ok i am trying to install an aftermarket oil pressure gauage but i cant figure out where the sending unit is. where do i plug in the gauge, i read my haynes book and it didnt say anywhere in there.

 

I beleive the oil pressure sensor is right next to the oil filter.

 

so i just unscrew that, and screw in the new one?

 

Yup. old one out, new one in....It might take some SERIOUS force to get the old one out...When I still had the 2.8 in my camaro I ended up taking it to a buddies shop and having him do. that thing wouldn't budge for me.

 

it may depend on the year of your 2.8. i know with the v8's they switched to having it near the filter in 89, but before that it was up by the distributor on v8s and down low on the block on v6's. thats where the one on my 86 is.

on this picture look just below the number 2 spark plug wire, that gold/brown thing is the OPSU.


here is a better picture. funny thing, this is the same engine as the picture above, much has changed eh?

 

so basically i take that whole big gold tube off the block, and just bolt in the new littel tiny sending unit? or does the new sening unit attach into the big gold tube thing?
i have one of those gold tubes on mine by the way.

 

the gold tube (i always thought it looked like a bell) IS the oil pressure sending unit. remove it and replace with the new, smaller one.

 

 

Xophertony, that is very clean engine bay, VERY nice.

I had a oil pressure sending unit near my fuel filter (busted it off installing headers) I threw it out before looking at it. When i ordered a new one i noticed there were 2 kinds, 1 plug and 2 plug. Anyone know which plug i use.

 

Yes, I know it has been eleven years since anyone posted to this thread.

While I was poking around the oil pump on my 1988 2.8 today, I noticed two senders/sensors that looked like they are attached to the oil pump.

Am I correct that the big silvery-colored unit that is higher is the oil-pressure sender?

What is the lower unit with two wires?

This pic from one of the thumbnail images above. Identical to my car. Viewing both units from beneath the car.

 

The silver one is for the dash gauge. Usually there's a oil pressure switch that is tied into the fuel pump circuit also. On later cars they used a sensor with the switch built in.

 

Aha!

Thank you for the clarification. So, there ARE two separate oil pressure sending units, each with their own dedicated wiring harness connectors.

I ran across this in my reading last night:
https://www.thirdgen.org/forums/tech...relay-ecm.html

 

IIRC, code 54 is ECM failure.

So the second OIL PRESSURE switch takes over powering the FUEL PUMP if the ECM craps out?

 

Just looked up my the code chart.

Code 54 is low voltage in fuel pump circuit. So, does a Code 54 cause the redundant oil pressure circuit to send power to the fuel pump?

 

Not sure who you are addressing on this dead thread. There is a splice between the ops and relay on the pump feed wire. This splice contains a wire that goes back to the ecm that is a monitor signal.

 

What I'm really getting at is this:

I have a running car with a 1988 V6. The long block has two sending units coming off the oil pump.
I have a spare motor from a 1992 V6 that has one sending unit coming off the oil pump.
I have learned from this thread that the single 1992 sending unit is capable of doing the work that was done by the two sending units in 1988.

I'd like to "refresh" the 1992 long-block, and have it ready-to-install, when I get around to pulling the tired 1988 motor out of my running car. The plan is that I will install all the intake and exhaust system from the 1988 car on the 1992 long-block.

Before I get started on the 1992 motor, I want to examine all the accessories on the 1988 car, and I want to be sure those accessories will bolt-onto the refreshed 1992 long-block. I can't afford to get caught in the trap of discovering extremely-complex incompatibilty issues once the 1988 motor is pulled, and lying in the driveway.

As it stands now, I have this discrepancy in the connectors/sensors/senders to the oil pump. So, I want to know if the discrepancy is a deal-breaker due to the 1992 sending unit controlling critical systems in a manner wholly different than the manner in which the 1988 wiring harness is set up.

That's why I'm trying to figure out what the oil pump sensors/senders control.

Maybe its just as straighforward as installing the 1988 oil pump (and its two sensors/senders) on the 1992 long block.
Although I hadn't really anticipated having to swap the oil pump between the two motors.

Any information in regard to making the 1988 accessories/senders/sensors match up with the 1992 long-block would be greatly appreciated.

 

The two senders one is for a gauge or idiot light. The other is for relay backup . You can look at RockAuto.com under a 3.1l 1992 application for one sender that does both and are two listing one for a idiot light and one for a gauge. The center pin is for the gauge or light. The outer two are the pump wire and power polarity doesn’t matter. Getting a pigtail from a tbi truck or v8 fbody or acdelco makes a pigtail.
https://www.tpiparts.net/inc/sdetail/3995
A few links to part numbers on this thread
https://www.thirdgen.org/forums/v6/7...uge-dummy.html

 

Very helpful information. Thank you.

My 3.1 motor in waiting has single sender.
Seeing this got me kind of worked-up over the prospect of the 1988 wiring harness not being compatible with the 1992 long block.

At some point, I think I understand that the ECM is "seeing" input from the oil pressure sender.
(Code 54 (low fuel pump voltage) tells the ECM to look to the oil pump - of all things - to provide better voltage to keep the fuel pump running?)

Can I "combine" the three wires, going into the oil pressure senders on the 1988, in an effective way that will allow me to "upgrade" to the 1992-style sender on the 1992 long block?

I really would prefer to not have to swap the 1988 oil pump onto the 1992 long block just to keep the ECM happy.

FWIW, in a cardboard box out in the shed, I also have the wiring harness from the 1992 Firebird, and which probably has the pigtail for the 1992 sending unit.

Am I correct that it truly is as simple as this?:

• The 1988 has three wires going into the oil pump.
• The 1992 has three wires going into the oil pump.
• So, all I have to do is connect the three 1988 wires (currently going into two senders) from the 1988 to the single sender-unit on the 1992 long-block?

 

Can I "combine" the three wires, going into the oil pressure senders on the 1988, in an effective way that will allow me to "upgrade" to the 1992-style sender on the 1992 long block? Yes get a sender and pigtail for a 92 with gauge or light whatever you have.

 

Of if there is only one port on the 3.1l use a t and use the two senders off the 2.8l

 

Good to know the different configuration on the senders won’t be a deal breaker.