came back down when i was just cursing and in city stop in go the temp was right at 190 any ideas i think the car might be running lean and i have a new 3 core radiator and 180 thermostat that are just a few mouths old any ides

i pulled some codes i got with the key on engine off 67,81,82,84,85 engine running i got 33,41,91 i have removed the ac and all emissions stuff so that why i got a lot of those codes but 41 is a stand out lean how could i be lean im running 48 psi vac off with 19# i have a set of 24# should i put them on and see what happens or should i bump the pressure up to like 50psi or will this kill the injectors

Hypertech
 

I don't have that problem with my hypertech adjustable fuel pressure regulator. Mine holds fuel pressure just like the stock one. Remind me never to buy bbk stuff.

Mountain Main

Like I said earlier, your regulator is supposed to maintain pressure when the key is off. You said yours doesn't. If a stock regulator does maintain pressure, then I would suspect your regulator. It all fits.

Take care,
~Chris