Engine not starting
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New User
Joined: Oct 2013
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Engine not starting
I have a 1986 F250 and today, after having no problems with it starting since I picked it up, it did not start. The starter is cranking, however it will not fire. The carb is not flooded as I took the air filter off and there was no smell of raw gas. That is extent of my ability to trouble shoot as this is my first older vehicle I've owned. I'd like I see if anyone's had this problem before or could steer me in the right direction on where to start. Thanks in advance!!
Laughing Gas
Joined: Nov 2010
Posts: 924
Likes: 4
From: Johns Creek GA
I would start with the fundamentals...you need fuel, air, and spark to make the engine go, right?
Are you sure you're getting fuel? I'm assuming you've got gas in the tank. If you look down the throat of the carburetor while someone pumps the gas (or you work the throttle linkage) you should see squirting gas. If you don't, you could have a dirty or otherwise damaged carburetor, a fuel pump failure, or another fuel delivery problem.
Air....I'll assume you aren't doing this underwater, so that's probably not your problem.
You could have a spark issue, such as your coil being bad or your ignition module being out. Someone else will probably have a better way to test this, but in the past I have unplugged one of the spark plug wires, and held the metal connector near the engine block (while wearing rubber gloves) while someone cranked the engine, to see if a spark jumped.
If you have all of these in order, then it's probably a more complex problem, such as timing, compression, et cetera. Someone smarter and more experienced than me will have to explain how to check those. Regardless, if you take a methodical, step-by-step approach to troubleshooting, you'll figure it out in short order.
Are you sure you're getting fuel? I'm assuming you've got gas in the tank. If you look down the throat of the carburetor while someone pumps the gas (or you work the throttle linkage) you should see squirting gas. If you don't, you could have a dirty or otherwise damaged carburetor, a fuel pump failure, or another fuel delivery problem.
Air....I'll assume you aren't doing this underwater, so that's probably not your problem.
You could have a spark issue, such as your coil being bad or your ignition module being out. Someone else will probably have a better way to test this, but in the past I have unplugged one of the spark plug wires, and held the metal connector near the engine block (while wearing rubber gloves) while someone cranked the engine, to see if a spark jumped.
If you have all of these in order, then it's probably a more complex problem, such as timing, compression, et cetera. Someone smarter and more experienced than me will have to explain how to check those. Regardless, if you take a methodical, step-by-step approach to troubleshooting, you'll figure it out in short order.
Post Fiend
Joined: Sep 2006
Posts: 14,325
Likes: 14
From: Island Southeast Alaska
It takes fuel, spark and compression for an engine to start and run.
One of these is missing or not in enough supply. With the air cleaner off
and looking down in the carb does gas squirt when ya pump the throttle?
Pull a plug wire and hold it a 1/4 inch from the engine block or any good
ground. Crank the engine over. Does it have any spark?
Do this and get back to us please.
One of these is missing or not in enough supply. With the air cleaner off
and looking down in the carb does gas squirt when ya pump the throttle?
Pull a plug wire and hold it a 1/4 inch from the engine block or any good
ground. Crank the engine over. Does it have any spark?
Do this and get back to us please.
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New User
Joined: Oct 2013
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Thanks a ton for the advice guys!! Found the problem! As far as the fundamentals, you were spot on. Had fuel, and spark, but no air!! The butterfly valve on top of the carb was not opening at all! Followed a wire down from where it connected to the carburetor and it was disconnected at a connection. Once I reconnected it, all problems went away. Thanks again for the advice! You guys rock!
Laughing Gas
Joined: Nov 2010
Posts: 924
Likes: 4
From: Johns Creek GA
Trending Topics
Post Fiend
Joined: Sep 2006
Posts: 14,325
Likes: 14
From: Island Southeast Alaska
I would start with the fundamentals...you need fuel, air, and spark to make the engine go, right?
Are you sure you're getting fuel? I'm assuming you've got gas in the tank. If you look down the throat of the carburetor while someone pumps the gas (or you work the throttle linkage) you should see squirting gas. If you don't, you could have a dirty or otherwise damaged carburetor, a fuel pump failure, or another fuel delivery problem.
Air....I'll assume you aren't doing this underwater, so that's probably not your problem.
You could have a spark issue, such as your coil being bad or your ignition module being out. Someone else will probably have a better way to test this, but in the past I have unplugged one of the spark plug wires, and held the metal connector near the engine block (while wearing rubber gloves) while someone cranked the engine, to see if a spark jumped.
If you have all of these in order, then it's probably a more complex problem, such as timing, compression, et cetera. Someone smarter and more experienced than me will have to explain how to check those. Regardless, if you take a methodical, step-by-step approach to troubleshooting, you'll figure it out in short order.
Are you sure you're getting fuel? I'm assuming you've got gas in the tank. If you look down the throat of the carburetor while someone pumps the gas (or you work the throttle linkage) you should see squirting gas. If you don't, you could have a dirty or otherwise damaged carburetor, a fuel pump failure, or another fuel delivery problem.
Air....I'll assume you aren't doing this underwater, so that's probably not your problem.
You could have a spark issue, such as your coil being bad or your ignition module being out. Someone else will probably have a better way to test this, but in the past I have unplugged one of the spark plug wires, and held the metal connector near the engine block (while wearing rubber gloves) while someone cranked the engine, to see if a spark jumped.
If you have all of these in order, then it's probably a more complex problem, such as timing, compression, et cetera. Someone smarter and more experienced than me will have to explain how to check those. Regardless, if you take a methodical, step-by-step approach to troubleshooting, you'll figure it out in short order.
But you spelled it out much better. Reps to ya bud.
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