OPS readings

[buddy]

I had an "HD" OPS, started noticing the LP not running all the time, would check OBD1 pin G and only had 8V when fuel pressure went away, so OPS was going out. Since new to when being pulled that OPS showed 45 constant Oil Pressure while running.

I picked up whatever Mackay had, and did relay mod, along with OPS extension with grease hose. I put a ground wire between the 1/8
grease hose fitting and the 1/4" adaptor fitting and ran it to an engine ground. Now I get 50-70psi readings.

Wondering if people noticed difference in gauge either from different brands OPS or after installing an extension?

Sometime I'll probably end up getting an AC Delco OPS to compare.

Thanks....

 

[knkreb]

I think the OPS is just an "in the ballpark" reading. Several have posted over the years vast pressure readings on dash when OPS was changed. I guess to really be sure of what you have, use a mechanical oil pressure gauge....

 

[bison]

normally the OPS is grounded trough the fitting,if the installed grease hose has no steel braid ,ground is lost,and an other means of grounding is requared between OPS and block.

On my 98 i have the OPS clamped by the fitting in a bracket bolted to a fuel filter bracket bolt.
On my other trucks the hose is internally steel braided.

 

[JMJNet]

IIRC, in the other forum, there are a few who has reported inaccurate reading for non ACDelco OPS. Hence, we always recommend the ACDelco. The non ACDelco has also reported to have early failures because they are not built on the right spec. Apparently, one person told them about it and the non ACDelco engineer did the test and confirm it. It has since been redesigned, trouble is we don't know when the redesigned hit the store since they have to deplete all the inventory.

So, if you don't mind a not so accurate reading for the gauge, like what Buddy did was to put a relay to control the LP. This is for the 94 and 95.

 

[Matt Bachand]

I wonder if because you took away alot of the work the OPS unit by design was doing, in effect it now is over sensitive to its other job??

 

[buddy]

Thanks all, just confirms that you cant trust your dash gauge if you haven't confirmed it with a mechanical gauge. Over the next couple weeks Ill try grounding in different places and at some point confirm with a real gauge.

 

[Matt Bachand]

Thanks all, just confirms that you cant trust your dash gauge if you haven't confirmed it with a mechanical gauge. Over the next couple weeks Ill try grounding in different places and at some point confirm with a real gauge.

I've NEVER read problems with oil pumps, or too much pressure issues. I wouldn't worry about it. As long as it reads ZERO after a filter change before pressure returns, its fine in my book.

 

[96 OILBURNER]

Overhaul in a 2"x2"x4" box.

 

[bison]

I wonder if because you took away alot of the work the OPS unit by design was doing, in effect it now is over sensitive to its other job??

there are 2 seperate cicuits in that OPS,none affects the other IMO