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So I decided to go to work in the Speedster today. After over 20 miles into the trip on the freeway the car started missing and losing power while the tachometer went nuts; the needle was all over the place and not reading correctly. When I came down the ramp the car backfired a few times and was missing with almost no power. Thank God I made it to the office but now I’m 40 miles away from home. We let the car cool off and it worked fine at first but the more it warmed up the worst it got. The idle is not smooth anymore. Some have suggested checking the spark plugs first. I wonder if my Pertronix module comment a few weeks earlier in another post (where I said that I heard Pertronix modules were trouble free once installed) came back to bite me. The tachometer being crazy is a totally new symptom; ever since it was re-gutted with VDO innards by North Hollywood Speedometer many years ago it has never given me a problem. I suspect electric gremlins in my car’s wiring. Any thoughts from the brain trust here? Have any of you experienced something similar?

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" I wonder if my Pertronix module comment a few weeks earlier in another post (where I said that I heard Pertronix modules were trouble free once installed) came back to bite me."

I have never heard that Pertronix modules are "trouble free".  I have heard about too many Pertronix modules going belly up to ever believe that in both Speedsters and Hot Rods.  They truly are heat-soak sensitive and degrade at a premature rate, giving the same symptoms as you've seen, especially the weird tach.  If you swap it out for a new one, get two and keep the other in the Frunk as a spare.  They're easy to swap on the road - Done that a couple of times at Carlisle.

I would be REALLY surprised if it was the plugs or coil.  The coil AND tach get their signals from the Pertronix.  

I would NOT be surprised at all that the Pertronix module is toast.

Last edited by Gordon Nichols

The absolute first thing you do: Pop the cap and rotor. Remove Pertronix. Clean the bottom(steel wool, sandpaper, etc.), clean the heck out of the distributor where it bolts down. Clean the screw. Re-attach, you can use a nice star washer on the screw to make sure the connection stays good.

Dozens of people have this problem and try to fix it by throwing parts at it. Try this first, then buy me a beer some day in thanks.

Larry Jowdy(rest in peace) "fixed" a bunch of Speedsters and Spyders out in California with this fix, probably a dozen.

Last edited by DannyP
@DannyP posted:

The absolute first thing you do: Pop the cap and rotor. Remove Pertronix. Clean the bottom(steel wool, sandpaper, etc.), clean the heck out of the distributor where it bolts down. Clean the screw. Re-attach, you can use a nice star washer on the screw to make sure the connection stays good.

Dozens of people have this problem and try to fix it by throwing parts at it. Try this first, then buy me a beer some day in thanks.

Larry Jowdy(rest in peace) "fixed" a bunch of Speedsters and Spyders out in California with this fix, probably a dozen.

Good to know; thank you for this.

@DannyP posted:

The absolute first thing you do: Pop the cap and rotor. Remove Pertronix. Clean the bottom(steel wool, sandpaper, etc.), clean the heck out of the distributor where it bolts down. Clean the screw. Re-attach, you can use a nice star washer on the screw to make sure the connection stays good.

Dozens of people have this problem and try to fix it by throwing parts at it. Try this first, then buy me a beer some day in thanks.

Larry Jowdy(rest in peace) "fixed" a bunch of Speedsters and Spyders out in California with this fix, probably a dozen.

Danny; we have a winner!! The module base was loose. All I did was tighten the screw of the baseplate and then reinstall the module setting the gap to .035”. Pertronix recommends .030” but Ratwell recommends leaving as much gap as physically possible without affecting the advance mechanism by rubbing against the distributor body:

https://ratwell.com/technical/PertronixAdjust.html

I went conservative but the car worked fine and I drove back on the freeway. I will now go over the spark plugs, timing and carb adjustments as suggested earlier by you guys.

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