What is this plug/wire for?

[K5_Fla]

See pic - a little plug with some wire that was hidden behind the distributer. My truck was a TBI / converted to carb… I’m thinking this little plug has something to do with the old TBI stuff.
Truck is standard 350ci

Everything on the truck works right…. Just courious.

 

[63chevyll]

that may have been one of the connectors for the IGN module, or the oil press sending unit

 

[K5_Fla]

but everything works.. oil sender and gauge are perfect.

 

[63chevyll]

the TBI engine used a different distibutor and connectors. I could see how everything works, the HEI you have now only needs one wire

 

[onetonbb74]

yes that wire plug looks like it went from the coil to the dizzy on the tbi setup

 

[K5_Fla]

cool... so it's just old TBI related junk....

 

[sweetk30]

tbi uses 2 oil pressure switches. on side of motor above oil filter for gauge .

on top of motor rear of block is now for the computer use.

basicly if the fuel pump relay fails then the pressure tells the computer to keep feeding the system. if i recall correctly.

if the plug is flat its for ignition. if its kind of round oil sesnor.

 

[4X4HIGH]

tbi uses 2 oil pressure switches. on side of motor above oil filter for gauge .

on top of motor rear of block is now for the computer use.

basicly if the fuel pump relay fails then the pressure tells the computer to keep feeding the system. if i recall correctly.

if the plug is flat its for ignition. if its kind of round oil sesnor.

Not all of them. My 89 uses a dual purpose oil pressure sender (3 wire) that operates the gauge AND the fail safe for the fuel pump relay back-up.

 

[79bonanza]

idk if my truck was just screwed up or what but when my 95 tbi lost oil pressure it didnt shut off until the rods were bending

 

[Big Ray]

MAP sensor....?

 

[djtejas]

tbi uses 2 oil pressure switches. on side of motor above oil filter for gauge .

on top of motor rear of block is now for the computer use.

basicly if the fuel pump relay fails then the pressure tells the computer to keep feeding the system. if i recall correctly.

if the plug is flat its for ignition. if its kind of round oil sesnor.

My 83 with carb had two oil pressure switches when it was stock...

 

[4X4HIGH]

idk if my truck was just screwed up or what but when my 95 tbi lost oil pressure it didnt shut off until the rods were bending

There would be no reason for the engine to stop unless you shut it off or it blew up and something stopped the engine from running.

You probably have to same misconception that alot of people have in thinking that the oil pressure switch shuts the engine off if under a predetermined PSI but that just isn't the case. The dual purpose oil pressure sender used on TBI trucks actually allows the fuel pump to continue working if the fuel pump relay goes bad AS LONG AS there is 5 psi of oil pressure.

 

[sweetk30]

MAP sensor....?

map plug most time green and or black plastic. and on right side of intake.

 

[79bonanza]

There would be no reason for the engine to stop unless you shut it off or it blew up and something stopped the engine from running.

You probably have to same misconception that alot of people have in thinking that the oil pressure switch shuts the engine off if under a predetermined PSI but that just isn't the case. The dual purpose oil pressure sender used on TBI trucks actually allows the fuel pump to continue working if the fuel pump relay goes bad AS LONG AS there is 5 psi of oil pressure.

ooooo ok that makes more sence now. i think i just read that wrong or something but it doesnt sound like to bad of an idea for car companies to do.
just run a kill switch into the oil pressure circuit to kill the engine if oil pressure gets to low to prevent alot of damage to the engine.