what is wrong? wont start

paint94979

Beer Nazi
Sep 18, 2006
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My dads old work truck shut off and won't start... It's a 93 1500 Silverado 5.7l. Ignition coil? What's the easiest way to diagnose?
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
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Does it have fire is the 1st check. Coils on those do fail, but the ignition module can also go out and cause a no start. I don't have the ohm readings for the coil on this laptop, but you can find them online.
 

MACKIN

Smell My Finger...
Aug 14, 2006
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Sometimes ,not allows,that if it sparks after you crank and key off it is probably the module. Seen that a few times
 

beanpole209

New member
May 5, 2010
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Are you sure it doesn't have spark? I always just try starting it on ether to see. The fuel pump, module, or cp's are the usual suspects.
 

paint94979

Beer Nazi
Sep 18, 2006
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Another thing is when the truck was being lugged going up slight grades the truck would start to miss. Has 50k miles on engine and 25k on trans should inline with a possible coil?
 

S Phinney

Active member
Aug 15, 2008
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Another thing is when the truck was being lugged going up slight grades the truck would start to miss. Has 50k miles on engine and 25k on trans should inline with a possible coil?

Could be coil rotor button and cap or reluctor wheel and crank position. Remove crank position sensor and see if the reluctor wheel will move or is broke. Very common problem with the engine.

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beanpole209

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May 5, 2010
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Whats the pressure though?

If you fog it with ether, it will eliminate 1/2 of possible solutions. If you go to a parts store and have them test the module, then you just eliminated that as well. though, many times the module will start back working once its cooled off. Otherwise check the things above, and get that three fitty going lol.
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
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Could be coil rotor button and cap or reluctor wheel and crank position. Remove crank position sensor and see if the reluctor wheel will move or is broke. Very common problem with the engine.

Sent from my DROID RAZR using Tapatalk 2

93 doesn't have a crank sensor in it, it's all through the distributor.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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do this nick

untitled-5_zps2986dcd0.jpg


let us know what it says
 

btfarm

you know
Nov 25, 2010
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The module is a flat black piece in the distributor bottom with a 2 flat connectors on each end. It's held in with a small screw with a 1/4" hex head (maybe 2 of those). You'll see it when you take the cap off. This could also be the pole piece. A ring around the distributor shaft in the housng bottom if it's an HEI distributor.
 

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THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
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For a 93 it uses the 7 pin module in the distributor. If it has no spark while cranking then it is either the module or coil. The ECm has no control of spark below 250 RPM's. During cranking the module fires the coil, and at 250 RPM's the internal switch transfers timing control over to th ECM. Heres a pic of one.

getimage.php
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
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Ah. I thought '93 still had the old HEI setup and it changed in '94 with the Vortec. My bad.

GM did away with the old style HEI back in the early 80's for almost everything. They stayed with the HEI for awhile, but it was a ECU controlled for timing unit, and in 87 in the trucks they went to the small cap with full ECU timing control when running. now if it was losing spark after startup that could be a bad knock module or ECU, but no spark during cranking is normally a coil followed by ignition module so long as there is 12V+ power at the coil.