Msd Troubles


Jun 10, 2013
Hi all, I'm having a problem with my 90 GT and wondering if anyone has seen this. It has an Anderson PMS system, and an MSD 6BTM, and Vortech t-trim running about 15 psi. For many years this all worked great and was super reliable, but now it keeps burning up TFI modules. Other than the 6BTM the rest of the ignition is stock. One day the fuse to the 6BTM popped and the car stalled, so I plugged the coil back to the stock connector to get home, (engine is way down on power and breaks up bad around 4500 rpm without the MSD). Fixed the fuse, now it keeps eating tfi's! I tried a new stator, didn't help. Runs fine when it runs. My best guess is that the 6BTM is the problem, but at $400 for a new one I'd like to know for sure. Thanks in advance for any advice.
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Whole ignition system is stock other than the MSD which tee's in at the coil connector, and 9mm motorsport wires. I have an engine harness and distributor from an older F-150 with remote TFI. I'm going to get the heat sink to mount the remote type TFI on the fender, and maybe just bite the bullit on a new MSD box.
It's just above where the stock air box would be. I think it's cool enough. It's 16 years old and has about 60k real hard miles on it. I wish it would just stop working altogether, at least then I'd know. I'm going to be doing a major tear down on the car pretty soon, one of things I'm doing is moving the battery to the back, so I'm thinking ill mount the new MSD and TFI on the drivers side inner fender.
No I haven't. I have a PMS system in it, and if I remember you're supposed to unhook it from the PCM before pulling codes. It's tucked away in the garage but I'm going to bring it down to my shop in a couple weeks.
I have the old system, it gives you some live sensor data but no freeze frame or anything. The thing is when it runs it runs fine, but then it will just shut down. Sometimes plugging the coil back into the stock connector will make it run to get home, otherwise it burns out the TFI. I'm making my own remote TFI setup using F-150 parts. It needs motor work, so if I'm going to the trouble and expense of fixing it I'm just going to put a new MSD for piece of mind. This one lasted a long time, I don't feel like it owes me anything. That's true of the whole car actually, this year makes 20 that I've had it, and we've had some wild adventures with it!