460 problem
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Freshman User
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460 problem
83 F350 4X4 with 460, just fixed steering issues, now having problem with 460. Driving on freeway, it farted through carb, stalled, died on side of road. I have a Holley 750 on it.
Any ideas?
Any ideas?
FTE Legend
Joined: Jul 2010
Posts: 32,875
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From: Northeast, OK
A backfire through the carb on a Holley will blow the power valve unless it is one of the newer ones with a check valve. If so, the engine is going to be very rich and you'll have to make sure the choke is fully open.
As for ideas, check to see if you have spark. If so, check to see that you have fuel in the carb by pulling the air cleaner, looking down the throat, and briskly opening the throttle. If you don't see two jets of fuel then the carb doesn't have gas.
As for ideas, check to see if you have spark. If so, check to see that you have fuel in the carb by pulling the air cleaner, looking down the throat, and briskly opening the throttle. If you don't see two jets of fuel then the carb doesn't have gas.
FTE Legend
Joined: Nov 2015
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From: Angier, NC
What you try and start it what does it do and sound like?
How many miles on the motor?
Get the crank set to TDC, pop the dist. cap and see if the rotor is pointing to plug wire #1 or 180* off. If 180* off turn the crank till it is at TDC.
My thinking is the timing chain went south and you are going north.
That is if what Gary posted does not pan out.
Dave ----
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Joined: Apr 2017
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From: Northern Utah
Had 120,000 miles on mine before it sucked the umbrella seals into the oil pump and corkscrewed the distributor drive shaft breaking three teeth of the distributor. stopped the engine rather quickly. Make sure rotor turns when you crank the engine-
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Freshman User
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What Gary posted is all good but I think it is something deeper than that.
What you try and start it what does it do and sound like?
How many miles on the motor?
Get the crank set to TDC, pop the dist. cap and see if the rotor is pointing to plug wire #1 or 180* off. If 180* off turn the crank till it is at TDC.
My thinking is the timing chain went south and you are going north.
That is if what Gary posted does not pan out.
Dave ----
What you try and start it what does it do and sound like?
How many miles on the motor?
Get the crank set to TDC, pop the dist. cap and see if the rotor is pointing to plug wire #1 or 180* off. If 180* off turn the crank till it is at TDC.
My thinking is the timing chain went south and you are going north.
That is if what Gary posted does not pan out.
Dave ----
I bought the truck from some kids selling it to help out their dad, and i suspect somewhere along the line they pulled out original 460 4x4 460 and replaced with a 2wd 460 because it has both front and rear dipsticks. Valves say 1975 on them, so its a mystery as to how many miles are on it, or where it came from.
pedant
Joined: Jan 2008
Posts: 23,576
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From: EXTREME southwest CT
I agree 100% with this.
People on here say the module gives signs before it goes.
But mine always just backfires once and craps out.
People on here say the module gives signs before it goes.
But mine always just backfires once and craps out.
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pedant
Joined: Jan 2008
Posts: 23,576
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From: EXTREME southwest CT
Others are suggesting the timing chain, which would stop the distributor turning.
still a no spark situation.
Easy enough to remove the cap and see if the rotor is turning.
Pretty sure it was 1991 when Holley started putting powervalve to blowout protection in their carbs.
still a no spark situation.
Easy enough to remove the cap and see if the rotor is turning.
Pretty sure it was 1991 when Holley started putting powervalve to blowout protection in their carbs.
Moderator
Joined: Jan 2001
Posts: 56,965
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From: Virginia
I have never seen a timing chain totally break in two. They usually get very loose and then jump some sprocket teeth. So then the engine stops. After that you will have spark, the engine might hit once in awhile, but it will never run. And a key symptom to the chain jumping some teeth is when you are cranking it trying to get it to start, the cranking speed is very erratic.
You said now it will actually try and run for a few seconds. I don't think that is going to be the timing chain, try the ignition module like the other guys suggested.
