1939 Olds (6) miss under load

[Guest Percy123]

Motor has miss under load, miss comes in at approx 50 mph? but ok at lower speed.

Done following;

new plugs, Rotor, Distributor cap, Coil, Carby. reset timing.

Any help please. Percy123:confused:

email kalb.b@bigpond.com<!-- google_ad_section_end -->

[rocketraider]

Percy, check the fuel filter if it has one. Also check resistance on the plug wires with an ohm meter, and clean and gap the points precisely if you can't find new ones.

[Tedd Thompson]

x2 on the check of resistance on the plug wires. I just had a new set of plug wires that had 3 inches of missing carbon in one of the wires, drove me nuts trying to figure that one out. No guarantee new parts are good. Tedd

[JFranklin]

The '39 should not use resistance spark plug wires.

[Guest Percy123]

Hi all, Found the Fuel Pump valves not working correctly. The fuel pump was reconditioned and had rubber valves, as soon as they were hot the valves didn't work as they should , so I replaced the valves with bakerlite seals in the valves and now working fine.

Again, thank you all for your suggestions and help.

Percy123<!-- google_ad_section_end -->

[rocketraider]

All wires have some resistance. I think you're referring to earlier cars did not use radio suppression plug wires.

As Tedd found out, a broken (electrically "open") wire can cause a difficult to diagnose problem.

Anyway- glad you found the problem.