Expert: Robert Summers - 9/26/2009

Question
1994, Chevy P30, 7.4L.  Displays code 54 - Fuel Pump Circuit (Low Voltage).

Will not start (cranks all day) unless I spray starting fluid into throttle body.  Then starts right up and runs fine.

Replaced fuel pump.  Still getting code and won't start normally.

Read about a fuel pump relay, but cannot find it, not am I sure if this van even has one.  Does it use a relay?  Checked Auto zone and they don't list the relay?

Does the ECU perform this function on this model?  Cannot find any data.

Thanks for the help..

Answer
Hi Ken,  Yes there should be a fuel pump relay, and according to my mitchell on demand it is located on the passanger side of the rad shroud. there is also an oil pressure/fuel switch. that is why once you get it started it will stay going. the oil pressure switch will turn on the fuel pump once it reaches a pre set oil pressure... if you changed the pump then it is likely that you need to change the relay... hope this helps