vern6.0

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

mrvedit

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.

vern6.0

Ok I have the cam sensor hooked up n crank sensor as well. I'm going to scan it n see what I come up with. I mean the engine turns over with ease

eaglegoat

Did you have a base tune done for vats delete or did you install the bcm too?

vern6.0

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?

eaglegoat

What pcm? What year motor from what vehicle?

Tuckin15s

iTrader: (10)

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.

vern6.0

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

eaglegoat

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.

vern6.0

Now that I recall correctly, the motor would spin n make a pop noise through the exhaust. A backfire would make it spit back up which in my case it doesn't do that. First I'm going to get the ecm changed over if that doesn't solve it I will check the cam timing