Re: Diagnosis, please

Posted by HH56 On 2022/5/30 18:13:24

It could be a sign of impending vapor lock but usually that will be evident even in normal driving.

When you mash the pedal is the accelerator pump pushing out a good squirt when the pedal floors? Possibly the leather plunger seal has been forced out of position or if the leather was dry at some point a split could have occurred in the seal. There is a ball check valve in the pump bore to keep gas in the chamber from returning to the reservoir bowl when the pump is needed. Perhaps that check valve is not working. The vacuum timing advance mechanism could also not be working as designed.

If it has overdrive, the ign cutout portion my be working and causing the engine to stumble for longer than desired because something mechanical prevented a kickdown.