OPS question

[Crankme69]

My "Satndard brand" OPS that I replaced last Oct. is still running my lift pump. However my oil pressure gauge was showing 40 at idle & 50 while at cruise. This has within the last 2 days dropped of to 35 at idle & now 40 at cruise. I have not hooked up a mechanical gauge yet, nor would I even now where to tie in a mechanical gauge to do such a check???

My old OPS switch prior to swapping it out had stopped running my LP & it was showing oil pressures as high as 60 at idle & 65~70 at cruise.

Now this OPS seems to be going low on the reading, at least I hope it's just the reading & not real...?

Question, if I purchase a new AC delco OPS ACDELCO Part # D1808A {#12555492} SWITCH, F/PMP & ENG OIL PRESS IND SENSOR...and install it will I still need to do the relay modification or have they improved these new OPS switches to eliminate the need for the relay modification???

TIA,
69

 

[JMJNet]

The ACDelco will reduce your erratic reading and probably last longer although nobody can guarantee that.

Overtime, it will still have problem with passing the amp to the LP. The relay will override the OPS during run so it passes the correct amp to the LP all the time. But it still read the Oil Pressure just in case.

For 95, like mine, the OPS will run the LP during run. You don't want it to fail because it will ruin the IP.

 

[docdray]

In my opinion, best sign of failed or failing OPS. unless something weird has happened to your engine, you need to check LP operation.

 

[Crankme69]

Agreed, I have a newly acquired fuel pressure gauge thanks to brother forum member Lubo. I'm gonna go out and verify fuel pressure at idle & wot today.


I'm not real eager to play with any of the electrical portions of this truck, seems they have enough built in issues without me adding to the mix. IME anything that "I" touch or have modded in time usually turns to chit at some point down the road :mad2:


Thanks for the info :thumbsup:

B/r 69

 

[JMJNet]

Here is my suggestion, change the OPS with the ACDelco first. Then you can decide if you want to put the relay mod.

If you want to go a little expensive, the relay mod is available at Kennedy with nice harness and hook-ups. Less risk of messing things up because there is no cutting. In this case, you may want to do it while changing your OPS since the kit has a tee to put a secondary OPS. In light of how difficult it is to take off an existing OPS as a whole without the right tool (I butcher mine when I tried to install mine, it may be bad anyway).

 

[Crankme69]

Thanks JMJ I'll take a look at the Kennedy setup.

I just got done testing my LP pressures.

Idle 4 psi
cruise 3~4 psi
normal acceleration it will drop to 2 then levels back off between 3~4
WOT it will drop to zero until it shifts near 3600 rpm's then it will come back up to 1 psi

I'll prolly start another post...

 

[JMJNet]

The Kennedy setup also turn the LP on as soon as you turn the key before cranking for 15 sec. It has a button to prime after changing the fuel filter to bleed.

The only time it fails was because my connector to the fuse tap was loose or oxidized. So once in a while, I just have to make sure that it is not loose.