I hooked up my Autometer electric oil pressure gauge and sender today but it's reading 100 PSI at idle and moves higher when I rev it up a bit. The max reading is 100 PSI and from what I understand it should be quite a bit lower at idle. Any ideas why?

This is how the install was done:

I drained my oil and removed my oil filter. I then removed the factory oil pressure sender. I installed a brass barbed fitting with pipe thread sealant. I then clamped a length of 1/4" fuel line about 5" long to a brass T fitting that I connected the factory sender and the Autometer sender to. I sealed all those connections too. I figured that I'd need to ground the senders since they were not grounded to the block because I had used fuel line. I grounded the T fitting to a bolt in the engine compartment and checked the fitting with a multitester to make sure it was grounded... it was. I then ran the signal line from the Autometer sender to the "S" terminal on the gauge in the passenger compartment. I connected the factory sender to it's wire and wiretied the senders and fitting out of the way so it was near the brake lines. I then finished the oil change. I checked the oil level after I let the car run for a bit, checking for leaks, and found the level to be just a tad below the max fill line, which is where it should be. I had found no leaks anywhere in any of my work and went on to finish wiring up the guage. I temporarly ran ground and power to the gauge. Having hooked up all the necessary wires and done everything I thought I needed to do under the hood I figured I'd test the gauge. When I started the car back up I saw that the gauge read 100 PSI. When I revved the engine up the needle climbed out of the graduated marks on the gauge.

Might there be a problem with one of the components or maybe a problem with the grounding wire for the senders? Anyone have any idea what might cause this and how I might fix it?

 

check for incorrect wiring..
make sure that the sender is grounded.. and your guage is grounded.. and that the sender wire is hooked up to the S and the power is hooked up to to I not the S or G

 

thanks... I did so and found that I had not grounded the gauge properly. When I grounded it it read somewhere around 12 PSI at idle cold and if I gave it some gas it would get up to 50 PSI or so. I haven't driven it yet so I don't know what pressure I'll get at VTEC, but it seems to be better.

Does anyone know if 12 PSI is correct or is that low for a idle pressure on startup?

 

your psi should be 12 psi at idel
50 psi >3000 rpms

70 max psi

basically you should have 10psi for every 1000 rpms

so 70 psi should be fine for up to 7000rpms

mine his 70 psi at aroun 5-6 rpm once the oil is warm

its 70 psi all the time until it warms up


[Modified by Crazydave, 11:53 PM 5/23/2002]

 

so it sounds like the preliminary findings from idle and rev to 3500 or so are about right on. I'll watch it when I warm her up and drive into VTEC and see if it raises appropriately... thanks

 

Mine is at like 75 during warm up what does that mean?
I have not had a chance to drive it yet because I still need to ground the sender