91 Deville -- Possible Wrong Gas? Bad Fuel Pump?

JDSMITH

MEMBER
1991 CADILLAC DEVILLE

91 Cad. Deville- Approx 120,000 miles- 4.6 L
"She" said she was running on fumes getting to the gas station. Accidentally pumped approx 2 gallons 'regular unleaded' instead of the usual 'premium' as she always has. Managed to drive it about a mile to her house, but was running rough. Now with 2 gallons of regular unleaded gas, it won't start at all. A slight "putt" every few seconds-- sounds like a timing "putt". Error code shows E52. That was from some guy changing the battery while it was setting. Does that code HAVE to be cleared before it will start? Could the pump have gone bad that quickly if a LITTLE air got into the fuel line? Is the pump that sensitive?

OH.I sprayed starting fluid into the breather. Nothing. Shouldn't it have fired up?

2 Replies

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

The regular unleaded is not the issue here, running so low on fuel is the issue. When you get down to the "dregs" you start to pick up all the sediment and muck that has settled in the "well" of the fuel tank. Fuel pumps are quite fragile things, and with the muck that has been forced through the pump it may be on the verge of seizing, also the fuel filter, which I suspect has not been changed for some time, will also be nearly blocked, EFI engines require extremely clean fuel systems, so have the pump checked change the filters and keep at least 1/4 tank full all the time.

Mark (mhpautos)