Oil pressure gauge question

I just replaced the oil pressure switch on my 94 Caprice, with the truck sending unit. (I don't remember the part number, just the AC Delco 0-60psi unit), and I also removed the resistor from the wiring harness. Hot idle I'm a little below the middle of the gauge. When driving it moves into the middle of the "good" range.

My question is, can I use the gauge markings to give a general PSI reading? As in, 60 psi would be gauge pegged, 30psi would be in the middle of the gauge, or is it still just an idiot gauge that moves a little now?

In any case I'm pleased as punch that the old girlie seems to be putting out good pressure with 200K on the motor.

Thanks!

I have one that reads from 8-30 psi with the engine running at different speeds. The other one reads 25-60 psi with the engine running at different speeds. They both have new Melling standard duty oil pumps less than 3 years ago. You should run a mechanical gauge in parallel to calibrate your gauge.

I believe you'd need a 9C1 gauge to read actual oil pressure, the civi unit is more of an "idiot gauge". Good news is it's easy to swap out just the gauge.

Fred Kiehl wrote:

You should run a mechanical gauge in parallel to calibrate your gauge.

Then once I know the range, remove and move the needle to where it reads properly? Or since I'm planning a few gauges, (a tach for one) running a mechanical oil pressure won't be too bad of an idea?

Crazy how far out the factory one is. I wonder if we got the rejects from the 9C1 clusters?

rauldelp wrote:

Then once I know the range, remove and move the needle to where it reads properly? Or since I'm planning a few gauges, (a tach for one) running a mechanical oil pressure won't be too bad of an idea?

Crazy how far out the factory one is. I wonder if we got the rejects from the 9C1 clusters?

Most of these issues were documented a long time ago. May as well start learning this stuff now rather than struggle with trial & error:

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Awesome resource, thanks! Good bedtime studies at least.

JaySS wrote:

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server not found?

I ran into that too. It looks like all the instructions are further down the page in order, but the anchor links don't work anymore. I used the find function to get what I needed

phantom 309 wrote:

server not found?

Thanks for pointing that out - for anyone that is unfamiliar with the documents, they were created nearly 20 years ago and the original author has long since moved on.

Unfortunately, the quick links still point to the original impala.homeip.net website.

So these copies require one to manually scroll through the document to get to the desired info.

- J