3pedals

iTrader: (3)

I run a 6012MSD box. every 2nd time I crank the starter the engine will not start, and it will backfire. MSD throws a "cam sensor fail" code. I changed cam sensor, and went through a bunch of tests while on the phone with an MSD tech, but no -luck, testing indicated a faulty MSD box, MSD replaced the box, but the problem persists with the new replacement????
Anyone else have similar problem, and find a solution??? I am sarting to think the MSD wire harness is bad, or I got a bad cam sensor when I replaced it?

quickinda6

I would look into faulty connections, dirty loose etc
Vinny

ZONES89RS

iTrader: (25)

Yea, sounds like a faulty connection somewhere to the ignition controller.

3pedals

iTrader: (3)

thanks guys, I'll go over all the connections again.

burgers

iTrader: (77)

I had a bad reluctor wheel on a scat crank that did the same thing. It spun just enough to cause all kinds of issues. Also what front cam gear are you running? Check your ground on the back of the motor and make sure the ground wire on the msd harness is ground to the block or chassis not aluminum such as manifold or valve covers.

stripes1987

iTrader: (6)

do you have a normal cam pickup in the back or is it like an ls2 where the cam pickup is on the front cover? it does make a difference. i believe i had heard something about if it is the cam pickup on the front cover you have to do something to reduce the voltage or increase it or something like that. if you have a front cover cam pickup let me know and i will find out what you are suppose to do. i have a buddy that had the same problem with it starting. there is another deal that i had a different friend deal with where, you have to have i think it was 11.5 volts to the box or it wont start. it has some cut off switch in the box or something where if it sees below 11.5 volts it will not turn on at all

pm me if you have any questions.

thanks,
David

3pedals

iTrader: (3)

David, I have a relay switched wire dirct from battery to MSD box to ensure proper voltage durring cranking. The MSD is grounded to the aluminum valley cover(is this the problem?) I have the LS2 front cover and cam sensor, with a 4X cam gear.
I appreciate you finding out for me.
Barrett

stripes1987

iTrader: (6)

I would deffinatly change the ground and put it on something like the block its self or even on the back of the cylinder head where the original ground is on the ls motor. i am waiting on a call back from a buddy of mine that was the original one that gave me the info on the ls2 timing cover setup with the msd box in the first place.

3pedals

iTrader: (3)

thanks, anxious to hear what your buddy has to say.

stripes1987

iTrader: (6)

he said that the ls1 cam position sensor takes 12volts and the ls2 sensor takes 5volts. he said that you have to switch a few wires around but he wasnt possitive off the top of his head. he said to call msd and ask them about this and they should be able to tell you which wires it is.

68 RS Convertible

iTrader: (1)

I have a 6.0 iron block, 58x reluctor wheel with MSD 6012 box. Cam sensor in the front cover and 4x timing gear. I didn't have to switch any wires. I did read a few threads about having too switch two of the wires going to the front cover but I thought it had something to do with msd box reading low motor cranking speed. I could be wrong about that though.

rojs234

iTrader: (5)

I don't think I can solve *3pedals* problem but I can add a couple of facts to the discussion that might help someone else. If you have a Gen lV engine that has a 24X reluctor ( there are a lot of these) you will use the MSD 6010 box. The harness that comes with this box has the connector for the rear mounted cam sensor. You need to extend the wires to reach the front mounted cam sensor on the Gen lV and you MUST also switch the A and C wires on the connector that plugs into the sensor mounted ON the front cover. I failed to do this on mine and when I tried to start it, all it would do is backfire. After switching the wires, it started instantly. We also ran into this on a 5.3 Gen lV we recently installed in an old Ford pickup. It was also 24X so we used a harness and computer off a 2002 5.3. We had to extend and switch the wires on this setup also. This engine had an extension from the sensor down to pan level with a different connector that the early cam sensor connector would not plug into. We discarded this piece and plugged the early connector into the plug where the sensor is midway up on the front cover. Plugs right in. If you download the instructions for both the 6010 and 6012 from MSD, and look at them, you will see that BOTH have 3 wires to the cam sensor plug.....a ground, a sensor wire and a pink 12V wire for pin-C on the 6010 and a orange 5V wire for pin-A on the 6012 The ONLY difference I can find is the two outside wires, A and C are switched. Hope this helps, Ron

3pedals

iTrader: (3)

I have still not solved my issue. I am starting to think the replacement cam sensor I have is faulty as well. that is my next pursuit.

ZONES89RS

iTrader: (25)

Damn, hope you get it squared away, i know if i was you i would try my box on a friends car and see if it was anything different, but i have friends with the same setup as me, you have anyone that could do that for you?

3pedals

iTrader: (3)

I already have a replacement MSD box under warrantee, so I cant beleive that it could be bad. Car runs awesome, just have to crank it 2-3 times occasionally to get it to fire??? I dont know anyone else personally that has done a carb ls conversion around here using a 6012 box

ZONES89RS

iTrader: (25)

No one i know, we are all running the 6010 around here.

67firebirdak

I'm also using the msd 6010 box on my 5.3, and the only problems I have is hard starting when the engines hot (this is just carb problems). I have mine grounded to the passenger side head and have had no problems with ignition problems like yours. I did notice when I advanced the idle timing it started a little easier...

cooper warr

I have this same problem, did u ever figure out the issue

3pedals

iTrader: (3)

Yes and no.
I tore down the engine at the end of 2011 to build a new n/a motor, and found that the cam was advanced 1 whole tooth(works out to 16* @ crank). That puts the front cam sensor beyond its range to read properly.
That could have caused it.....
But I won't know, because I put in a new engine.
The same 6012 box worked perfect with the 11:1 n/a 6.0

The stunningman

iTrader: (47)

Buried in all the answers above. If you have the proper harness that goes down to the oil pan level on your front cover it should be plugged right in. If you don't have the extension harness and plug the MSD cam sensor connection straight into the cam sensor the two outside wires need to be switched.