i posted a while back about how my truck had its days when itd run like a raped ape and when it would run like total dog ****... and still the stupid little bog on the 1-2 shift at part throttle sometimes...so since my fuel pump has a bad sending unit and im doing a 1.5 body i figured hey itd be a great time to do the fuel pump now ya know? so what kind of walbro would suit my application? im a 4.8, ive got LT headers, offroad y-pipe, 3in intermediate pipe to a moroso spiral flow race muff, e-fans, 4in CAI, descreened MAF, taylor and E3 ignition setup a custom tune and a couple other little things im leavin out that i cant remember lol...i will be going procharged and possible head/cam swap later too...so ive been told walbro 270 for now or is it me or does that sound too big for my application? also if its not the fuel pump thats causing these symtoms and its the injectors, what injectors are good and what flow rate should i use?? ive seafoamed my truck, used inj. cleaner and nothin keeps this bogg away. not that it matters my motors backed up by a mildly built L60E and will be getting a set of 488 gears, im also looking into a new intake due to mine seal is starting to get moist

thanks for your help

tj

 

well first off from what i can gather. it wouldnt hurt you to go ahead and rock a 255, they are relatively cheap. you can look for a changeout through magnacharger who sells a pretty much direct swap walbro 255. but if you have a little mechanical sense and some imagination u can put one in yourself with the right type of hose.

as for injectors thats kinda up to you. right now i am running a fully bolted 5.3 on 10psi with SVO 42lb green tops. on a stock pump at 60psi fuel pressure and everything is gravy till about 5500 rpm then my pump falls off so im changing mine soon too.

people will say overkill your fuel system and sure you can but if you get injectors too big with nothing to support them you are looking at a tuning nightmare. just take into consideration what you have planned and build from there. i went with 42s because they were cheap and available and i could tune them for my fully bolted 5.3 before the procharger. and now they work just fine too. i see about 60% duty cycle at 5500. but my truck is strange it handles things way differently than others iv read about or seen.

 

thanks for the help man i appreciate it, ill prob just get the walbro n fab up somethin to work. as for stock injectors what psi are they? and what would be comfortable to have with the mods i have now or that would work for both worlds without a tuning issue...as for injectors and fuel pump i hope these both help my starvation issue

 

yeah im pretty sure the factory injectors are rated at 24 lbs/hr at out fuel pressure which is around 58 psi. when it comes to just bolt ons stock injectors can handle pretty much anything bolt on wise. when you get into cams, headwork, forced induction be ready to bump them up

when you do bump them up it really depends on how far your gonna go. if your gonna run like 9 to 10 psi off the bat and plan on more just throw 60lbers on. if your gonna stay at 9 or lower just rock some 42lb injectors.

 

alright thanks for the advice man haha, i figured whatever whats goin on now with the fuel related issue...i should prob just replace the injectors and FP so it doesnt leave me stranded sometime ya know? as for the procharger when it happens...i think im gonna run prob a max of 12, i think the max for the stock bottom end on these LS's are 18lbs?

 

Do yourself a favor and ditch those E3 spark plugs.

 

just curious whys that? my truck likes em way better than the old ngk platinums that were in it