318 sputters under load
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318 sputters under load
I have 2 chrysler 318's the port has started to sputter under a load. popping and hesitation at 6 knots it runs well but as I add throtle it starts to pop and sputter stall and backfire at the carb any ideas as to a fix I am using m.s.d. so I am getting a hot spark
1973 f32 twin 318's raw water cooled
- Commissionpoint
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Re: 318 sputters under load
whats your total advance, and how is the condition of your fuel/water seperators?
1978 F-32 "Eclipse"
Merc 305 SBC's
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Merc 305 SBC's
1.52:1 Borg Warners
1983 Correct Craft
Commander 351 Ford (PCM)
1:1 Borg Warner
There are 350 different varieties of shark, not counting loan or pool.
- prowlersfish
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Re: 318 sputters under load
Look the Cap and check your wires . what type of "m.s.d" unit are you using ? That also could be a proplem . You could also have a fuel issue . check your filters like CP said . but you could have trash in the carb. As you see there is not just one thing that can cause a proplem .
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77/78 TROJAN F36 Conv.
6BTA Cummins diesels
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Re: 318 sputters under load
I agree, the MSD unit could be your problem. I had an MSD unit on my hot rod and it failed, the symptoms were like yours only intermittent......
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1998 Kawasaki ZXi 1100
1972 Chevy Fleetside Shortbed hotrod.......450hp
10.5 Newport Inflatable w/15hp Rude
Re: 318 sputters under load
I've had that problem due to a partially blocked anti siphon valve at the top of the fuel tank.
Paul
"Cruise Control" 1978 F-26HT
"No Control" 2012 9' Grand RIB
"Cruise Control" 1978 F-26HT
"No Control" 2012 9' Grand RIB
Re: 318 sputters under load
what are the initial setting for the carb ??? I have 3 screws 2 are the idle but what is the big one between them and what is the setting????
1973 f32 twin 318's raw water cooled
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Re: 318 sputters under load
I assume you have Cart AFBs on both engines. Mine only have two screws which are the idle adjustment screws, high speed jets are fixed. If one engine is fine I would start swapping some parts from one to the other. when it cures you will have the culprit assuming the other engine is running well.
Larry Eddington
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1984 F-36 Tri Cabin "The Phoenix II"
1978 F-28 "The Phoenix"
Fish Master 2350 Bay Boat
9.5' Dink
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Re: 318 sputters under load
Can you switch the fuel supply? If you have a fuel manifold put the bad engine on the good engines tank and see if the problem goes away. That will answer the fuel supply concern..... Then you are down to carb and ignition problems and can work through those.
I had a partially blocked siphon valve at top of tank that prevented enough fuel flow at anything above low speed travel which showed same symptoms.... Mechanic had run to distributor problems first and it was not there.
I had a partially blocked siphon valve at top of tank that prevented enough fuel flow at anything above low speed travel which showed same symptoms.... Mechanic had run to distributor problems first and it was not there.
Michael
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1978 F32 Sedan twin 318 Chry SOLD
Safe Cove Marina, Port Charlotte, FL
Rum is the reason Pirate's have never ruled the world
Done Dreamin'
1987 President 43' Twin Lehman 225SP Turbo
Highfield 310 Ally 15 HP Yamaha 2cycle
1978 F32 Sedan twin 318 Chry SOLD
Safe Cove Marina, Port Charlotte, FL
- P-Dogg
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Re: 318 sputters under load
Two transposed spark plug wires would cause this problem. You didn't say, but let me guess: It spools-up fine in neutral, but not in gear?
Here's the deal: At low power output, the other cylinders are able to compensate for the loss of power from the "missing" cylinders. When you accelerate under load, the vacuum advance causes the spark timing to now occur when the intake valve on one of the screwed-up cylinders is still open, causing the backfire through the carb. As alluded to earlier, check to make sure that the plug wires are firmly on the plugs, and that they are in the correct order at both ends. And be sure to let us know what the solution was.
Here's the deal: At low power output, the other cylinders are able to compensate for the loss of power from the "missing" cylinders. When you accelerate under load, the vacuum advance causes the spark timing to now occur when the intake valve on one of the screwed-up cylinders is still open, causing the backfire through the carb. As alluded to earlier, check to make sure that the plug wires are firmly on the plugs, and that they are in the correct order at both ends. And be sure to let us know what the solution was.
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Re: 318 sputters under load
When was the last time you changed the plugs. If its been awhile, pull one out to see what it looks like.
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Re: 318 sputters under load
Any updated info or results to the problem? Has it been resolved? Im also experiencing the same issue with my 1980 F32 with new 360's. Carbs are rebuilt. Anti syphons are good. Checked timing. Went through the suspected port carburator three times and even swapped the starboard carb to the port engine and it ran good.