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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Nthefamily on July 17, 2019, 03:10:22 PM
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Team,
I have a '85 K10 that originally had a 305 with a Q-Jet carb & electric choke but has since been swapped over to a BBC with an Edelbrock carb & electric choke. This is not a daily driver, but something to putt around town in on non rainy days in summer with a/c on and winter with heat on ;D
When I changed to the BBC, I put a new oil pressure light switch (small switch w/2 wires) AND an oil pressure gauge switch (large switch w/1 wire) since it originally had both. They are both mounted to a fitting I installed on the back of the block. Last week when I cranked it up, I noticed a little smoke coming up from engine bay on driver side and began to investigate. I saw a few drops of oil on driver side dripping onto the hedder so I proceeded to shut'er down. After further investigation, I found that oil was either coming from the brass fitting that the oil pressure light switch is mounted to or the switch itself.
I thought (if my old memory serves me right) I had read somewhere back sometime ago that the oil pressure light switch worked the choke light on the original engine with electric choke.
Question - Do I need the oil pressure light switch since I've swapped engines or can I delete it out of my plumbing? I know I need the pressure gauge switch since I still have the factory oil gauge which works.
Thanks for any insight.
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I would retain it to control power to the electric choke. See GM electric choke operation for Q-jet carbs (http://forum.73-87chevytrucks.com/smforum/index.php?topic=36868.msg309686#msg309686) for details of operation.
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Good read and thanks, will do.
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Okay, I'm retaining the oil pressure light switch but can anyone tell me where on a BBC each one of the oil pressure switches are supposed to be mounted?
Right now, I have both mounted to the port just above the oil filter using a "T" fitting.
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There are only two locations used for oil pressure transducers. One is behind the intake manifold adjacent to the distributor. The other is immediately above and outboard of the oil filter recess located at the left rear lower corner of the block. The dash gauge oil pressure sender (OPS) uses a single tan wire terminating in a flexible black rubber cup connector that snaps over the end of the sender. The choke light OPS uses a two-terminal flexible black rubber cup connector with three wires attached (pink, dark blue, and light blue). Look for the original wire connectors and install the respective senders accordingly.