my injector flow rate is maxing out early

[5.3]

ok so i just swaped a 6.0 motor in my 05 4.8 truck. i uploaded a stock 6.0L tune to PCM then i go out to log couple WOT runs and wow im at 118% INJDC 1 and 2 @ 4000RPM ??

why is my injectors maxing out so early is it tuning or is it something electrical

thanks

[mistermike]

Are the injectors the correct ones for the 6.0 tune? It may be that your fuel pressure is different than what the 6.0 tune is expecting, or possibly insufficient pump for that big motor. A wideband would certainly allow you to see what's going on quickly.

[kbracing96]

Is the motor built? From the factory, the 4.8,5.3,and the 6.0 all use the same 25ish lbs/hr injector, so if it's only a mild N/A 6.0, you shouldn't be running out of injector. Also, is your truck a return, or return-less fuel system? Does it have a vacuum referenced fuel pressure regulator? Your 6.0 tune might be setup for return fuel system and your truck may be a return-less. Is your IFR table flat or sloped? These are some thing to check.

[5.3]

its a stock LQ4 out of out of a 04 HD truck i used the included intake manifold and injectors ...i have the returnless fuel feed all i did was add the LPE GT2-3 cam/springs and some long tube headers and a trailblazer stall converter..

this is crazy IFR setting is from an o4 Silverado SS.. i just came back after trying two other 6.0L tunes and my injectors still maxing out at 4000-5000RPM..truck also feels slower in the upper rpm...

[5.3]

oh yeh i wanted to add that out the showroom floor on my totaly stock 4.8 i used to see around 80% INJDC @5500RPM

so is it normal to runout of injector on these returnless fuel systems ?

thanks guys

[wait4me]

All that it is saying is that your engine needs more fuel than the injector can supply.

If your a/f is correct and it is that high then you just need to go up in size to get you back in line with the recomended 80 to 90% buffer.

Minipulating pressure will adjust the difference. Due to the injector being able to flow more fuel at higher pressure.

[5.3]

wait4me funny you replyed to this thead cos i emaild you twice in the last week about getting a profecional email tune for my radix and 6.0L swap im still wait4you to reply back :D .. i didnt install the Radix yet im waiting to get the tune first..

thanks man

[wait4me]

lol. Sorry, im still getting about 200 or so emails a day. I have 2 people going thru them and trying to answer them all, but it is very slow. The best thing is to just call, :) Thanks Jes

[5.3]

ok man thanks