Dansic

Not sure where else to ask this.

I have a 96 CCLB K3500 I got as a shell. I picked up an LQ9 from LKQ for like $650 and rebuilt a 4l80e for it. Its been running in the truck for a while now, but I gotta say its been underwhelming. Its not a dully or anything, and I had an LQ4 in a ECLB K2500 that felt WAY more peppy than this. The extra 10 inches of truck didnt really make a difference in unloaded weight between the two trucks. It just feels sooooo damn slow. It just wont accelerate any harder after a certain amount of throttle. (like maybe 1/3) I can't tell if the engine is just too underpowered, or if maybe something is wrong in the trans or engine management. Nothing shakes or shudders or makes weird noises... Would you think a stock LQ9 would feel super slow in a crew cab? Based off my K2500 I wouldn't think so. Its being run by a Fitech controller, the same controller from the K2500, just reset and relearned. Engine oil is clean, trans fluid clean, new carrier bearing and diff oil. Idk what to think about it.

AgFormula02

iTrader: (13)

what tranny in both rigs? What rear end in both?

Dansic

k2500 had a 700r4 and the K3500 has a 4l80e. Both had 4.10 rears

theunderlord

Get it chassis dyno'd?

Che70velle

iTrader: (6)

Did you have this professionally tuned? There’s a ton to be gained with a good tune in any vehicle.

QwkTrip

iTrader: (23)

I have a friend with a Gen III 6.0L 3/4 ton truck and it's a dog. As he told me once, "I wouldn't care if it was so slow if it just got better mileage, but both suck." Engine seriously needs some tuning.... baaaaaaaaad. Guessing that might be what's ailing you too?

Dansic

So the truck is running a Fitech system. Its self tuning. The engine is completely stock intake to oil pan as well. I'm not sure how much I can really effect the tune using the handheld, its all pretty basic stuff really. Its hitting the AFR tagerts and it doesn't SEEM to be taking a bunch of timing out. I'm trying to log some data with it. The engine overall seems to be running perfectly fine. Clean plugs and oil. It just seems way slower than it should be.

theunderlord

The Holley Terminator ECU's claim that as well, but it doesn't really work that way. Having a professional go over things is always a good idea.

AgFormula02

iTrader: (13)

there is a huge difference in gearing here m, specially first.
the steep 1st on the 700r4 would make it a lot more peppy off the line

Firebirdmuscle

iTrader: (16)

if the compensation is adding or removing a lot of fuel to get to target it probably wouldn’t hurt to dial things in closer.

also if just using a simple timing map maybe it doesn’t have enough timing in it to begin with and that’s why it feels doggy.