Engine firing

[1973K5Blazer]

Ok, so I have new ignition coil, distributor cap, rotor, plug wires, spark plugs and still can't get my truck to fire up. Used an electrical tested and on all connections the light lit up, I place tester to the top of the ingnition coil (the connection from top of coil to ditributor) and no light. With the ignition on and in teh start position no juice. This is a brand new coil and I'm not sure if this should light up or not. Any help would be highly appreciate. After 2 years without my truck running I am getting prety sad. Thanks!!!

 

[73k5blazer]

You shouldn't get a light there, that's not 12v, it's 20-100,000volts depending on the coil, it won't light a standard 12v light.

With everything hooked up and the engine turning over, have you done the spark plug test? The old standard remove a plug, connect it to the wire and ground the plug while you turn it over and see if you can see a spark?
Is this still an old style points dist or did you put a newer HEI distributor in? If it's points, have you adjusted those properly? Some of the other internal distributor parts go pretty easily on those points ones too.

Go look at the free "Repair Manuals" section of autozone.com (I think you have to register now, but it's free). They have a bunch of tests you can run on your ignition system to narrow down where the problem is.

 

[80' 427]

hei also has a pickup coil and a module that can go bad.

 

[K5dreamer]

you got four things that have to be right for there to be fire and thunder.

Air/Fuel/spark/timing.

I check em in this order......

Spark - make sure you got it. Get a leather work glove, pull a spark plug, connect the plug wire to it, and put on the glove. Hold the spark plug in the gloved hand, and touch the threads to the exhaust manifold. have a friend crank the engine and watch for the spark. It should be white with a blueish tinge, and easy to see even in daylight. obviously its easier at night. If you have spark.... proceed to step 2. If you dont have spark, its time to start figuring out why. But worry about all that jazz after these four things.

Timing - sounds simple enough, but making sure your timing is spot on is critical. Youd be surprised how many times ive had a guy tell me he was sure the timing was right, and he hadnt messed with it, and it ran before and all that other jazz, and when i reset the timing it fired back up. get yourself a piston stop, or a long bolt with the same threads as a spark plug, and very gently rotate the engine around with a breaker bar so piston 1 is at TDC. youll need a little trial and error here, as you want to rotate the engine until it hits the bolt, back the bolt out a little, rotate the engine, back the bolt out, rotate the engine, back the bolt out, until the engine rotates past TDC. then rotate the engine back, screw the bolt back in a turn, and rotate the engine until it taps the bolt, now youre at tdc. Of course make sure this is TDC on the compression stroke. to do that, rotate the engine with your finger over the spark plug hole, and feel for the air pressure of the compression stroke. when the air pressure stops building, youve reached TDC. Now, pop the cap off the dizzy, and make sure the rotor is pointing to that #1 cylinder, if not, adjust the dizzy as necessary. now timing is on. step 3.

AIR - take the air cleaner off, just to me sure a clogged air filter isnt starving the engine of air and causing an overly rich mixture which wont light.

Fuel - you can have too much (rich mix on the carb) or to little (clogged fuel line or filter, lean mix on carb). Gotta find that baby bear setup. Contact the manufacturer for the process to adjust your carb, it varies. There should be a method for all of them to "baseline" adjust them to start the car.

If it still wont fire up...... get a case of beer and a buddy who knows more about the contraption than you do

 

[chulisohombre]

^^ x2 ^^ buddy who knows what to do and some beer will help.first check the simple things as was said in above post.check input power.if it was switched to hei,did you take out the fusable link wire to the original dizzy and change it out with a regular wire.if you still have points, have to be preset to i believe .038 for normal apps.about the width of a match book lid at full openon the cam.adjust accordingly.otherwise check for good fuel pressure and carb hooked up right as preadjusted correctly.let us know what it does.