MSD Pro Billet 8365 Distributor Trouble

[Zoom45]

We have a 604 crate and use the MSD pro billet HEI 8365 distributor with the module that has the adjustable rev limiter in it. It ran fine last year and one race this year. It started shutting down a couple of times during a race or while just sitting there idling and now it quit (could have jarred it hitting the wall once) and I can't get spark to the plugs. I put the MSD cap, coil and rotor on my chevy truck and it ran fine so that rules out those parts. I put a new module in it but still can't can't get it to fire. It has battery voltage going from the switch to the cap. It originally came with the 83645 module but the replacement now is an 83647. Is there something else I'm missing? I ohmed the pick up and it says 820 which is withing the MSD range.
Thanks,
Zoom45

[rusty9cab]

If you have not already, make sure it is getting power. I have had ignition toggle switches fail. They sometimes start to slowly before they go out.

[Egoracing]

Sound like it may be a bad ground to the engine.

[Zoom45]

I read that on the MSD forum so I ran an extra ground wire from the center terminal on the cap (ground) to the frame but still no luck. I have a new MSD module and the cap, rotor and coil were put on my truck and it runs fine. My last option is to try a new pickup coil. It reads 820 on the ohm test but could there be a problem with the magnet not sending the signal? That's the only thing I can find left to replace. MSD says that's a standard GM pickup coil. What year vehicle should I ask for to get the right coil?
Zoom45

[Egoracing]

Most ignition issues are gorund related. You should have a wire ground from the battery to the engine, steel is a HORRABLE electrical conductor.

[Zoom45]

I did all that with the grounds still no luck. I replaced the pickup coil too. Only thing I can think of now is the new module is bad. MSD tech was off yesterday for a car show so I'll have to try them next week.
Zoom45

[ep33510]

Zoom45


You might be running into the Traction Control Detection circuit thinking it sees something and putting the module in limp mode. If its not the grounding issue this just might be what your seeing with your HEI setup.

ep33510

[Zoom45]

Zoom45


You might be running into the Traction Control Detection circuit thinking it sees something and putting the module in limp mode. If its not the grounding issue this just might be what your seeing with your HEI setup.

ep33510

Not sure what to check on that issue. I talked to MSD tech this morning and he said to run a ground wire directly from the neg side of the battery to the distributor. I did that and nothing different. He also said to ensure I have at least 10 volts to the distributor while cranking. I have an Optima red top battery with 12.30 volts. When I start cranking it reads 10 at first but it drops to 8.73 after long cranking. Maybe it's losing some through the switch. I did disconnect the gray wire (on the new module) from the tach and the car started up. It ran long enough to let me adjust the distributor for a good idle then it shut off just like you turned the switch off and it won't spark again.

[Zoom45]

I finally figured out the problem. I'm not getting full battery voltage to the bat terminal on the cap while starting. It's losing voltage through my ignition switch or the wiring. I took my boat battery and connected it directly to the battery terminal on the cap (by-passed the car system) and if fired right up. MSD tech said the distributor must have at least 10 volts to the cap while cranking. I'll change the switch and ensure my Optima battery is maintaining it's charge and should be good to go.
Zoom45

[9WRACER]

check the battery and make sure its not shorted internally, had one do that after a crash, plates short out and loose voltage

[Zoom45]

He did slap the wall early this year so I will load test the battery. I found the ignition switch had 4.5 ohms resistance and a new switch was only .3 ohms resistance. I replaced the switch and wiring and it cranks up fine. It wouldn't crank even with a hot battery connected with jumper cables. I guess it wasn't getting through the switch. I always seem to get these weird problems. LOL.
Zoom45