LS Swap P0171 Code Bank 1 too lean HELP

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jfkelley

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LM7 / 4L60e / NP241C / LSXceleration Stage 2.1 Cam 218/227 .523/.523 HR112+3, Delphi GM LS7 Lifters & Lifter Guides , LS6/LS3 Valve Spring, Brand new O2 sensors, just drive it home from
Tuners..
I keep getting bank 1 too lean and then it runs like crap like it goes into limp mode
No Throttle response acts like it’s missing ..I have to disconnect negative battery post to reset computer ..I have checked for vacuum leak @ intake , Booster hose , exhaust manifold , PVC hoses , checked all injector connections I’m running out of ideas ..Your input would be very helpful ..Thanks in Advance
 

Blackbeard44

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P0107 is a MAP sensor code

have you tried to swap it out with a know to be good one.

any rhyme or reason it acts up? will it idle just fime for a long time? does it only act up after a WOT pull? can you drive it nicely and it wont act up? is your gas good and fresh?
 

Blackbeard44

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good fuel pressure?
fresh fuel?
MAF clean, and honeycomb intack? how far away from throttle body is it?
it seems that code is tripped from upstream o2 detecting to much air.
 

jfkelley

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@Blackbeard44 50+ fuel psi - Cleaned the MAF / Honeycomb intact / MAF is on Cold air intake right after the filter coming from passenger side ..I will check header bolts tomorrow
 

Blackbeard44

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i cant speak from experience, I read a couple write ups and it seems MAF sensor is a common cause, in your other post you metioned using a tuner, did you have someone tune it?

Im only asking because when I had my truck tuned the tuner mentioned rookie half ass tuners like to manipulate MAF readings to increase power and its not good and rarely works.

just what I heard, and im not too computer savy myself to figure out tuning
 

jfkelley

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I did have someone Drive tune it …I’m trying to figure out how to take down that other list ..Didn’t mean to double post it ..The tuner said if I can’t figure it out he will drive out to my house next week and try and figure it out
 

Blackbeard44

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leave that other post up, that person seems more knowledgable than me, Ill start using the other post as well
 

Vbb199

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You dont have a way to data log and access the file from the pcm do you?

I could help you remotely.
 

jfkelley

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@Vbb199 Checked fuel pressure @ 50psi , No Diagnostic codes , checked all ground , checked connections on Injectors , Coils spark plugs , coil wires ..Just re-checked the situation. While there is plenty of fuel, I think that the spark is either intermitt or missing on the driver's bank. The drivers side exhaust is cold / warm and the passengers side is too hot to touch

After researching of a few forums
1. Broken valve spring
2. Bad ground on back of head (might try ohm it to make sure that wires not broken internally)
3. Bad ECU

anyone have any other ideas ?
 

Vbb199

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@Vbb199 Checked fuel pressure @ 50psi , No Diagnostic codes , checked all ground , checked connections on Injectors , Coils spark plugs , coil wires ..Just re-checked the situation. While there is plenty of fuel, I think that the spark is either intermitt or missing on the driver's bank. The drivers side exhaust is cold / warm and the passengers side is too hot to touch

After researching of a few forums
1. Broken valve spring
2. Bad ground on back of head (might try ohm it to make sure that wires not broken internally)
3. Bad ECU

anyone have any other ideas ?


Temp check your primaries with a infared gun...

Normal temp at idle will be around 450ish degrees at each one.

Might be able to isolate a cylinder.

Hotter is richer, colder primaries can be misfiring, or mega lean


Edit: Spark plug condition will solidify that
 

jfkelley

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jfkelley

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Vbb199

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29° if advance @ 790rpm seems pretty high for a motor thats 156°

What is MAP kPa?
 

jfkelley

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Let me see if I can’t get that info
 

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