Okay, so I may be putting this in the wrong section but I have an 85 305 t/a with the qjet 4bbl. Earlier this morning the car ran phenomenally when i went to get gas. About an hour ago i hopped in her to go to the store and revved her up to about 2500rpm and she just died. but every other time as she was about to die she would come back and diesel. So i decided to take her around the block, and the same thing happened, got up in second gear and she died. over and over again and occasionally accompanied by a loud backfire. Any and i mean any suggestions on where to start looking would be much appreciated.

Thanks
Austin

 

Retarded ignition timing can cause this because when the initial is retarded you must open the throttle more to maintain a certain idle sped. Opening the throttle blades can cause run on. Advancing your inital will allow you to close the throttle more at idle and reduce the chances of run on. Also, a cam being advanced can cause extremely high cylinder pressures because the intake valves will close sooner. High cylinder pressures can also cause run on.

 

UPDATE:

Just replaced the alternator (V regulator was completely fried) and she seems to be running cherry.. No loss of power and no stalling at higher rpms... Anyone hear of this happen?

 

Um..... no.

Even if the alternator didn't have a belt on it at all the battery would run the ignition and other electrical stuff from some time until it discharged to the point it wouldn't run any more.

Something else is probably going on. Hopefully it won't return, but don't be too surprised if it does. Not that you shuld be freaking out, but don't schedule any cross-country trips in the car just yet.

 

Carburetors do not like to be revved under load when cold. Choke could have been stuck on. Carburetors are affected by the weather bad.

 

Thats the thing though is that the alternator was hooked up and working (ish) and was in overcharge mode due to a failed regulator. So would that abundance of voltage to the battery (18+V) cause the car's computer to wig out and shut down until all is set back to normal (thus why it would come back to life after deiseling)? And the car was warmed up (just above 220*) so the choke wouldnt have anything really do do with it if its already wide open.

Just making sure all the facts are out there

Austin

 

If the alternator isn't working the choke heater relay won't close and warm up the choke. Engine temp isn't enough to open the choke.

That would explain the high idle. But, it doesn't explain the shutting off.