Oil pressure gage help!

[87Hi-v15HND]

Anyone know what this is?? Can’t figure out what it plugs into...

 

[87Hi-v15HND]

Anyone know what this is?? Can’t figure out what it plugs into...

Idk what happened. Photo didn’t upload but here it is

You must be registered for see images attach

 

[87Hi-v15HND]

Idk what happened. Photo didn’t upload but here it is

You must be registered for see images attach

Maybe the ignition timing connector? Idk I can’t find anything else about it...

 

[1987 GMC Jimmy]

I believe that wire is a diagnostic lead for applying 12V to the pump, which you can also do at the ALDL. Something’s wrong there with the oil sender. It looks like it’s threaded into a coolant drain plug, which is where knock sensors and block heaters go, but that’s it. It should be directly above the filter, not near it. Here’s a picture of the oil safety switch in the correct location. It’s not the sender, but you’ll get the idea. I’d make sure your knock sensor is on the other side just to be sure. Placing that sender in the correct hole should fix you up.

You must be registered for see images attach

 

[hatzie]

Idk what happened. Photo didn’t upload but here it is

You must be registered for see images attach

Fuel pump test terminal off the Metripack 280/630 fuel pump relay. You can energize the fuel pump when the relay is not switching by applying 12v to that connection.

This schematic snippet is from my dual tank Theory Of Operation writeup on the 47-current chevy truck boards 73-87 sub-forum. If you only have one tank the "NL2 Switch" is the fuel pump...

You must be registered for see images attach

This is the sending unit on the side of the block. I couldn’t get a picture of the one behind the distributor but like I said it’s a brass fitting and the sensor threads into it and there is a plug that plugs into it. Started the truck and it is pegged all the way to the right passed 60psi.

You must be registered for see images attach

That looks like you have your oil pressure sender screwed into the block coolant drain hole along the oil pan rail where the ESC knock sensor or a 1/8" NPT pipe plug goes.

I believe that wire is a diagnostic lead for applying 12V to the pump, which you can also do at the ALDL. Something’s wrong there with the oil sender. It looks like it’s threaded into a coolant drain plug, which is where knock sensors and block heaters go, but that’s it. It should be directly above the filter, not near it. Here’s a picture of the oil safety switch in the correct location. It’s not the sender, but you’ll get the idea. I’d make sure your knock sensor is on the other side just to be sure. Placing that sender in the correct hole should fix you up.

You must be registered for see images attach

That's the oil pressure switch for the fuel pump power circuit.

 

[87Hi-v15HND]

Fuel pump test terminal off the Metripack 280/630 fuel pump relay. You can energize the fuel pump when the relay is not switching by applying 12v to that connection.

This schematic snippet is from my dual tank Theory Of Operation writeup on the 47-current chevy truck boards 73-87 sub-forum. If you only have one tank the "NL2 Switch" is the fuel pump...

You must be registered for see images attach

That looks like you have your oil pressure sender screwed into the block coolant drain hole along the oil pan rail where the ESC knock sensor or a 1/8" NPT pipe plug goes.




That's the oil pressure switch for the fuel pump power circuit.

Yea so the, “oil pressure switch for the fuel pump circuit” on my truck looks similar to that but is screwed in just behind the distributor and is “L” shaped.

The one that is supposed to go to my oil pressure gage, (the one on the side of the block driver side) is that in the wrong spot? It will not fit above my oil filter because the “can” is too wide. I can only get it on about two threads before it bottoms out on the edges of the block.

 

[1987 GMC Jimmy]

I just posted that switch as an example of the location. That oil sender is definitely in the wrong the spot, though. Only knock sensors and block heaters go in there. I don’t know what kind of space there is to do it, but you may have to get some kind of tee or tree shaped splitter for the port behind the distributor to run both things in the same spot. Where is the clearance issue by the oil filter? My sender is there, and it’s a very tight fit, but somehow it works.

 

[87Hi-v15HND]

I just posted that switch as an example of the location. That oil sender is definitely in the wrong the spot, though. Only knock sensors and block heaters go in there. I don’t know what kind of space there is to do it, but you may have to get some kind of tee or tree shaped splitter for the port behind the distributor to run both things in the same spot. Where is the clearance issue by the oil filter? My sender is there, and it’s a very tight fit, but somehow it works.

The clearance issue seems to be that the oil sender is too wide and I can only get it on like two threads before it bottoms out. I’ll go outside and see if I can get a picture and point to where it’s having the issues

 

[crpntr78]

On my '86 305, both the oil pressure sending unit and the oil pressure safety switch are behind the engine by the distributor.

 

[crpntr78]

Chegny has a very good picture he posted of the fitting used back there to accommodate both.

 

[87Hi-v15HND]

I just posted that switch as an example of the location. That oil sender is definitely in the wrong the spot, though. Only knock sensors and block heaters go in there. I don’t know what kind of space there is to do it, but you may have to get some kind of tee or tree shaped splitter for the port behind the distributor to run both things in the same spot. Where is the clearance issue by the oil filter? My sender is there, and it’s a very tight fit, but somehow it works.

Where both of my fingers are is where the sender bottoms out. Maybe have the wrong sender? Do you have a photo of yours?

You must be registered for see images attach

 

[Jerry phillion]

I just went thru the same situation. My 87 350 is a tbi . I
Assume yours is tbi also. Anyway, threaded hole just above oil filter is where oil sender for gage goes. Get a 2"or 3" long black
1/4" pipe nipple and a 1/4" 90 degree elbow. Screw these into block , the then screw sensor into elbow. You should have a tan
Single wire hanging down right there. Plug that onto end of
Sensor. Remove sensor from where you had it and put pipe plug in block.

 

[87Hi-v15HND]

I just went thru the same situation. My 87 350 is a tbi . I
Assume yours is tbi also. Anyway, threaded hole just above oil filter is where oil sender for gage goes. Get a 2"or 3" long black
1/4" pipe nipple and a 1/4" 90 degree elbow. Screw these into block , the then screw sensor into elbow. You should have a tan
Single wire hanging down right there. Plug that onto end of
Sensor. Remove sensor from where you had it and put pipe plug in block.

Ok that sounds good only problem is my wire is actually green. I spliced it to make it longer so it wasn’t laying on the headers

 

[87Hi-v15HND]

What if I installed an after market oil pressure gage? Copper tubing to the port above the oil filter? And just do away with the sending unit?

 

[75gmck25]

I have the stock mechanical oil pressure gauge on my '75 350, and the copper line is connected to the port behind the distributor. AFAIK, when they switched to an electric gauge in about '77 they screwed the electric oil pressure sending unit into the same place behind the distributor.

I guess that in the TBI era they starting using the location near the oil filter. However, the port behind the distributor should also work fine.

Bruce