Tachometer running high and jumping

[77dino]

My 80 Spider 2000 was not getting a spark and knowing that much of my ignition system was old I purchased a new coil, ignition module, pick up assembly, button, cap, and new spark plugs. After assembly my car is getting spark and runs, but seems to be missing and the tachometer is crazy.
So I am thinking that I have something put together incorrectly although I double checked my wires on the coil and they looked ok. The Tec is running very high and is jumping and when I am running at faster speed I noticed a miss fire or what feels like a miss fire. Any thoughts would be helpful. Thanks

Scott

[vandor]

Did you adjust the magnetic pickup gap?
Some people who had jumping tachs have found that adding a 0.68 uf 400V capacitor to the negative side of the coil fixed it.

[spider2081]

You could disconnect the tach from the coil and see if the tach is causing the misfire.

[bradartigue]

My 80 Spider 2000 was not getting a spark and knowing that much of my ignition system was old I purchased a new coil, ignition module, pick up assembly, button, cap, and new spark plugs. After assembly my car is getting spark and runs, but seems to be missing and the tachometer is crazy.
So I am thinking that I have something put together incorrectly although I double checked my wires on the coil and they looked ok. The Tec is running very high and is jumping and when I am running at faster speed I noticed a miss fire or what feels like a miss fire. Any thoughts would be helpful. Thanks

Scott

Crazy tach (that wasn't crazy before) usually means your new pickup wires have frayed inside the distributor. Common, because the replacements have wires are 3x too long. Check there first.

[77dino]

Thanks I will look at the pick up tonight.
Scott

[77dino]

It is the pickup and the wire is frayed. Any ideas on how to keep this from happening when I put a new one in?

[narfire]

Any ideas on how to keep this from happening when I put a new one in?

Nope, not really. They all fray and become brittle with time.
Careful when putting it back together as the wires can get caught under the cap.
I'll, carry a spare in the trunk with a shorty 17mm wrench and screw driver.
Chris

[77dino]

I have a question. How do you adjust the magnetic pickup gap? Because of it screwing in place it seems not to have any adjustment in it. Thanks
Scott

Did you adjust the magnetic pickup gap?
Some people who had jumping tachs have found that adding a 0.68 uf 400V capacitor to the negative side of the coil fixed it.

[bradartigue]

If the wires are long (most replacement pickup wires are too long) I usually do one of two things:

1) cut them and splice with tiny butt connectors, you can find these at some electronic stores.
2) there are usually two little holes in the distributor base and I've wire-tied them down.

In either case you need to leave enough room for the thing to move. Easy enough to bench test.

I believe the advance plate can be moved by loosening the screws, increasing or decreasing the gap, but honestly can't say I've ever paid much attention to it on the electronic ignitions.