Hey guys, I'm in a bit of a pickle. I've searched and searched and havent found the right information I need. I recently put a cam in my truck (comp265 212/218 558 563 on a 115) it also has full boltons. Right before I did the swap, My truck was running great! really smooth and really powerful. Since getting the new motor together and in, something is wrong. At WOT full load, my truck bucks and hiccups and cuts out. No codes are being set but something is very very wrong. My FP at idle is 49psi, at wot no load it goes to 59 psi. If I remove the vaccum line it jumps to 59-60psi. This indicates that my FPR is ok does it not? I put a new acdelco pump in it roughly 20K miles ago w/ the new pigtail and about a week ago I replaced the filter (I double checked the flow arrow on the filter!). The plugs are new NGK tr55s and the plug wires are stock replacements from napa with about 20k miles as well. What do I do? I don't know where to start or what to look for. It is not a flexfuel truck and I have a wheatley tune on 91 octane. Truck runs good at 1/2 throttle and below under normal load but WOT is when I feel it "cut out". Can anyone steer me into the right direction as far as what to check next?

Sorry for the short novel and thanks for any help guys,

Clint

 

Might be dumb, are you tuned for this setup?? If you have your stock pump it is prob out of steam, isn't sup the fuel you need.. Under the load is where it will run out. I did a write up on a bosch intank swap

John

 

I just finished reading it actually. Ya, Wheatley tuned for the new motor work with stock injectors and pump. I'm not ready to take the plunge and hack up my $350 semi working fuel pump....I've read several write ups though and I may end up leaning that way with the walbro 255 or the bosch 044. I really dont get why It isnt working though! Is there much tuning to do as far as fuel pressure is concerned after a cam?

 

I ran that same set with a stock pump and stock injectors for 1yr. MY idc was 90 spinning motor allway to 6k. Sounds like you need to get truck tuned for the new cam.

 

You need to find out if your running out of injector, that could be another problem.

you can turn the pressure up on the rail, hopefully someone who has done this will post up

53RUSSELL you beat me, do you think it will help if he turns up the pressure or does he already have enough?

 

Depends on what kinda power your making.. I would think your pump could sup a full bolt on 5.3 but stranger things have happened.. Or you could just buy a walbro255 and run it inline, along with your stock intank. Alot of guys are doing that. Also you might be maxing your injectors out

John

 

i ran my stock injectors with an inline pump in my 5.3 with three different cams till it blew up..have you checked your filter? plugs and wires?

 

Do not increase or mess with the regulator,this will throw the fueling tables out of whack
With that cam even untuned it should not buck and surge
I had that same exact cam,very simple to tune for.
PM me your number so I can help you

 

And there you go

John

 

Well even if my IDC was 90 percent wouldnt it still be getting enough fuel? I read about people trying to adjust the stock FPR with the tamper proof torx thing but I dont want to mask a potentially harmful problem. Theres no way I could be making more than 350 at the flywheel which is why I am confused. Can I check IDC on a scanner like the the modis? (snapon) or do I need to find a tech2? I have access to alot of tools (ie diagnostics and such) I just dont know what I'm looking for. Everyone told me "ahh your stock injectors will be fine and dont worry about the fuel pump. Now that my truck is together and my budget is spent, I'm getting frustrated. Thanks for the fast responses guys.