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Engine won't fire

1

1973K5Blazer

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Wildomar, CA
Ok, I have a 73 350 k5 blazer which has been sitting for about 3 years. I was able to get it to start back in January after some encouragement with fuel and starting fluid. Since then it has been sitting for about 3 more months. I tried to start it the other day and it wouldn't even try to fire. I have checked the plugs, distributor and rotor cap. It all appears to be fine no build up or blemishes. I replaced all components prior to truck sitting. The starter turns but there doesn't appear to be any spark. What is the best way to check this, and any ideas what it could be. Any advice would be highly appreciated.

Thanks
 
to check spark, remove a spark plug, connect it to its plug wire, put on a pair of heavy work gloves, hold the spark plug by the insulated boot so that it is touching the block but you can see the electrode. Have someone crank the engine. If there is spark, youll be able to see it.

you can do this without the gloves, but an HEI gives quite a jolt. not really fun.
 
Does your 73 still have the factory points distributor or has it been swapped for an HEI?
 
British Slave said:
Pull a wire at the distributor cap and have someone crank it while you watch for spark. Hold the wire close to the terminal you pulled it from. It won't bite you from that end.
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Dude, you're kidding right? ANYWHERE there is a high voltage spark it can BITE you.
 
Check for spark, check to see that your carb is delivering fuel when you move the throttle lever, and I'm not sure how old the gas is you're using, but if it's 3 years old I'd get rid of that too.
 
Remove fuel line from carb and insert fuel line into empty pop bottle. Crank until fuel enters bottle. Check carb fuel filter for crud, clean and replace. Reinstall fuel line. Once you have verified you have spark, pull the plugs, squart a little 10W30 motor oil in the spark plug hole, check the spark plug gap and reinsert into the hole ( retighten ). Do it to the other 7 plugs.
If you have spark and fuel and still no start, It may have jumped timing ( chain streched, cam sprocket worn down ).
 
Gas in the tank is quite old, I have added about 5 gallons of new gas from a gas can. When the accelerator is pressed there is some fuel entering the carb. I have also been putting fuel directly into the carb from a gas can. I am curious because it cranks from the started but it doesn't even sound like the engine is trying to fire at all. When I get off today I will check by pulling the plugs and checking for spark. Thanks for the advice guys, everyone is always so helpful.
 
You must remove ALL the old fuel. Gas starts to go bad after 6 months. Pouring fresh gas into the tank with old gas isn't going to do anything except waste 5 gallons of gas.

If you are still running a points distributor you need to check/replace the points and condensor. If it's an HEI then you need to check/replace the ignition module and or the pick-up coil within the distributor. Each of these items could be a cause for no spark. The coil could be bad as well but not nearly as common of a problem as these other items.
 
not to split hairs... but i really would advise against just pouring fuel into the carb (and thus the intake manifold) from a gas can. i could see that going very poorly after a backfire.

instead, if you want to see if the engine has spark and correct timing, disconnect the fuel line from the carb (for the aforementioned reasons) and get a can of aerosol carb cleaner, or gumout. the engine will run quite well on this. spray the aerosol into the carb throttle body while someone cranks the engine. if the spark and timing are good, it will fire right up. if not, then youve got issues other than fuel.
 
British Slave said:
No...Dude I'm not kidding.
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that my friend is not very smart, your lucky you havent been bitten yet.

you can also buy a spark tester which is a plug with a clamp on it so, it attaches to the boot and then clamps to the frame to ground it, if you dont want to spend the money on a tester (5 bucks) then lay the spark plug on the frame and crank from there, it will ground enough to show spark. thats a good secondary ignition chenck.

for primary check to see if your getting power at the connector with the key on, if so and the grounds are good than like 4x4high said, look at replacing the ignition module if its HEI, if points than the coil.

for carb like said before disconnect the fuel like and put in a 1 gal empty milk jug and crank, if no fuel than bad fuel bump,

if fuel then check to see if its making its away to the carb and spraying if so check timing.
 
If you are careless or clumsey, yeah it will bite you. But I don't stick my finger in the terminal on the diostributor. never, NEVER been hit when pulling wire off didtributor. It's basic electricty, don't be the ground. Quickest way to isolate missing cylinder.
 
dosnt mean it wont happen ;) i bet every guy who died playing russian roulette said "ive never NEVER been bit yet....... BOOM!"

not like its life threatening, hell, ive hit myself with a taser once or twice in my life just to see what its like, just sayin, you can get hit by the shock anywhere on the circuit. but like you said, if youre careful the chance is far less. most times ive been hit i was being rushed and careless. fingers went numb for a few, pretty much the worst of it. unless your head is under something and you jump, could cause a hell of a headache :)

in any case, back onto topic, i would check spark first, if you have spark, try running it on carb cleaner or gumout, if it runs on the spray, start looking at the fuel system, if it dosnt even run on the carb cleaner, start looking at your actual timing. bring the #1 cylinder to TDC, and check your dizzy rotor to make sure its pointing at the right plug wire, and the rest of the wires are in the correct order.
 
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