no power at any throttle cammed 4.8

[That_Red_8.1]

I need help i recently cam my truck with a chopacabra cam. The bottom end is bone stock and in pristine shape leak down test 5% and down on all 8, 180psi of compression on all 8, no co2 in coolant the head gasket good the cylinder still have its crosshatching even tho it has 190000mile.Here the list of part ive put:

-chopacabra cam 214\222 .550 108 lsa 106 icl
-ls6 yellow spring
-che trunnion upgrade
-dod stock high volume 5.3 oil pump
-TBSS intake
-36lb injector
-255lph fuel pump
-throttle body 90m edelbrock
-e fans
-3in double full straight
-8mm spark plug wire
-8x tr55gp
-8x coil
-cam\crank sensor gm
-stock 4l80e conversion with stock torque converter tho

My truck is a 2wd ext cab short step side bed it weight 4950lb 3,73 and that cam is supposed to put down more power and torque even in low rpm range. Its my daily im really done putting money in fact there s more to come but i want to at least run great before i got 243 head milled .030, gm88ss 2400 stall torque, stage 2 4l80e i dont have a controller for my wideband. And to be honest the budget is too tight now im 17. Before that truck was fun to drive now its a dog slow now when i floor it from a stop it doesnt even chirp the tire i know the stock stall isnt the best now but still. the harness is 100% good all ground is 6x checked. No code. ive tried 4 map sensor. i really need help cause right now im clueless i got 65psi fuel pressure on load not just free revving in neutral. in park neutral it rev like a carburetor and crazy choppy idle but now its all sound no go. Even if im already driving it dowshift and nothing crazy it was better stock my lq4 stock cam 80lb injector savana 6500lb move way more. the rpm as the cruise effect. And i have a exhaust manifold leak on bank 1 that why theres a difference between bank 1 and 2. but the spark plug look all the same. But i think its more a problem than tune related cause i have a log (the injector data wasnt even right) and still it burn in second gear which i tought it was good but since that log i feel like im in a 4cyl minivan.good run.hpllast run.hpl4.8 cammed 4l80e stft ltft enable.hpt

[horsepowerguru427]

Referenced or non referenced fuel system? What's the injector part number, there are lots of 36lb injectors and the data isn't the same across the board.

[That_Red_8.1]

gen 4 12613411 i dont know why it wasnt in the good run log but i have the right value cause ive been running those injector with the tbss intake since 1 year

[gametech]

You should manage expectations. Even when you get your tune sorted out, a 4.8 with that cam and a stock stall with a 4l80 will be an absolute dog for daily driving. All those engine dyno numbers you see showing the torque gains don't start their pulls until well over 2000rpm, and usually closer to 3000rpm. The 4l80 has a higher first gear ratio than the 4l60, so you lose a good bit of off the line torque multiplication. A 3600 stall converter might make things a lot more acceptable.

[Alvin]

This looks lean at wot. Timing is a bit excessive.

and that cam is supposed to put down more power and torque even in low rpm range.

The people marketing these things lie. Expect gains at absolute full throttle. i'd guess above 4000RPM and expect a loss with that cam in that setup everywhere else.

[RDF1]

Perfect example of a combination that parts dont compliment each other.
My neighbor did the chopocobra in a 4.8 with stock converter 4L60, 3.42s, and 35" mud tires.
It was absolutely terrible. He wasnt happy with the whole setup. He believed the marketing as well.

We put 4.56s, Trutrac Diff, 275/55/17's, 3800 converter, 1-7/8" headers on the truck and i retuned it for him. He went from not being able to spin a tire on wet road to needing 4wd to get it to leave on a dry road.
The little 4.8 needs rpms to make some power. So the 2400 converter you mentioned wont be worth the money you spend on it.

Depending on your tire size you might want to go to a lower gear and a much better torque converter. If its a play truck i wouldnt go less than 3600 converter if you want it to perform. If its used for towing then you have to think about where you want to compromise.
That whole combo just isnt going to be spectacular in the performance aspect.


