1993 Chevy P30 fuel pump help
Hi All - I have a 1994 Fleetwood Southwind on a 1993 P30 chassis. Got back from 4th of July weekend and was pulling into storage the next day and just as I placed it in Park and set parking brake the...
Forum Discussion
Sully2 wrote:
The normal engine mounted pump cant "suck" gasoline the distance it needs to go...hence the AUX pump inside the tank....to help with that problem an it runs as long as the engine is running
Yes it can. The engine-mounted mechanical fuel pump is perfectly capable of feeding the 454 on the longest of gas RVs. Mine does just fine on my Allegro M31. The trouble arises in a couple of areas that are moot for this discussion but I'll point them out anyway.
1) Vapor lock. Fuel boils in the line from the pump to the carb. The external fuel pump was installed from 1985 1/2 and up to help pressurize the system to avoid this problem.
2) Inoperative external fuel pump. The mechanical pump can't suck through a failed or inoperative fuel pump as well as if the path were unobstructed. It will work under most conditions, but will be prone to vapor lock more so than if the failed pump weren't in the path.
By 1993, however, an in-tank pump was used. It provides the higher pressure needed for the fuel injection and is not generally prone to the vapor lock issues suffered by the carb'd configuration.
