I need to change my pickup coil on my 86 Duke. I have the procedue down, but what exctly does this mystery coil do? Just curious.

Curly

Hmmmmmmmmmm never thought about it

That was odd. I posted a reply, and it disappeared.

Anyway, the pickup coil sends reference pulses to the ignition system. Those reference pulses are used to determine when to fire the ignition. The basic function is similar to the crank position sensor in a DIS setup.

I see, makes sense, mine is apearantly burning out my ignition modules. It will eat one evey three days. It's the one part on my distributor I haven't replaced yet. Thanks for the info.

Curly

They act like the old points/condenser on the older ignitions.
The pulses are what triggers the ignition coil for spark, is used by the ECM for triggering injector pulses, it is used with the ignition module for controlling the timing advance, and provides the pulses for the tach.
A pick-up coil could kill an ignition module and visa-versa. It is usually better to replace both at the same time.

quote Originally posted by Blacktree: Anyway, the pickup coil sends reference pulses to the ignition system. Those reference pulses are used to determine when to fire the ignition. The basic function is similar to the crank position sensor in a DIS setup.

On a DIS system isn't it the cam sensor? If I recall the crank has 3 magnetic spots 120* apart and the cam has 6 magnetic spots (on the V-6's) for the TDC of each cylinder.

[This message has been edited by Oreif (edited 01-30-2009).]

Same happened to me, posted a reply and nadda? No biggie. As always; Orief provided the correct info. BTW: there are lots of dif types of pickups, magnetic, optical but all serve to get rid of machanical switches.

For the fellow eating picks read the file below and you will likely stop buying pickups:

Your’s could be a common problem and don’t cost anything to check.
Try this:
Watch the tach when cranking if it don’t move you're not getting pulses from the distributor. If so, it could be a faulty module in it or more likely simply corroded connectors at the base of the distributor. Reseating those connectors a few times could clean the pins some and also do the same to the connectors on the coil etc. These cars are old, and old connectors corrode. Such can also manifest itself as intermittent misfires, and engine cutouts.

BTW: lots of folks keep replacing modules and coils thinking they are bad because the new ones FIX the problem, when in actuality the fact that they simply unpluged the connectors and repluged them into the new unit cleaned the contacts enough to make it work again, at least for a while. It's smart, to replace those old connectors with new ones.
BTW: Cliphouse has those connectors

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quote Originally posted by Oreif: On a DIS system isn't it the cam sensor? If I recall the crank has 3 magnetic spots 120* apart and the cam has 6 magnetic spots (on the V-6's) for the TDC of each cylinder.

Note quite. DIS doesn't pay any attention to the cam. The crank has 6 notches (plus a 7th for "synch" to mark each revolution) which generate pulses in the crank position sensor. The DIS brick reads the crank sensor. A 6 cylinder DIS passes every OTHER pulse to the ECM as the ignition reference signal. A 4 cyl DIS brick passes every THIRD pulse to the ECM. That allowed GM to use the same trigger wheels and sensor on 4 cyls and 6 cyls.

They would have had to go to a 12 notch wheel to run an 8 cyl with DIS.

I can’t fathom how your pickup coil could be causing your ignition module to fail.
The pickup coil works like the pickup in an electric guitar, if that means anything to you. The ignition module is a preamplifier to boost the signal, presumably so that it won’t become corrupted by all the electromagnetic noise generated by the high voltage part of the ignition system.
Amplifiers (and preamplifiers) produce heat. In a Fiero, this heat must be transferred to the aluminum distributor plate to which the ignition module is attached. The bottom face of the module must have good contact with the plate for thermal transfer. To help this process, “heat sink grease”, as it is often called, must be applied to the area of contact between the two. It is available from Radio Shack.
Be sure that both surfaces are smooth and clean before applying the goop.
Further, prior to the 88 models, there was a Mickey Mouse fan in the trunk that blew air from the trunk onto the ignition coil and module as well as the alternator in a desperate attempt to keep them cool. For the 88 models this was eliminated. I guess that was because it was found to be ineffective. I don’t know.
Anyway, for my 88 I bought an inline 3inch diameter fan from Pegasus Auto Racing Supplies and 150 degree thermostat (White Rogers 156-1) and installed the fan in the trunk and the thermostat on the ignition heat shield. Plumbing was done with PVC with a 2”diameter line blowing air onto the ignition coil and module. This is similar to the factory system but on enough steroids to kill an elephant.
It is 4 months now since the installation and I have had no problems. Prior, in 6 months I had gone through 2 ignition modules a coil and an alternator. While my system doesn’t blow on the alternator, it has to be improving the general heat situation in the engine room.
I promise to post on this with pictures.

^ a crappy signal.

anyways - yes - like everyone said - it create pulses, used in the timing of the ESC

anyways - if you are popping modules - I too doubt it is the pick-up coil. I would look more at cleaning the dist shaft - maybe it is sticky and the spinning creating excessive heat. a exhaust leak on the y-pipe, or the joint between the y-pipe, and the forward exhaust manifold, creating excessive heat. but - excessive heat is the problem. but - yes the pickup coil, and the igntion coil - they both can become causes for module failure as well, but less likely, being they'd be near failure themselves.