Add a turbo and then you can make enough torque to make the 4l80 useful.

[That_Red_8.1]

i totally understand the gearing setup isnt optimal but still. i know a friend with the config minus the intake and he just leave me in smoke. Plus its a daily i dont want to put such a high stall converter. And i totally understand that a 4.8 need to rev but even at high rpm its really slow like it feel like i lost 150hp at 4500rpm or any rpm. i think its a problem electric or whatever rather than a tune or setup related. i tried other injector 50lb and it still want more more more fuel im getting no knock. i just reverified the cam alignement it was good i don't think the cam is not grinded correctly. plus when i floor it from a dig it pop with in the intake so i understand less power at low rpm but it’s worse than what you think. i checked all ground no resistance and added some the pcm is getting voltage no result. No code

[2xLS1]

The people marketing these things lie.

But I bet it has a mean sounding idle. I mean chopacabra.

[bk2life]

Plus its a daily i dont want to put such a high stall converter.

if you tune it to lock up above 35 mph, it will drive like a stock convertor

[That_Red_8.1]

even when its unlock in 1st from a roll past 4000rpm or from dig its awfull

[RDF1]

i totally understand the gearing setup isnt optimal but still. i know a friend with the config minus the intake and he just leave me in smoke. Plus its a daily i dont want to put such a high stall converter. And i totally understand that a 4.8 need to rev but even at high rpm its really slow like it feel like i lost 150hp at 4500rpm or any rpm. i think its a problem electric or whatever rather than a tune or setup related. i tried other injector 50lb and it still want more more more fuel im getting no knock. i just reverified the cam alignement it was good i don't think the cam is not grinded correctly. plus when i floor it from a dig it pop with in the intake so i understand less power at low rpm but it’s worse than what you think. i checked all ground no resistance and added some the pcm is getting voltage no result. No code

A quality converter such as CircleD converter drives very nice for such a high stall speed. It only flashes high when you give it enough throttle.
It still wants more fuel with 50# injectors as in your wideband is telling you its lean at WOT?

And the intake pop from off idle sounds like tune is way off or you have a fuel pressure issue.

[Alvin]

A heavy truck with a loose stall sorta sucks to drive around. I'd find someone else's truck setup like that.. drive it and see if that is something you want.

[RDF1]

What size are your tires?

[That_Red_8.1]

29in tire they're small. i dont have controller for my wideband so i use the narrow band. The fuel pressure never drop under load 65psi steady and i even try to increase drastically by 20% the VE table to see if it was lacking fuel and my narrow band were off but be free to check the tune. Open loop of closed loop no change

[gtstorey]

Was the injector data set up for 65psi? Not that it would make it run lean, but the standard injector would not be correct for 65psi.

[That_Red_8.1]

411 injector are 38lb at 58psi at 65psi it = 40lb its not that off

[gtstorey]

What about the rest of the injector data? And what are you using to regulate it to 65psi?

[That_Red_8.1]

stock 2013 returnless silverado l96 pump with walbro 255

[That_Red_8.1]

What keep me thinking its a problem like i dont know pcm, electric... rather than tune related is I made a few pull with a 60e unfortunately i dont have log and it was way less fine tune but she was moving especially for a 4.8. i know the 1st gear (3,06) is better in a 60e for a 4.8 i was ready to conceive less accel for way more durability with a 80e with 1st gear (2,48). But now it just pop in the intake and slow as much at high rpm as at low rpm.

[RDF1]

You need torque to make a higher gear perform. The 4.8 doesn't make much toque and especially with that cam it moved the power up in the rpms so it takes a long time for it to get into peak power.

For instance the last stock 4.8 i had on the dyno only made about 92rwhp/170tq at 2000 rpms.
Imagine adding a cam and losing some of what little torque/power you had down low.