Bogging Down Issues
 

Hello Everyone!

I have a classic 65 F100 with a 72 Gran Torino 302. I am kind of stuck on an issues here. While at cruising speed at random times, I loose throttle. The engine bogs down. I can pump the gas/pedal to floor, but nothing happens. Ill pull to the side of the road and stop, then the engine picks back up again and runs fine. Its completely random. I just recently replaced carb (edelbrock 1405) I also adjusted fuel mix on carb, new fuel lines, distributor (flamethrower ignitor 2), (has older master blaster 2 ignition coil), new plugs, delphi mechanical fuel pump (had electric fuel pump), new battery. Installed new negative lead on battery and new ground lead to frame. . Idle RPM is set at 600. It also runs a little rough and when engaging into reverse, it wants to stall. While at idle and my headlights are on, the gauges and headlights flicker until I give more rpms. Tested battery/alt and the battery voltage is all over the place. Has original wiring harness under dash! Also wanted to add, that my gph is way, way down. A 1/4 tank only lasts about 30 miles!
Any thoughts for issues of bogging down, etc? Thank you for the replies and Happy Hollidays!

Just out of curiosity , was this problem present before changing fuel pump from electric to mechanical?

Sometimes the cam gets worn that activates the mechanical fuel pump and it was easier to install an electric pump.

No. I have thought about going back to the electric fuel pump, but didn't want to go back if it wasn't the issue. You would think that a mechanical pump would work well.
And with further research of the Gran Torino Stock Carb, it was a 2 barrel! Wonder if having a larger 4 barrel carb, the mechanical pump is unable to keep up!

Still Bogging Down
 

I installed a fuel pressure regulator. I turned it down from 6 psi to 4 psi. Bogging down issues still occur at or around 50 mph. On another note. I recently rebuilt top end. There is a weird howling sound, almost like an air leak, not sure. Would an air leak at intake manifold be a cause for bogging?

I installed a fuel pressure regulator. I turned it down from 6 psi to 4 psi. Bogging down issues still occur at or around 50 mph. On another note. I recently rebuilt top end. There is a weird howling sound, almost like an air leak, not sure. Would an air leak at intake manifold be a cause for bogging?

Could there be some kind of air restriction blocking the air from coming into the intake?

No. The air cleaner element/base and filter are brand new as well

The best way to confirm there is not a restricted air intake problem is to try driving it with no filter assy attached. It only takes one trip to make sure that is not the problem.

Its not it. I am starting to think my delphi mechanical fuel pump is bad. It all started going south after I rebuilt top end, installed new carb and switched to mechanical fuel pump. I have found that the carb is not the issue. Swapped with another carb, but bog still exists. I really need to do a compression test. I have no idea if the pistons are bad or rings, etc. There was a lot of coolant on top of 3 pistons when I removed heads for rebuild. I also checked for vac leaks using carb cleaner, but no luck.

Not much can go wrong with a mechanical fuel pump if it is not leaking fuel out its weep hole or into the crankcase. I wouldn't rule out a worn cam lobe for the mechanical fuel pump.