backfiring during initial startup
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On The Tree
Joined: Feb 2013
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backfiring during initial startup Hey I was asking around for some advice. Upon firing up my 5.3 swap in my c10 the motor will turn over n back fire. Its open headers and I could see blue flames come out of the collectors. Also I saw flame come up through the intake. I noticed it when I saw through the tb blade. I have a edelbrock pro flo xt intake 90mm tb. I know up n down I installed the cam in correctly but before tearing the front down do you think it's possible for the cam n crank sensors to make the engine backfire. I haven't replaced them. Everything else I did
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From: Ann Arbor, MI
I have accidentally left the cam sensor disconnected and the engine (24x) would backfire and be hard to start. On a swap with a custom harness the cam sensor connector was wired wrong and I had the same symptoms.
We recently has a thread which documented the wiring to an LS1 style cam sensor.
We recently has a thread which documented the wiring to an LS1 style cam sensor.
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Joined: Jun 2012
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From: SV, AZ
Thread Starter
On The Tree
Joined: Feb 2013
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YES. I had it tuned by vengeance racing. I've done a scan and the code I ended up finding is that it's the throttle actuator control module. So I looked it up and it's an electronic tb. My 5.3 was dwb but it has the black cam n crank sensors so I was thinking it was a 24x wheel motor. So I swapped the edelbrock pro flo intake along with cable driven tb. My ecm and harness is setup for dbc. So is there a module of some sort I can use?
I had this same issue the other week on my ls swap upon initial start up and what had happened was one of the cam position sensor wires the pin wasn't slide all the way into the c1/c2 red/blue pcm connectors. I put both connectors because I don't remember exactly where it went off of the top of my head.
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Thread Starter
On The Tree
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The yr motor is a 2003. The ecm is a 411. My harness was done for standalone operations and it's setup for a 24×. Also to note I found out that the code it was giving out was for a tac (throttle actuator control valve) which is for an electronic tb. The ecm is for a dwb not for dbc as I thought
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Verdad Gallardo TECH Regular
Joined: Jun 2012
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From: SV, AZ
Many 411 pcms have the capability to run both.
SERV. NO.- HWD NO. -
12576106 - 12570558 - 2003 G-VAN, LM7, IAC DRIVERS INSTALLED. ALSO C-TRUCK LM7
12586243 - 12583659 - 2004 GTO LS1, IAC DRIVERS INSTALLED
12589462 - 12589161 - 2005 G-VAN, LQ4, IAC DRIVERS INSTALLED
12602801 - 12589161 - 2006 - 2007 Express, Drive by Wire, (has IAC drivers)
These will all work both. Either way this shouldn't be causing backfires.
SERV. NO.- HWD NO. -
12576106 - 12570558 - 2003 G-VAN, LM7, IAC DRIVERS INSTALLED. ALSO C-TRUCK LM7
12586243 - 12583659 - 2004 GTO LS1, IAC DRIVERS INSTALLED
12589462 - 12589161 - 2005 G-VAN, LQ4, IAC DRIVERS INSTALLED
12602801 - 12589161 - 2006 - 2007 Express, Drive by Wire, (has IAC drivers)
These will all work both. Either way this shouldn't be causing backfires.
Thread Starter
On The Tree
Joined: Feb 2013
Posts: 190
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Many 411 pcms have the capability to run both.
SERV. NO.- HWD NO. -
12576106 - 12570558 - 2003 G-VAN, LM7, IAC DRIVERS INSTALLED. ALSO C-TRUCK LM7
12586243 - 12583659 - 2004 GTO LS1, IAC DRIVERS INSTALLED
12589462 - 12589161 - 2005 G-VAN, LQ4, IAC DRIVERS INSTALLED
12602801 - 12589161 - 2006 - 2007 Express, Drive by Wire, (has IAC drivers)
These will all work both. Either way this shouldn't be causing backfires.
SERV. NO.- HWD NO. -
12576106 - 12570558 - 2003 G-VAN, LM7, IAC DRIVERS INSTALLED. ALSO C-TRUCK LM7
12586243 - 12583659 - 2004 GTO LS1, IAC DRIVERS INSTALLED
12589462 - 12589161 - 2005 G-VAN, LQ4, IAC DRIVERS INSTALLED
12602801 - 12589161 - 2006 - 2007 Express, Drive by Wire, (has IAC drivers)
These will all work both. Either way this shouldn't be causing backfires.