1972 Ford Truck Jerking and Backfiring

1972 Ford truck 3/4 ton. Engine Size : 390

Question: I have a1972 ford truck changed the points, condenser, coil and cap. When I step on the gas it starts jerking. Backfires and dies but it will start up OK. Help.  Frustrated. When i step on the gas to go fast the above happens. Slow runs OK. When I hit the gas the problems start.

Answer: engine misfires on hard acceleration is usually caused by a problem in the ignition system. I would also suggest replacing the spark plugs and spark plug wires. Or you can spray down the spark plug wires with water while the engine is running to see if it starts to stumble. That would show a bad wire. Hard acceleration puts a heavy load on the ignition and that will cause it to break down. Hitting the gas and driving normal does not cause such a heavy load and will usually not make a bad spark plug or plug wire breakdown.

Being as old as your Ford truck is, you could also have an engine mechanical problem. You could have a worn camshaft lobe. This can cause backfiring through the intake manifold. You could have sticking valves in the cylinder head, a worn timing chain and/or tensioner, a broken valve spring or some other internal problems. But start with the basics and get the ignition system in perfect working order.


Leave your comments

Post comment as a guest

0

Comments (3)
   ---Subscribe To Your Comment   

  • Guest - eric

    whats been done so far--new battery, new plugs, new points & condensor, new ingition coil, new spark plug wiring, new distributor cap and rotor.

  • Guest - Bobby

    In reply to: Guest - eric

    Black smoke is usually caused by too much fuel- rich condition- flooded.

  • Guest - eric

    car starts but blows black smoke out exhaust

LATEST ARTICLES

How do Buy Here Pay Here car ...

How do Buy Here Pay Here car dealerships work? ‘Buy Here Pay Here’ is when a ...

How Things Work

How Do Hybrid Engines Work?

How Do Hybrid Engines Work? A hybrid engine is a cross between what we all ...

How Things Work

The Differences between Diesel and ...

The Differences between Diesel and Gasoline Engines Many 2019 trucks come in ...

How Things Work

Ford F-250 Water On Passenger Floor

2014 F-250 drips water on the passenger side floor. The drain on the firewall ...

Ford Auto Repair Questions and Answers

Impala Flashing Engine Light

I have a 2003/2004 impala i was driving it on the high way the other day and ...

Chevrolet Impala Car Repair Questions