Diablosport Forums

I have an 05 Silverado 5.3 Z71 running a U7193 and i am having issues with lack of acceleration from a dead stop. Once the truck gets up to 3k it pulls really hard and goes. I understand that i cannot use my 7193 for logging AFR, but i have access to a Snap-On Solus Ultra scanner/diagnostic tool. It has graphing capabilities and lists a AFR pid. Would i be able to use this for reference to adjust my PE? If so what is the ideal AFR for my truck? I have a Spectre CAI, ported and polished TB, Trans Dapt torque swirl spacer and have removed the muffler from the stock exhaust. I have adjusted my LTFT's using LogRedux and appear to be in range.

PE is for WOT fueling... and what you're describing, sounds like at WOT it's pulling fine...

you need to work on low-end part-throttle stuff....

do a steady driving data log to see where your average long term fuel trims are at, and make a part-throttle fueling adjustment by adjusting the injector slope...

also, even more can be done for your truck/predator with a custom tune for it....

[quote="06MonteSS"]PE is for WOT fueling... and what youDid another cruise log and ran it through the redux. It told me to drop another 3 percent. I already had it adjusted -5 percent. I had reached that setting after multiple logs and reductions and it had leveled out. Why would it change now? Ambient air temp maybe? Air conditioner? The last time i did the adjustments and logs it was around 85-90 degrees. Today it was 75. Also my acceleration issue from a stop is at WOT. Stop sign, stomp gas, dent floor pan=seriously unimpressive takeoff. It reminds me of my moped when i was 14. I understand that the custom tune is going to improve things, but will it solve my total lack of tire smoke? Otherwise am very happy with the economy i am getting out of the high octane tune, breaking 20 easily on highway with solid 17's around town. Seems to be decent for a full size 4x4.

06MonteSS wrote:PE is for WOT fueling... and what you're describing, sounds like at WOT it's pulling fine...

you need to work on low-end part-throttle stuff....

do a steady driving data log to see where your average long term fuel trims are at, and make a part-throttle fueling adjustment by adjusting the injector slope...

also, even more can be done for your truck/predator with a custom tune for it....

Are what you are trying to say is that my acceleration lag is from the time the computer takes to compensate for not being close on long term fuel trims?

getting your fueling adjusted helps with throttle/acceleration response... is that your only cause of lag?? no.. but it does help, and is the only thing you can somewhat do yourself via the tool...

if you want real/even more improvement, get a custom tune done for it by a diablosport CMR custom tuner, like myself

06MonteSS wrote:getting your fueling adjusted helps with throttle/acceleration response... is that your only cause of lag?? no.. but it does help, and is the only thing you can somewhat do yourself via the tool...

if you want real/even more improvement, get a custom tune done for it by a diablosport CMR custom tuner, like myself

So the moral of the story is that it doesn't matter if i can read AFR pids with a different tool, because of the limitations of the predator? After all the time invested in tweaking and monitoring, the gains will be insignificant? Leaving the end result spending more money with you for a custom tune? If PE is based on AFR, and my 7193 wont log AFR, what do you base PE on for your custom tunes? I am not asking these questions merely to be a pain in the a$$ but I would like to understand the process, and I like to be sold on a product, a good sales pitch helps me to be confident in my purchases. Because I am interested in a custom tune, if it will give me the results i want, but i'm kind of a tight wad with my cash, and i like to know why I am spending it.

Or is the real moral of the story I am being unrealistic about the performance potential of a basically stock fuel injected LM7 in a full size 4x4? Do my limitations lie within the basic design of the engine components themselves? Should i just face the reality that I am not going to improve anymore "on the cheap" and live with the fact that i'm not going to gain anything without a cam swap or cylinder heads or even an LQ9 swap. But then i still need a custom tune to make those components work. So it leads me back to believe that the key component is the tune.....

Just to let you know my truck was doing the same thing and it ended up being #8 coil was bad.Check exhaust manifold temp at each cylinder exhaust port and if one is running cooler then the rest that may be your problem.

gagliano7 wrote:Just to let you know my truck was doing the same thing and it ended up being #8 coil was bad.Check exhaust manifold temp at each cylinder exhaust port and if one is running cooler then the rest that may be your problem.

What symptoms were you having? I have no misfires and no codes. Other than doggy from a standstill my truck runs well.

You do need to remember it is a truck...and heavy. Sure you can make it a little better but thats about it. Its not going to be a tire smoking demon if thats what you want. I have a 01 that now has a cam and heads on it. I tuned it myself and have the TQ managment set up to where its safe on the tranny but still has alot of power. No tire smoke from a dead start. Sure if i wanted to kill the TQ mngmt it would do it. But its not realistic with my mods.... And would kill the tranny.

smokestack wrote:You do need to remember it is a truck...and heavy. Sure you can make it a little better but thats about it. Its not going to be a tire smoking demon if thats what you want. I have a 01 that now has a cam and heads on it. I tuned it myself and have the TQ managment set up to where its safe on the tranny but still has alot of power. No tire smoke from a dead start. Sure if i wanted to kill the TQ mngmt it would do it. But its not realistic with my mods.... And would kill the tranny.

Thanks for the input. I should just be happy with the economy i'm getting and the moderate power gains.