I am having some issues with my car and I don't know what else to check. I have a 2000 trans am, ls2 6.0, 24x reluctor wheel, msd 6010 box. First my problem was the backfiring through the carb and out the exhaust. I replaced the cam sensor and put new plugs in (NGK BR6's, gapped at .040). The car was a little easier to start after that, but would still back fire occasionally. One night I had the car running and it sounded perfect, took the car for a spin, and realized I had a slight oil leak. I fixed that and tried to start the car again and no luck. It would back fire and when I finally did get it started it ran like crap. I contacted MSD and they said I have a bad box, so I sent it back and got a new box. I just put it in the car yesterday and the problems are even worse. I have went through 3 cam sensors, my plugs continue to foul out, due to all the back firing. I have to pull those things out and clean them up all the time, and anyone that has an F-body, knows what a pain in the *** they are to work on, due to limited space. When the car finally does start, it is missing really bad. It will not find top dead center.
I have literally done just about eveything you can. I have taken the front of the motor back apart, just to make sure everything was dialed in right. I have taken the valve covers off, just to make sure the firing order was right.
Installed 3 different cam sensors with the 1K-1/2 W resistor bridged between the A and C pin (and yes they are swapped around like they are supposed to be). Checked power supply and grounds. Bought a brand new battery. Bought new MSD spark plug wires. I don't know what else to do. Why is it having a hard time starting, and when it does start, why is it missing so bad?
Any help would be appreciated. Thanks in advance

 

Try the crank sensor? What color is the crank sensor? Does the car have a cam? What cam gear is in the car?

 

I have not tried the crank sensor, although I was going to test that tonight. I bought a new double roller timing chain from jegs. It has the half moon, magnetic pick up for the cam sensor to read.

 

are you running the right length pushrods?? not a fraction too long?

 

That is why I asked about cam.

How did you run the cam position? With the GM harness or without? Gm harness corrects the hook up for a 6012, an have to have the wires swapped on the outside but for 6010 I am not sure. You may have had to extend the cam position I imagine, so that may have me wondering, my gen IV 5.3 ran like you described till I swapped the wires, you say you did but is that as MSD directed?

 

Just a thought. Make sure you have the coil harnesses plugged into the right banks.1,3,5,7 on driverside and 2,4,6,8 on passenger side.

 

Somebody had an issue like this not too long ago that turned out to be a bad crank sensor.

Another guy had something like that and it turned out he was powering the MSD box through a ballast resistor that was not energized during crank.

So make 100% sure you have full system voltage (13V+) to both the MSD box and the coils while in run or crank. You said you already checked grounds but measuring volts from the box ground wire out to ground will double check that.

As for the cam sensor, you actually don't need it for the car to run. According to the MSD site disconnecting the cam sensor means you have a 50-50 chance of it starting up and running right or being completely out of phase. Not sure if that info is helpful.

You know you could have carb issues too. What do your AFR's look like?

 

Before I get into what MSD said I will answer everyone's questions. My AFR is right around 11.5 at idle, so its pretty good. THe pushrods are the correct length, and MSD directed me to switch the A and the C pin on my cam sensor harness, as well as put the 1 K - 1/2 W risistor bridged between the A and C pin. I talked with MSD for about 2 hours last night and went through every trouble shooting method you can think of for that box. I checked to make sure the the cam/crank sensors were sending signal back to the box, spaced my cam sensor out with a washer about 1/8 inch, traced every wire out, etc. When I did get it started #2 and #6 were running cold, so I flipped the 2 and 6 cylinder pins in the harness, thinking that it was wired wrong but still nothing happened. The next thing I did was drilled the rivets out on the box and opened it up. We checked all the wiring and MSD said it was correct but they would send me a new box in exchange for that one. I don't think they really know what is going on and they just keep sending me boxes until it works. I am going to get a new crank sensor after I get back from the car show and try that as well, but MSD says that the crank sensor is good.
I was really hoping to get to the Ocean City, MD car show this week but its not going to happen now.

 

Hey Zones,

Is this the GM harness you're speaking of? Or is it wrapped into the main engine harness?

 

Yessir, that is The one, if you have that, no need to swap wires. If it is not there, you have to swap the outside two cam position wires per MSDs instruction.

 

Thanks much, I feel better now! One less thing to d!ck around with.

 

I am goin to do a pretty large write up just to clear things up and sticky it one day.