Conversions & Swaps LSX Engines in Non-LSX Vehicles
Sponsored by:
Sponsored by:

LS3 won't start

Thread Tools
 
Search this Thread
 
Old Apr 4, 2012 | 04:47 PM
  #1  
JBT's Avatar
JBT
Thread Starter
Staging Lane
 
Joined: Apr 2005
Posts: 56
Likes: 0
From: Stockholm, Sweden
Default LS3 won't start

I have LS3 crate engine with GMPP controller kit that wont start.
I have a fuel pressure thats 54psi...I know it's a little bit low but should it start or not with what fuel pressure?

When I try to start it stumbles for three seconds and then it's like the ignition or fuel is completely cut of. If I don't remove the positive cable from the battery and wait for minute the ECM wont turn on the ignition or fuel again.
If the crank sensor is bad but the cam sensor is working will HP Tuners still show RPM?

I get the following codes from HP Tuners:

[] P0010 - A Camshaft Position Actuator Circuit (Bank 1) (Old) (Current) (Immature)
[] P0036 - HO2S Heater Control Circuit Bank 1 Sensor 2 (Old) (Current) (Immature)
[] P0056 - HO2S Heater Circuit Bank 2 Sensor 2 (Old) (Current) (Immature)
[] P0315 - Crankshaft Position System Variation Not Learned (SES) (Pending) (Old) (History) (Current) (Immature)
[] P0452 - Fuel Tank Pressure Sensor Circuit Low Voltage (Old) (Current) (Immature)
[] P0463 - Fuel Level Sensor Circuit High Voltage (Old) (Current) (Immature)
[] P0807 - Clutch Position Sensor Circuit Low (Old) (Current) (Immature)
[] P2078 - Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High (Old) (Current) (Immature)
[] P0315 - Crankshaft Position System Variation Not Learned


What should I do?
Reply
Old Apr 4, 2012 | 08:56 PM
  #2  
Rick Speed's Avatar
TECH Resident
iTrader: (55)
 
Joined: Oct 2005
Posts: 847
Likes: 0
From: Cleveland, Oh
Default

I believe there is a crank relearn procedure that you do with a scanner. I don't remember if it will keep it from running. But basically you have to start that and then usually you have to run it at 3grand for a few seconds.
Reply
Old Apr 5, 2012 | 05:48 AM
  #3  
rp0029's Avatar
TECH Apprentice
15 Year Member
iTrader: (1)
 
Joined: Aug 2007
Posts: 325
Likes: 1
Default

Did you disable VATS?
Reply
Old Apr 5, 2012 | 05:50 AM
  #4  
rp0029's Avatar
TECH Apprentice
15 Year Member
iTrader: (1)
 
Joined: Aug 2007
Posts: 325
Likes: 1
Default

Didn't see you had controller kit. Nevermind.
Reply
Old Apr 5, 2012 | 07:55 AM
  #5  
psiconversion's Avatar
LS1Tech Sponsor
15 Year Member
iTrader: (5)
 
Joined: Feb 2007
Posts: 1,310
Likes: 11
From: Brick, NJ
Default

Does your switched power source have power when the key is in the 'CRANKING' position?

Jon
PSI
__________________

Your Source for LSX Conversion Parts!
www.psiconversion.com

Ebay Store
Facebook/psiconversion
Instagram/psiconversion

'Dont Let EFI Pass You By!'
Reply
Old Apr 5, 2012 | 09:42 AM
  #6  
Jesus Freak's Avatar
Launching!
10 Year Member
 
Joined: Feb 2011
Posts: 203
Likes: 0
From: Salem, OR
Default

Are all your grounds well connected? As well as the body of the ECU grounded?
Reply
Old Apr 5, 2012 | 10:59 AM
  #7  
JBT's Avatar
JBT
Thread Starter
Staging Lane
 
Joined: Apr 2005
Posts: 56
Likes: 0
From: Stockholm, Sweden
Default

ECU body is not grounded, i'll try that on sunday.
All other grounds are connected to the block and heads.

The switched power source is connected directly to the battery.


All ideas and thougts are welcomed!




Thanks

Jacob
Reply
Old Apr 5, 2012 | 11:29 AM
  #8  
lizeec's Avatar
TECH Resident
iTrader: (57)
 
Joined: Sep 2009
Posts: 753
Likes: 20
Default

Your switched PCM wire needs to be connected to a switched power source that has power when in the cranking position, it can't be connected to the battery and powered at all times.
Reply
Old Apr 5, 2012 | 11:34 AM
  #9  
cutlass_455's Avatar
TECH Enthusiast
iTrader: (2)
 
Joined: Aug 2008
Posts: 617
Likes: 0
From: Alberta, Canada
Default

Also, your engine needs to be grounded to the frame. These engines need to be grounded lots, the ECMs like it.

I got ground strap from the back of the block to the body, front of the head to the frame or the battery negative, I cant remember right now and its a BLIZZARD outside today and I cant find my cars.
Reply
Old May 8, 2016 | 03:06 PM
  #10  
LS36.2 problems's Avatar
Registered User
 
Joined: May 2016
Posts: 1
Likes: 0
Default ls3 wont run

I have almost the same error codes and won't run, did you get it to run and what was the problem? Thanks
Reply
Old May 8, 2016 | 04:47 PM
  #11  
Kamaro's Avatar
On The Tree
 
Joined: Feb 2013
Posts: 184
Likes: 2
Default

It may sound silly, but are you sure you got the MAF in the air intake tube and connected to the ECU harness correctly?, if I get the MAF disconnected or not inserted in its slot the engine would run for a second or two and then will die.
Reply




All times are GMT -5. The time now is 11:08 PM.