grabbem88

ok i started the beast up havn't drove in a month.anyways went and checked my gauge.
if you blip the throttle it does jump to 42psi,but if you are part throttling it 15-2000k it drops to 30psi,and then i
hit it real hardit flew back up to 42psi......i quit after getting peppered with ice,and water BLAH!
whoever has a fuel gauge on there's tell me what it does.

roundman

I've got the Aeromotive adjustable regulator on mine and I set it with the pump on, engine off to 50 psi. with the engine running and vacuum hose connected this gives me 44 psi at WOT and about 42 psi idling. fuel pumps are very sensitive to current and voltage so I would double check the wiring going to your pump to make sure it's big enough to carry the amp load it needs to be getting to keep the pressure up when you go WOT. sounds like the pump ain't large enough to pump enought to keep the pressure up when you are at WOT with the 24#/hr injectors but not 100% sure this is the problem. don't think the MSD has anything to do with this part of it either. the fuel pressure regulator tries to maintain a constant pressure differential across the injectors at varying engine speeds by sensing vacuum (engine load) and increasing pressure as the vacuum goes down which it does as you open the throttle. 0 vacuum is where you get the highest pressure reading so that's why the instructions for mine said to set it with the engine off and only the pump on. you could also have a partially plugged filter sock on the pump or a bad fuel fitler also, so I would check/replace these too to make sure they aren't the cause of your problem. and check all the lines to make sure they don't have any big dents or kinks anywhere which could also be restricting the fuel flow throught them.

grabbem88

set it with just the key on?
do you have stock fuel rails on?just wondering,cause someone told me that aeromotive bleeds off when shut off the key.
i'm thinking the person never changed out my pump....said he did..

roundman

yeah, you have to have the key on so the fuel pump comes on you know!
I've got the stock rails and 19# innectors too and yes, the pressure will bleed off over time but that's not a problem for me as I usually turn the key on and wait until I hear the fuel pump stop before I hit the starter. I read something somewhere that says the ECU and fuel pump relay work together and if the ECU don't sense the engine running within a second or two after the key is turned on, it turns off the fuel pump.

grabbem88

i did what you said....i'm confused i turn the key on and my gauge goes to 42psi fo a split second then
falls back to 25psi is that right????

nemethjames1

no thats not right... somethin is still wrong..... pump maybe? maybe your injectors are supposed to be set up a lil higher then 40?

grabbem88

so it's supposed to hold???
no my afr was 13.1 from 3k to end so i'm good

nemethjames1

so the afr is good but it still says psi is low?

vfast

you could have an injector leaking

grabbem88

so how can i find out?besides we checked it before it got to the injectors.