How can I check out a coil?

Old 02-04-07, 06:10 AM
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Question How can I check out a coil?

I have a 87 Chevy full size blazer, 305 ci, 4X4 plow truck. I plowed the driveway last week, ran fine. Parked it, needed to plow again, now it won't start. Last week the temps have been above freezing durning the days and then dropped below freezing at night. This week the temps are in the single digits, 10 to 25 mph winds, and wind chills in the double digits. Could I have gotten condensation in the gas tank, and now being so cold, a gas line freeze up? And being so cold out, how would I get it to thraw, I don't have a garage.
I also wanted to check for spark to see if maybe the coil went bad. Can I take the coil wire off the dist cap, put a wire tested in the end of the coil wire, crank the motor and see if my wire tester lights up? Can I test it that way? I know the coil wire is good, just replaced all the wire 3 weeks ago. I also know the fuel pump is working, I can hear it running. Any ideas?
Old 02-04-07, 07:28 AM
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I'd start with:
Autozone site with model-specific info on checking things out.
Check fuel delivery (carb or injectors?; if carb, could be choke hanging up?; if injector: usually is some port on fuel rail that you can take cap off, energize fuel pump, depress pin in center of port, fuel should spray out[make sure no open flames or other sources of ignition when you do this; have a rag handy and protect eyes etc...]); spark at plugs (take one out, leave wire on, make sure base is grounded well and crank engine to see if spark in plug gap), air- you likely have this.
Good luck!
Old 02-04-07, 08:00 AM
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Blazer won't start

Just a little variation on checking for spark. Get another plug,remove wire and connect to it. If you remove a plug and the motor is flooded when you crank it over it can expell the gas and if there is spark, you know the rest. If you don't have spark don't over look the module in the dist. Ive had them do this same thing.

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