51 Special loosing oil pressure & stalling when I stop

**PFJN** · 08-09-2014, 06:59 PM

Hi,

I've bee looking through other posts here t see f I can try and figure out what might be wrong with my 51 Special. Overall, it starts and runs fine, but lately I've begun to notice that If I have been driving on a main road or highway(from 45 to 55 mph) and then come to a stop the oil pressure will begin to drop quickly and the engine will sometimes stall, typically with a mall backfire noise. I also notice that the electrical gauge may also drop to the “discharge”side as well.

While stopped, if theengine hasn’t stalled yet, if I switch the Dynaflow into neutral I notice the engine rev’s will come back up a bit and the oil pressure will return tonormal. In addition, on a couple occasions I’ve heard a whirring noise coming from the front of the car, and which could possibly be coming from the fuel pump.

Overall though, most of the problems really appear to occur(so far) when I am going from operating the car at higher speeds and come to a stop.

From some of the other posts that I’ve read I had begun to wonder if there may be an issue with vapor lock, or if it may be something else entirely, since the engine usually starts right backup with out any problem.

Also since the rev’s seem to comeback up and the engine runs smoother when I shift the car into neutral when I’m at a stop sign or stop light, it also kind of seems to me that the issue mayhave something to do with the load on the engine when at idle after having runat a higher rpm.

If anyone has any thoughts or suggestions, I’d appreciate it.

Thanks

Pat

**raycow** · 08-09-2014, 07:49 PM

All of the issues you mentioned except for the whirring noise are symptoms of a too-slow idle speed. If the engine has a throttle slow-closing device (also called a dashpot), it may be inoperative or adjusted incorrectly. It looks somewhat like a choke pull-off or vacuum advance unit and will be mounted on the carb or throttle linkage.

I have no clue at all about the noise.

Ray