Ok, I have never replaced my oil pressure sending unit before. It started acting up on me so I decided to change it. Is this the sending unit itself???

 

I got this for a replacment part. It just dont look right to me. Is it the correct one?

 

It depends on what one you're changing. You should have 2 back there. The big one in your 2nd picture is the correct sender for your gauge. The unit that your fuel pump circuit uses is a smaller switch with a 2 pronged snap-in plug. It looks similar to the first picture, but not quite the same.

 

Ok, so there are 2 different units My gauge is not working at all. Only after I drive 30 miles will it kick in and light up. I told the guy at pep boys that I needed a new sending unit for gauges, and that was the part he gave me. Now....I did a search in this forum and it really didnt help much. All I have to go on is that it is located directly behind the plenum and on the drivers side of the distributor. I took a pic of what I have back there and decided to ask for help. So.....im stuck.

 

i take it you have the digital gauges, right? i dont have these gauges but i know with the sending unit thing, just like with any GM small-block V8, look at the left rear side (on top) of the engine and you cant miss it. if that doesn't fix your problem then your problem is more that likely the sending unit. if you have to, grab someone out of your local parts store and show them in person what your dealing with so your can get the right part and get back in business! good luck

 

Looks like you maybe got a picture of the oil pressure switch (first pic). The thing in the second picture is a guage sending unit.
Not sure on the set up on the 88's for locations. On mine there is a tube with a large hex head that comes up from the back of the block on the driver side, another tube (hex shaped) screws into that one pointing back towards the firewall. The sending unit and pressure switch are both screwed into that piece.

 

Here is another pic of what I have. I tried to get the same angle you got Morley. The only things I see back there is a terminal connector and that sensor....but it really doesnt look like the one I have.

I also replaced the sensor above the oil filter. It didnt fix my problem. Hell, I dont even know what it does! But it was near oil so I replaced it

Any more hel would be greatly appreciated

 

opps forgot the pic

 

Ok, that wasn't the sender that you had in the second picture? In the frst picture under your hood there was a single blade connector, that should have been the sender. But like I said, I'm not familiar with the post '87 model's set up.

How many prongs were on the thing above your filter? If it was 2 then I'm thinking that was the oil pressure switch that goes to the fuel pump.

 

If your oil pressure switch, the one mounted down by the oil filter, has three wires on it then that also controls the guage.
My '89 has this type on it.

If it only has two wires on it then it is just the fuel pump switch, and the oil pressure sender is a little can ( the part in your pic) mounted behind the distributor on the intake.
My '86 has this type on it.

 

So if I take my distibutor cap off I should be able to see the sensor?

 

The last pic you posted, the sensor with the single orange wire, I believe that is the oil sender unit.

It's not necessary to take the cap off, but it may give you a little more room to work back there if you did.

 

ok here is a picture of the unit that I pointed out in my earlier post. Is this the factory sending unit???

 

Thats it! Take that to the auto parts store and get one just like it, I doubt the larger "can" type will fit.

 

Ok I took the part back. It was the only part that is available, the can-type that is. So I hooked it up and it started working again....well when I say it started working again I mean that now I at least get a light on my digital dash. The meter sits at 0 though. I just changed my oil yesterday so I know there is oil in there. WTF?????

 

My factory sending unit on my 88 GTA was the big cannon like in your picture above. The one that you have there looks more like an on/off switch for a dummy light, not a gauge sender.

 

well I am not sure how that gauge got in there. Must have been a previous owner or somthing. Anyway is there anything else that could be wrong that would keep my gauge reading a 0????

 

Other than a bad oil pump, dunno. What you had in there didn't look like an idiot light switch either, they usually have 2 prongs and look like the oil pressure switch. You could go to the auto store and see about getting a Sun mechanical oil guage and slave it in in place of the new sender, just to be sure you are getting oil pressure. If you have good pressure you'll need to look for a short or open on that one wire going to the sender.

 

I know this is kinda an older post but i didn't want to clutter up the web boards with too many
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So the oil pressure switch shuts off the feul pump if the pressure gets too low? Is that its job?
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If so, how does the engine start, since it won't have any oil pressure until its turned over a few times?
Sorry if this is stupid, but i don't know a whole lot yet.
aaron

 

The fuel pump circuit is kind of screwey. The oil pressure switch is wired in parallel with the fuel pump relay. As far as I know, if your fuel pump relay is working properly, the oil pressure switch is useless. If your fuel pump relay pukes, you can still start the car but it will take a ton of cranking because the fuel pump won't get power until you have oil pressure.

The oil pressure switch that's part of the fuel pump circuit has 2 pins though. On the 86- cars, it's a 2 prong plug, with both prongs looking just like the 1 prong shown on your pic. On the 87+ cars, it's still 2 pronged, but it accepts a weather-pack connector, and the 2 pins are very small, and recessed within the connector housing.