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Author Topic:   how to test coil/module
sc1 racing
Dirt Freak

Total posts: 419
posted June 18, 2005 01:09 AM  
what is the best way to check your module or coil, and what resistance should it have?

car was running great then back fired and died. only thing i checked was to see if it was firing which it wasnt. distributer isnt broke, no lose wires.

Dirt Forum Champ
Total posts: 968
posted June 18, 2005 05:02 AM  
Is the distributor turning? Spin the motor over with the cap off and check that first. Sounds to me like it has jumped time. Could be a broken distributor drive gear, a broken timing chain, or a chain so sloppy that it allowed itself to climb up one or two teeth.

sc1 racing
Dirt Freak

Total posts: 419
posted June 18, 2005 12:52 PM  
checked allthat distributer turns, put at top dead center distributer lines up perfect.

just will not fire at all..thank you

Dirt Full Roller

Total posts: 26
posted June 18, 2005 07:53 PM  
ignition module in the distributors gone out... it will have power at the supply for the distrib tut wont send power thru to the plugs.

Dirt Forum Racer

Total posts: 98
posted June 18, 2005 11:19 PM  
Make sure your power wire has fire to the distributor. If your not getting fire to the HEI it won't fire. If it is I would say your coil went out.

sc1 racing
Dirt Freak

Total posts: 419
posted June 19, 2005 01:38 AM  
it was the coil replaced it and ran better than ever. must have been weak for the last 3 or 4 races but it came alive tonight..

Dirt Full Roller

Total posts: 38
posted June 20, 2005 10:33 AM  
Just food for thought here... The most common thing that kills coils and modules on a race car is welding on the chassis without disconnecting the battery. We even go so far at to pull the cap and coil off the distributor (which disconnects the module). Now current cannot flow through any part of the electical system.
In our experience (we test and build high performance distributors) coils and modules rarely "get weaker". They usually work, or they don't. The most common thing we see on distributors that won't fire is water in the cap. When you wash your racecar you WILL get water in the cap (under the coil). How? Condesation. Most racers fire up the car, drive it around, do a burnout to impress the hot chick across the street, and then park it to wash it. Now the motor is hot, the distributor is warm, and you are dumping cold water on it. The water condenses in the hot distributor cap, and like magic you get water in the distributor. This will kill a motor everytime. Wrap the distributor in a plastic bag and keep the hose away from it.
Also make sure you intall a ground strap in the cap when you replace the coil. If you don't it will run very poorly or not at all.

Dirt Freak

Total posts: 461
posted June 20, 2005 01:02 PM  
Here is the quickest way to tell if your module went dead at the track or at home. When you spin the motor over the tach will jump around when the module went dead the tach wont move

This dont do anybody any good if you dont have a tach but for those smart enought to run a tach it does

sc1 racing
Dirt Freak

Total posts: 419
posted June 20, 2005 11:27 PM  
i am still wondering the way to test the coil/ module on the bench. id like to know the required resistance that way i could catch it in time before it happens on one of our other cars thank you

Dirt Newbie

Total posts: 2
posted June 22, 2005 08:53 AM  
We had the exact problem. Maybe there is a bad batch of coils out there. Our car ran fine, coil was brand new. Then died and wouldn't start again. We borrowed someone else's distributor that had a brand new coil in it, same thing. Bad coil. Third coil worked like a charm.


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