Help 351 won't fire?
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Freshman User
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Help 351 won't fire?
I have a 351 that won't fire, it's got a new carb, fuel lines, cap, wires, plugs, new brain box on the drivers side. I pulled it out of the garage and it died now won't even try to start on starting fluid? Don't have any help to check spark but I'm assuming that's what it is. I replaced the brain box with no luck?m
Post Fiend
Joined: Dec 2006
Posts: 9,111
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From: Lexington Mo
It would be nice to have another person there to help. But you could take off the distributor cap, and see if the rotor is turning when the engine is spinning. That would at least tell you that the timing chain is still intact.
Have you checked for 12 volts at the ignition coil
.
Unk Bob
Have you checked for 12 volts at the ignition coil
.Unk Bob
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Freshman User
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So it's got 10v while cranking but I can't see the cap while turning it over right now. The battery is a bit low but should still fire I would think. The brain box doesn't have to bolt and grounded does it? Also it just pushes voltage to the distributor right? So the box should be good?
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Ya it's getting fuel, also has new fuel lines and pump. I can see it dumping in the carb. I let it rip with starting fluid without hitting a beat. Bolted the box down and put a new solenoid on it here a second ago and found a blown fuse for eng sol. ? Don't have any of those long ones so I made a shorty work but still no luck 
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Should I pull the carb and dump fuel directly in? Maybe the carb is clogged from replacing everything. Filters look clean though, you would think it would still fire on starting fluid though right?
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Elder User
Joined: Feb 2014
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From: british columbia, canada
Why are you using starter fluid? that is for big diesels on very cold days. Stop doing that. If its getting fuel then it must be an electrical issue.
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Fleet Mechanic
Joined: Dec 2007
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From: Wildwood Pa
Replace the pickup coil in the distributor.
There are ways to test the ignition system if you have a multimeter. Do a search online for testing the Duraspark system.
Don't remove the carb & dump gas in it.
Pull the plugs & clean them, they are probably gas & ether soaked.
There are ways to test the ignition system if you have a multimeter. Do a search online for testing the Duraspark system.
Don't remove the carb & dump gas in it.
Pull the plugs & clean them, they are probably gas & ether soaked.
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Freshman User
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I'll give that a shot guys thanks so much for the help. I wasn't sure if I lost prime from swapping the lines, carb, pump, flushing tank out. I only let it run for a minute before I pulled it out of the shop so I thought it list prime and couldn't reach my compressor to push some air
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So every plug has spark all the way to it. I did figure out one very odd thing... it starts now.... but only with the plug out and grounded? I put the plug back in and won't start. Pull a different one and ground it on the carb and it starts... I did notice it only starts when you let off the key also.. blowing my mind right now
Post Fiend
Joined: Dec 2006
Posts: 9,111
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From: Lexington Mo
Make sure that you engine block is grounded to the body. There should be a ground strap that goes from the back of the intake manifold, straight back to the firewall.
The stock strap should look like this one.
Attachment 206322
On my 79 I have the engine grounded to the body, and to the frame both.
Unk Bob
The stock strap should look like this one.
Attachment 206322
On my 79 I have the engine grounded to the body, and to the frame both.
Unk Bob
Post Fiend
Joined: Apr 2002
Posts: 19,311
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From: Waterloo, Iowa
Bad ignition switch can cause this iirc, someone will remember better than I. Symptom is only sparks when going from "Start" to "Run". Aggravating I bet.
Keep in mind that not just any ole' spark will do. It has to be a fat, healthy spark. Orange or reddish won't work, it won't jump the gap when actually installed in the engine and under compression.
An engine that won't start is real rough on all the components, solenoid, battery, starter. If it does finally start, it will then torture the alternator. Put the battery on a charger at let it cook at least overnight.
Keep in mind that not just any ole' spark will do. It has to be a fat, healthy spark. Orange or reddish won't work, it won't jump the gap when actually installed in the engine and under compression.
An engine that won't start is real rough on all the components, solenoid, battery, starter. If it does finally start, it will then torture the alternator. Put the battery on a charger at let it cook at least overnight.
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Freshman User
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So the ground was bad between the block and firewall so I replaced it with no luck, then started searching for a ground for the frame and never found one. So I ran a ground from the frame to the intake, firewall to the intake, and another off the battery to the intake alone with the one going to the bloco. Still no luck really thought you were on to something haha. I'm going to run a direct ground for the coil?
really thought you were on to something haha. I'm going to run a direct ground for the coil?
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Unfortunately I did by a key switch but didn't come with the ignition like I thought it would. Spark looks great to me it's got one heck of a ark anyways. I'll grab one in the morning if oriellys has them in Stock. Does jumping the solenoid bypass the ignition?