rydinturbo

so i have had a random miss at idle ive ben trying to figure out for years now lol. i was playing with the timing nd fuel pressure today nd i noticed wen i turn the key on the fuel pressure will raise instantly to around 35 then bleeds down to around 19 or so. is this normal? i would think the pressure should stay up as long as the keys on? the fuel pump is new i just put in a walbaro 255. is this normal? or is something not right? the car has 24lb injectors, bbk fuel pressure regulator(which i got both used), walbaro 255 fuel pump(was new)

mattdel

Reasonably normal. Drop is a bit low but still fine. As long as it's around 35 when the pump is running @ idle, you're good.

rydinturbo

really, i thought i remembered when i was doin injector drop tests the fuel pressure stayed as long as the key was on. im not rly sure though i forget lol. so no need to look for a bad fpr or anything?

rydinturbo

here is a video of it with the key on and engine on http://s19.photobucket.com/albums/b1...908_180311.mp4
something seems like its not right, my fuel pressure is jumping when i push the gas then it goes down?

mattdel

Perfectly normal, 100% intended design in an EFI return-line system. FPR increases pressure with throttle, normalizes without it.

rydinturbo

i am still on the throttle wen fp is dropping