Misfire at low RPM
 

I have a problem with my car misfiring at a low RPM. from about 1500 to about 2500 it misses. Once you ecxeed the 2500 it lines out. I have a 302 crate engine bored out to a 306, MSD 6al, 70mm T.B., off road X pipe, pullies, mac equal shorties, cold air intake, and 3.73's. I thought it was the itming, so I took it to a local speed shop and when they adjusted the timging, it did nothing. After I left the shop, it got worse. I replaced the cap and rotor along with the plugs, and now I am back to where I was. Any suggestions would be greatly appreciated.
This started after I installed the MSD, x-pipe, and the throttle body.

Did you install the msd, x pipe, and throttle body at the same time? With all three of those mods, it could be any of them. Without knowing your car a little better, it is hard to pinpoint which one it would be. What did the speedshop set your timing at?

I hate to say it again, but if wires #5 & #6 are touching at all, that could be your problem. It's worth the time to separate them.

Take care,
-Chris

I agree with PKRWUD on this one. Those are things that most people don't take into consideration. I would try that first before anything. If your timing is off even more it's gonna miss or backfire like crazy at low rpm's. Also, check the msd on that car. MSD has had some problems with that.

Eric

My timing was set to 14 deg.

How would I go about checking the MSD to see if it is acting up? Disconnect it?

Yes just disconnet it and see if it's getting any spark to the number 5 and 6 cylinders.