Idle and drivability problems...

[zeake]

Would the computer listing the engine as a 5.3 when it is a 6.0 cause drivability problems? ? ? ? Would this be the reason my truck runs like pure crap when it warms up. WOT is fine but cruise and it starts missing and stumbling and you have to mash the gas for a second and coast to even drive it. I got an 02 computer relocated IAT and a 2 bar map sensor but. I need to buy credits from hptuners in order to use the 02 pcm. Well I have the old HP tuners and can't seem to add credits to it. My wife goes out of town tomorrow and it looks like I am going to have to rent a car in order to be able to go to work and pick up my kid etc etc etc etc. :wtf: I have been trying to get this thing running right for over a month.
My wife is going to shoot me soon.

I am sitting waiting on a call from Allen. . . .

[RedHeartbeat]

wow, check your fuel pressure regulater. The PCM doesn't care if its a 4.8 or 8.1 if all the settings are correct. A base 4.8 tune when programmed correctly will run any size larger engine.

[zeake]

Fuel pressure is fine and wideband is good as long as your foot is in the gas. The problem is when it warms up and you start cruising . There is no maintaining a steady speed. If you put the cruise on it starts bucking like a dam bull. I love my truck and the turbo is great but what the hell is wrong. I thought sure that would be the issue. Oh well. I still need to talk to Allen about ordering the HPT upgrade. I sure wish I was closer to Nelson Perf cause I'd drop my truck off and tell em to call me when its drivable.

[Chevy366]

Would the computer listing the engine as a 5.3 when it is a 6.0 cause drivability problems? ? ? ? Would this be the reason my truck runs like pure crap when it warms up. WOT is fine but cruise and it starts missing and stumbling and you have to mash the gas for a second and coast to even drive it. I got an 02 computer relocated IAT and a 2 bar map sensor but. I need to buy credits from hptuners in order to use the 02 pcm. Well I have the old HP tuners and can't seem to add credits to it. My wife goes out of town tomorrow and it looks like I am going to have to rent a car in order to be able to go to work and pick up my kid etc etc etc etc. :wtf: I have been trying to get this thing running right for over a month.
My wife is going to shoot me soon.

I am sitting waiting on a call from Allen. . . .

If the engine parameters are for a 5.3L , heck yeah , several thing are different in a 5.3L and 6.0L tune .
If the VIN indicates a 5.3L but the truck has a 6.0L and just the ID indicates the 5.3L then no .

[RedHeartbeat]

Have you tried capping off the vacuum signal to the FPR? I don't think those things were ever designed to work with boost. Once you cap it off, run it for a little while and make sure the FPR isn't leaking fuel out the vacuum hose.

[zeake]

Have you tried capping off the vacuum signal to the FPR? I don't think those things were ever designed to work with boost. Once you cap it off, run it for a little while and make sure the FPR isn't leaking fuel out the vacuum hose.

Yup unplugged it and it runs the same. The AFR goes lean when it runs bad. It goes way beyond the scope of the gauge.
The engine size being different made me think that at idle and cruising it wasn't getting enough fuel.

[RedHeartbeat]

Is it not going into closed loop mode?

[RedHeartbeat]

Sounds like you may have some bad 02 sensors. Could they be lead fouled or something? When you go WOT the PCM does not listen to the 02s, it runs back to the tune only in OPEN loop.

[Chevy366]

Yep , air leak or O2s .
To bad you did not have HPT credits , disable O2s and run SD .
Cylinder volume , air mass , base spark , and several other things , are different between 5.3 and 6.0L

[zeake]

They are fairly new and looked fine when we installed the turbo. Which was a few hundred miles after the engine swap.
I am thinking about borrowing my stepfathers dually that is 2.5 hours away and hauling it to San Antonio. The fuel alone would be over 700 bucks.