Just cranking

[raider65]

Got a problem...I got in my truck started her up and put it in reverse, i released the brake and barely touched the gas pedal and it shut down. The truck just cranks but does not turn on. Got gas squirting in the carb. I'm thinking HEI coil..changed that out and still nothing?

[storm9c1]

Ignition module could be bad. Or carbon button above the rotor. But first I would pull a spark plug boot, use an old spark plug and snap it into the boot. Then rest it on an area of clean metal or clamp it. OR stick a screwdriver in the boot, lay it close to something metal like the frame. Try to get a 1/8" gap or less between the screwdriver shaft and metal. Then have someone crank it while you watch. If you see no spark jumping, yep, it's either a bad ignition module or the 12V power feeding the distributor. If you have a multimeter or a test light, you can also test for power at the distributor to make sure you are getting 12V with key in the run position.

I assume that when you had the cap off to replace the coil you checked the rotor? I've had the screws fall out of the rotor before. Rotor sits still while the arm spins under it! It's easy to miss that little detail.

If you DO see a spark, try another cylinder to make sure the rotor is moving. If timing chain broke, you have a 1 in 8 shot of picking the spot where the rotor landed. LOL.

There are lots of things that would result in a no-start such as a fuel problem or timing chain broke, bad cam, something like that.

[68gmsee]

Yeah, definitely check for spark. Easiest way to do it is to use the timing light clamped to the spark plug cable (any cable will do).

If no spark, the HEI module would be the next suspect as mentioned above.

If you do have spark and truck is not flooded, suspect timing chain. I had one jump several teeth once and threw timing way off. You can check that by the "finger in the hole" method of checking for #1 piston on top of compression stroke and making sure timing mark on harmonic balancer line up to "0" or TDC.

[Marv D]

Wiring problem would be my first suspect. Then fuses, then HEI module, then cap and rotor,,,,,,,

[Gumby]

I always grab the starting fluid, if it won't even POP on that, your spark is bad. [ even if you see one ]

does try, its fuel or bad timing.

[storm9c1]

Originally Posted by Gumby

I always grab the starting fluid, if it won't even POP on that, your spark is bad. [ even if you see one ]

does try, its fuel or bad timing.

Yep, good suggestion too. If starting fluid isn't laying around, Gumout carb cleaner spray works too (but only Gumout, other brands may not run the motor whereas Gumout does).

You can also dribble some gasoline down the carb. Forgot about that trick too... I usually don't suggest it because if done wrong can result in a flaming fireball.