1970 f100 w/390 starting hard
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Junior Member
Joined: Feb 2019
Posts: 2
1970 f100 w/390 starting hard
Daily driver, running fine starts easy. Take on fuel. Next day starts hard & stalls. Ok bad gas. Drain tank. Give it premium. Run down the hwy fine. Backing into drive it kills. Starts hard. Will idle but kills when put in gear. I start checking. Got plenty spark. Changed fuel filter. Plugs are dry & look ok but I changed em anyway. Fuel pump seems to be putting out enough. No obvious vac leaks. It’s a real simple arrangement. Cap & rotor clean. Has electronic conversion kit (not my doing I like points) but has plenty spark. Nice new Holley avenger carb. No troubles at all before I took on fuel. It’s still starting hard & kills when I drop it in gear. What have I missed? What else can I check?
Senior Member
Joined: Jun 2010
Posts: 16,529
You might try spraying some "Carb & Choke cleaner" into the air filter or air cleaner ( about a 1sec spray) and see if it starts.
If it does, good possibility problem with carb float level. If the needle and seat have a rubber type tip on the needle it may have swelled due to unleaded gas. If this is the case the engine will be starving for fuel due to low float level.
Sometimes a defective coil will do this also.
If it does, good possibility problem with carb float level. If the needle and seat have a rubber type tip on the needle it may have swelled due to unleaded gas. If this is the case the engine will be starving for fuel due to low float level.
Sometimes a defective coil will do this also.
Last edited by hanky; Feb 3, 2019 at 01:31 AM.
Thread Starter
|
Junior Member
Joined: Feb 2019
Posts: 2
You might try spraying some "Carb & Choke cleaner" into the air filter or air cleaner ( about a 1sec spray) and see if it starts.
If it does, good possibility problem with carb float level. If the needle and seat have a rubber type tip on the needle it may have swelled due to unleaded gas. If this is the case the engine will be starving for fuel due to low float level.
Sometimes a defective coil will do this also.
If it does, good possibility problem with carb float level. If the needle and seat have a rubber type tip on the needle it may have swelled due to unleaded gas. If this is the case the engine will be starving for fuel due to low float level.
Sometimes a defective coil will do this also.
i gave it a snort or carb cleaner & it fired but didn’t run
i checked the float level & it’s spot on according to the mfg sheet that came w/it
its squirting gas at least when I’m looking!
i went thru it again & im leaning towards fuel pump going bad
i disconnected the line to discharge into a can. It gives 3 or 4 good slugs & fills the can
i do it again get 2 slugs & some dribbles
again good slugs of fuel, 4th time nothing but dribbles
so process of elimination I’m going to replace the fuel pump
if that doesn’t get it I’m really stumped
i went thru the coil thing a few years ago chasing ignition troubles.
Must be a Ford thing-30yrs in LA heat in a belair on the same coil & it’s still going strong
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