djloc79

Ok folks,
been trying to start this engine for the last few days. L92 into a 96 V6 camaro. 24x computer and wire harness from schwanke, Lingenfelter converter box...
problem I've been having is that it backfires but won't start. Now i'm new at this but my guess is there's a problem somewhere with the lingenfelter box and the engine/ecm communicating. had a mechanic friend over today with a scanner. computer showed no error codes. he's not familiar with the lingenfelter box but advised me to get him more info. Any ideas? before i had the backfiring, the converter box would light up red when i turn on the key but would go out when i turned the starter over. later figured out that i needed to use a different power source. one that didn't switch off and on while cranking. after that, the converter box would lite up red when i turned the key, and green after about a second of the starter turning over. and thats when the backfiring started.
i'm stumped!!

BanditDave

iTrader: (11)

While this may not be the actual final issue, what cam sensor are you using and have you confirmed it is the correct one for the harness you are plugging in? Reason I ask is because if you bought it from a generic parts store - Pep Boys, Advance, etc... they do not realize that there are differences and oddly enough around my neck of the woods they stock the GTO style cam sensor with the wires + and sensing lines swapped. This will give you problems starting and my guess is because the box is relying on this it may be more important to running than say your typical LS Carb swap with the MSD box. MSD looks at the cam but the car will still run without it.

Another scenario, although somewhat more grim, is the installation of the cam. Was this motor a used or sealed motor you dropped in or is it fresh off a rebuild?

Just throwing some scenarios out there for you. More info on your set-up is definitely needed.

djloc79

The engine came from
RetroLSX out of Georgia. It has 12000 miles on it. Before they sent it to me, they change out the escalade intake and cam for the ls3 intake and cam. Could something have gone wrong there?

BanditDave

iTrader: (11)

Refresh my memory...does the L92 have VVT? If so did they use the correct cam gear, etc...for the Lingenfelter box? If it was VVT then there is a decent amount of stuff that has to change in the front of the engine for it to work. Let me take a look at the instructions when I get home.

Dave

rojs234

iTrader: (5)

Not sure if this will apply to your situation, but it might be worth a try. If you are using a harness that was made for the rear mounted cam sensor (like LS1 or 5.3 vortec) and your new engine has a front mounted cam sensor, you probably need to switch positions with the A and C wires on the plug that plugs into the cam sensor. These are the two outside wires on the plug and usually they are marked. My LS2 with a 24x and a 6010 box would not start and backfired until I switched these wires. After...it started instantly. Had the same problem with a Gen lV 5.3 using a 2002 harness and 411computer. Just something to consider....Ron

deuce4935

iTrader: (2)

Did you ever unplug the coil harness? Make sure its properly connected, I know it looks fool proof but I had mine on backwards and was getting backfiring along with no start.

Jason Haines @ LPE

If they changed from an L92 camshaft (has camshaft phaser) to an LS3 camshaft (no camshaft phaser) then they would have had to have changed the timing gear and the front timing cover. The LS3 production timing gear would have the correct reluctor wheel tooth count.

You do have to change to the LS2/LS3 front cover because the cover depth is different between the L92 and LS3 front timing cover. I am assuming that was also changed.

The front mounted camshaft sensor is the same for the 24x and the 58x engines (LS2, LS3, LS7, L92 etc). They have had several number changes and color changes over the years on the front cover mounted camshaft sensor but all of the different sensors that will bolt to the LS2/LS3 cover will work with either reluctor and will work with our trigger conversion module.

Our module should be plugged directly into the camshaft sensor. Do not connect to the jumper harness on the timing cover and do not use an adapter harness in between.

Unless you are using an E40 ECM (2005 Corvette, 2005-2006 SSR, 2005-2006 GTO), our module should also be plugged directly into the camshaft sensor connector on the engine harness.

We have had some customers connect one of the conversion module connectors to the MAP sensor harness. The connectors are keyed differently but you could force it if you really tried. Normally it sets a diagnotic code if you do this though.

If the camshaft sensor is connected properly I would check to make sure the injectors and coils are wired up correctly (for the correct cylinder #s/firing order).

djloc79

U mean u had the odd coil connector on the even side, and vice versa?
My harness has it labeled but I guess it could be wrong. What would it hurt to check and see if they're wrong? Theoretically the engine should start. On the other hand if they're already correct and I swap them, then what? Could I damage something?

BanditDave

iTrader: (11)

I doubt you will damage anything but it would be like you had a distributor in 180 out...it wwill backfire like a **** but never start.

Shot in dark here...what starter are you using, as well as what battery?

djloc79

I purchased a new battery for a 96 camaro. 1000 cranking amps. 800 cold cranking amps. It's been a while since I bought the starter. It's a reman starter from a Tahoe I think. I need to check and make sure.

djloc79

Ok I Checked, it's an 08 escalade starter. Very curious to know why u asked.

djloc79

Something I just thought about, while joining the motor and trans together, I used a long handle ratchet to turn the harmonic balancer in order to put the flywheel/converter bolts in. Is it possible that I rotated the wrong way? And could this be causing the problem I'm having now? I do remember hearing a pop as if something in a bind released.

djloc79

This just in.... The motor ran for about 4 seconds. Only changes I made was I put the egr covers on the headers and I unplugged the the cam sensor. It tried to run maybe once or twice afterwards but no more backfiring. So whadya think?