LB7 no power, no codes

[05LLYDMAX]

I have a 305k mile 2004 LB7 in the shop that recently had heads done. I was brought the truck afterwards with a lack of power issue. MAF, MAP, BARO, balance rates, rail pressure, boost, wastegate, and MM3 are all working properly. Truck had a Hypertech installed and would not take a stock flash, swapped ecm with good stock flash and no change. We did notice that main injection timing falls from 3.0 degrees at 40% throttle to 1.0 degree at 100% throttle. Customer states power issue wasnt there before heads, but also has a different story each time I ask a question. lol. I did find a receipt for injectors done september of 2015 which was 120k miles ago. Any info is much appreciated.

 

[05LLYDMAX]

Truck drives like it has a MAF issue, takes off a little sluggish, shifts rough and slowly ramps in power.

 

[Dukchunter]

Is truck building boost? With the heads being off there are so many possibilities of what could have happened. Any codes?

Sent from my SM-G960U using Tapatalk

 

[05LLYDMAX]

Is truck building boost? With the heads being off there are so many possibilities of what could have happened. Any codes?

Sent from my SM-G960U using Tapatalk

no codes, builds 18-20psi. bone stock truck.

 

[2004LB7]

What temp does your ecm think it is?

Also, you say "MAF, MAP, BARO, balance rates, rail pressure, boost, wastegate, and MM3 are all working properly" can you post numbers please.

 

[05LLYDMAX]

What temp does your ecm think it is?

Also, you say "MAF, MAP, BARO, balance rates, rail pressure, boost, wastegate, and MM3 are all working properly" can you post numbers please.

AT idle 154 degree coolant
MAF: 5.2lbs
MAP: 14.0LBS
BARO: 13.9 LBS
MM3: 8.8
FRP: 5253 ACTUAL. 5221 DESIRED
TIMING: -3.0

 

[2004LB7]

Is it a federal or California version?

 

[gmduramax]

AT idle 154 degree coolant
MAF: 5.2lbs
MAP: 14.0LBS
BARO: 13.9 LBS
MM3: 8.8
FRP: 5253 ACTUAL. 5221 DESIRED
TIMING: -3.0

Coolant needs to be 160* before it’ll give full fueling IIRC

 

[05LLYDMAX]

is it a federal or california version?

federal

 

[05LLYDMAX]

Coolant needs to be 160* before it’ll give full fueling IIRC

Yeah it does the same thing at 190 as well

 

[Chevy1925]

Put up a good decent log of it, nate.

just fyi guys, he has pondered this over with Steve (the old Tuna Man himself) and i on this issue. i have not gone to see the truck yet but this is a really interesting one.

 

[05LLYDMAX]

Put up a good decent log of it, nate.

just fyi guys, he has pondered this over with Steve (the old Tuna Man himself) and i on this issue. i have not gone to see the truck yet but this is a really interesting one.

oh boy, no clue how to do that :roflmao:

I only know how to email for tunes sake bahaha

 

[gmduramax]

Put up a good decent log of it, nate.

just fyi guys, he has pondered this over with Steve (the old Tuna Man himself) and i on this issue. i have not gone to see the truck yet but this is a really interesting one.

Oh wow the black cloud is over everyone :spit: anything I touch has been the same.

 

[Chevy1925]

oh boy, no clue how to do that :roflmao:

I only know how to email for tunes sake bahaha

take log file, right click, saves as .zip file, open DD, click "go advanced" in this thread like you are making a reply, scroll down to "manage attachments", click on it, choose the .zip file, click upload and then click "submit reply". Finally, bring me a beer bitch :roflmao:

Oh wow the black cloud is over everyone :spit: anything I touch has been the same.

This one is one of those that "just needs to go" lol

 

[05LLYDMAX]

INJECTORS! Had a set here I decided as a last resort to toss in and she runs good as new. thanks guys :woott:

 

[2004LB7]

So what was in there before? 45 unders?

 

[Chevy1925]

So what was in there before? 45 unders?

old worn out POS injectors. which is strange that main injection rate was 8mm3 and balance rates were all no more than +- 1. i think they had more of a solenoid issue.