WOT bucking, surging and cutting out

[Bigal75]

1967 R/T auto, mild 440 with Carter carb. 3.23 gears.

At WOT the engine starts to buck and cut out, surge and almost stall out. Car has new plugs, wires ignition and coil. Runs great cruising around.

I'm thinking it's leaning out like the carb bowls are running dry. It does have a new generic mechanical fuel pump. Is it possible that either the pump rod is worn out or the sock in the tank is plugged? I've noticed a lot of crud in the fuel filter as well (which has been changed). I'm thinking the issue is fuel related.

Does it sound like a fuel issue?

 

[bigaadams]

IF you suspect a fuel pump..what have you done to check its volume output? What ignition system you running..?

 

[Bigal75]

New FBO ignition system and distributor, plugs are gapped at about 0.30. Timing is around 18 base and I think about 35 deg at wot.

I suspect fuel because the ignition is all new and the way it chokes itself under load. Lets say I take off from a stop at WOT it will burn through 1st gear then shift into second and a second or so in it will start to miss buck and die.

I haven't checked fuel pump volume output.

 

[HT413]

Mine did that about a year and a half ago, if I stayed in it it would die, if I got out of it it would recover and run fine from there. Sound about right? For me it was the fuel pump pushrod.

 

[khryslerkid]

If you keep getting dirt in your fuel filter, then you need to clean the whole system. A lot of dirt will get past the filter too. Remove the top from your carb and inspect.

 

[Bigal75]

HT413 - yep same thing. I let off it will idle and then as if the carb fills up again and I'm good to go for as long as I don't beat on it. khryslerkid I think you're right, a complete flush from tank to carb will be required.

 

[HT413]

HT413 - yep same thing. I let off it will idle and then as if the carb fills up again and I'm good to go for as long as I don't beat on it. khryslerkid I think you're right, a complete flush from tank to carb will be required.

Simple enough to check it. Pull the pump and remove the plug right below the pump. Only issue I had was the top of the rod was mushroomed so I had to take the whole front end of the motor apart and pull the cam. All for a $17.99 part.

 

[Bigal75]

What I'll do is flush everything out and install a new rod, I'll start with that

 

[Meep-Meep]

If you are sure the ignition is good then look at fuel delivery. My 66 Charger would drive fine around town but once on the freeway (just cruising at 70) it started acting up. It took me a minute but then it hit me. Fuel filter restriction on the primary carb (426 hemi car). I didn't even check the fuel flow as I was sure what the problem was. Pulled the filter and it felt like it had 10 lbs of rust particles in it. Put a new one on and problem solved.

 

[Bigal75]

Thanks!