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1990 gmc sierra crank but not starting.

queenzombie13

By queenzombie13
in Ask A GM Technician

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queenzombie13 New Member

queenzombie13

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Im possibly trading my car for a 1990 gmc sierra ext cab truck. Its not running, this boy tells me it has a rebuilt motor which i believe we looked and it looks rebuilt. But the problem is it cranks but wont start, it is getting fuel, fuel pump works, it has a new distributor and module, so could it be the coil? We unhooked battery to reset the computer as well, so just trying to see if easy fix or what.

Doug_Scott Senior Enthusiast

Doug_Scott

Posted
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Has the truck ever run since the rebuild? Did you check for spark at the plugs? First thing to check on the GM HEI ignition is the rotor inside the distributor cap. Take the rotor off, and turn it over to check out the underside. If you see any black on the underside of the rotor near the middle, replace the rotor and try to start again.

 

Anything other than that will require more information from you on what you have checked for, or when did engine stop starting.

queenzombie13 New Member

queenzombie13

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Yes it has ran since rebuild.new cap and rotor i checked that.he kept saying something about a wire.well i looked it over and the wire that plugs into the module was unplugged so i plugged it in and it is getting fuel now and i checked for spark at the plugs and nothing thats why im thinking.so if coil doesnt do it whats next?thnx.

Doug_Scott Senior Enthusiast

Doug_Scott

Posted
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If the module was unplugged you have to ask yourself how did that happen. There is another pair of wires inside the distributor that go the pick-up coil. Fairly common for those wires to break where they come out of the pick-up coil. A gentle pull on the wires will show you if they are broken. You should be able to locate instructions online on how to check the module and how to check the coil using an ohmmeter. I don't recall the numbers, but, it will take you just as long as it would take me to find them.

queenzombie13 New Member

queenzombie13

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By the way are the wires your talking about go into the distributor or plug into the module next to the plug for the fuel.im not going to see it till next weekend so i want to know what all i need to trace down thnx.

Doug_Scott Senior Enthusiast

Doug_Scott

Posted
Posted

Inside the distributor. The module has wires connected at both ends, one end has two wires, that connect to the pickup coil also inside the distributor. Those wires.

When you said the module was disconnected, you were talking about the part that bolts to the base of the distributor inside the cap aren't you? Your comment about fuel when talking about the wire has me thinking we are not talking about the same part.

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