Oil pressure switch

Jcris

Chief Petty Officer
Joined
Apr 23, 2016
Messages
466
My 1996 4.3 LX (2 barrel, electric fuel pump) has been giving me problems on cold start. Everything on this motor looks original. I fired it up the other day after it had been sitting for a few months just to see how it would do. I pulled it outta the garage onto my driveway which puts the bow below the motor. After trying to start it I realized I couldn't hear the fuel pump running plus the buzzer for oil pressure seemed to be staying on for a long time. So i moved the boat onto the street in a more level position. Then it started with the usual coaxing of the throttle and i could hear the fuel pump running. There's maybe a 20 degree incline on my driveway which puts the bow below the motor. Would that incline affect the oil pressure switch to keep the motor from starting? The oil is fresh and at the correct level Does it make sense that the position of the boat would affect the oil pressure switch? I always start the boat the day before going out on the lake. If I'm going to have problems id much rather deal with it in the driveway.
Is it possible the switch may need to be removed and just cleaned? All the electrical connections look good. The sender for the gauge is teed into the same port for the oil pressure switch. What do you think?
thanks
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,722
Unsure of the 20 degree bow down issue, but would figure this shouldn't be an issue.

The oil pressure switch does not need to be closed for the fuel pump to run during cranking. There is a lead on the left outside of the starter solenoid (purple/yellow) which powers the fuel pump during cranking. Check to see if 12V is on the wire when cranking

4_3L elect diag.jpg
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Were you checking the oil level with the bow 20° down?
 
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