You said now it will actually try and run for a few seconds. I don't think that is going to be the timing chain, try the ignition module like the other guys suggested.
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Freshman User
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I put a new ignition module in about 6 months ago for unrelated issues, however it would be my luck it would fail. Cheaper to try and put in a new one to start eliminating things. Also has new distributor and coil.
Will report results.
Will report results.
FTE Legend
Joined: Nov 2015
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From: Angier, NC
All good information given so do some checking before throwing parts at it.
Then again a spare box never hurts to have on hand.
When I have had boxes go it never "farted" (would that be a sneeze if it came out the carb?) it just died like turning off the key.
I had 1 chain jump (chevy 350) and when cranking it turned over like no spark plugs were in it.
But I guess it could jump a few teeth and make it fart/sneeze.
Time to do some digging, start easy with spark and if dist. is turning and pointing to #1 and go from there.
Dave ----
Then again a spare box never hurts to have on hand.
When I have had boxes go it never "farted" (would that be a sneeze if it came out the carb?) it just died like turning off the key.
I had 1 chain jump (chevy 350) and when cranking it turned over like no spark plugs were in it.
But I guess it could jump a few teeth and make it fart/sneeze.
Time to do some digging, start easy with spark and if dist. is turning and pointing to #1 and go from there.
Dave ----
Thread Starter
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Freshman User
Joined: Aug 2016
Posts: 39
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All good information given so do some checking before throwing parts at it.
Then again a spare box never hurts to have on hand.
When I have had boxes go it never "farted" (would that be a sneeze if it came out the carb?) it just died like turning off the key.
I had 1 chain jump (chevy 350) and when cranking it turned over like no spark plugs were in it.
But I guess it could jump a few teeth and make it fart/sneeze.
Time to do some digging, start easy with spark and if dist. is turning and pointing to #1 and go from there.
Dave ----
Then again a spare box never hurts to have on hand.
When I have had boxes go it never "farted" (would that be a sneeze if it came out the carb?) it just died like turning off the key.
I had 1 chain jump (chevy 350) and when cranking it turned over like no spark plugs were in it.
But I guess it could jump a few teeth and make it fart/sneeze.
Time to do some digging, start easy with spark and if dist. is turning and pointing to #1 and go from there.
Dave ----
when i put new holley on it when i got it home, it did a little through the carb again.I am still leaning towards the timing chain jumping a tooth; i had a mustang do that years ago and experienced similar symptoms.
I sure love this truck because it is a Marti report verified one of one built, but man am I getting frustrated with it!
pedant
Joined: Jan 2008
Posts: 23,576
Likes: 38
From: EXTREME southwest CT
This is *way* different than how I read your first post (and far more in keeping with a slipped chain)
Use the double roller set from an '88 and up efi truck.
These have steel gears instead of nylon and are not retarded for emissions.
Be prepared to replace the crankshaft counter weight or install a repair sleeve so the front main seal doesn't start leaking immediately because the surface is scored.
Use the double roller set from an '88 and up efi truck.
These have steel gears instead of nylon and are not retarded for emissions.
Be prepared to replace the crankshaft counter weight or install a repair sleeve so the front main seal doesn't start leaking immediately because the surface is scored.
it backfired through carb a few times, then exhaust, and then began to quickly stall. My luck I was on freeway in the middle lane and only about 2 miles from home when i put new holley on it when i got it home, it did a little through the carb again.
I am still leaning towards the timing chain jumping a tooth; i had a mustang do that years ago and experienced similar symptoms.
when i put new holley on it when i got it home, it did a little through the carb again.I am still leaning towards the timing chain jumping a tooth; i had a mustang do that years ago and experienced similar symptoms.
Posting Guru
Joined: Apr 2011
Posts: 1,636
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From: Orlando area
Anything can be broken. These pics are from the 460 forum.
This chain broke when the end of the fuel pump arm broke off and got caught between timing gear and chain. Engine builders/racers on the forum said it is even more unusual for a fuel pump arm to break.