Doing a Search on the 2nd generation forum, I came across this thread and read it.

DamonB has it right. The omp is a Pump. The ENGINE oil pump supplys oil to the omp, but NOT under pressure AT the OMP. You'd understand why if you look at the path of the oil from the front cover and the drain holes that prevent pressure from building up.

Try this with a mechanical OMP (or electrical). Block off three of the four output lines on the OMP. Install a clear line on the remaining line using a banjo fitting. ON the other end of that line put a mecanical gauge, like a cheap SunPro with a nylon line.

Then, just to be sure it's not the engine pump supplying pressure on the output lines, do this. Drill a hole in the fill cavity on the mechanical omp. Install a nipple and clear line on that nipple. Make the line a couple of feet long and lay it near the strut tower.

Start the engine and rev it to a couple of grand. First thing you'll notice is that no oil is coming out the line at the fill cavity of the omp. Never will come out because there is no pressure there. You can suck oil up that line to prove it's not blocked and is going to the omp fill cavity.

Second thing that will be noticed is the oil ooching up the clear line out of the output line, and the pressure on the gauge will constantly rise. I saw forty psi before the SunPro gauges nylon line seperated from the OMP output line.

The OMP is a PUMP. You'd swear there is no pressure if all four output lines are connected up, but if you block them off and just read pressure on the single line, you will see the pressure on a gauge.

Sure is an old thread to be writing about. Oh well.

 

just couldn't let this one go could you hailers?

 

I guess not, but all I know is that I want one of those tanks that HDP made.

 

Hey guys,

I got the CEL on and it gives me error #26 from the ECU, which is MOP Stepper Motor (The Right Thing on the picture), i got the "Limp Mode", others told me that it's my vacuum lines, but since the ECU flashes error #26 then it's definitely not the vacuum lines, because I replaced the vacuum lines with new silicon ones.

So what should i do exactly? Replace the Metering Oil Pump? which costs $1700 from Atkins Rotary.

The ECU also flashes :

23 Fuel Thermosensor
25 PRC Solenoid (3Way Valve)
44 Turbo Control Solenoid

Please help guys.

Thanks

 

replace the OMP with a good used unit for $50-100USD and go on with life? Why make this harder than it has to be?

 

Yeah, i've decided to go for a used good OMP.
Thanks

 

Is the OMP metering controlled by revs, or engine load, or something else? Assuming a stock engine or PFC

yes I'm bumping an old thread, sometimes it's easier to add to information than start a new thread for a simple question..

 

It’s both load and rpm dependent. I think the ECU uses input from the throttle position sensor.
Opinions differ, but that’s why I kept my OMP.
If you JUST pre-mix, unless steps are taken with a programmable ECU, when your foot comes off the throttle during deceleration your fuel stops. When fuel stops hard seal lubrication stops too. And when you think about it, that happens pretty damn often and usually at higher rpm and for extended periods.

When I installed a WI system years ago, I even began premixing at half rate (.5 oz @ gal) WITH the OMP since I no longer worry much about carbon and don’t have emissions.

 

First Gen has a linkage to the throttle. As throttle position increase, oil volume per cycle changes. This does the same thing as the stepper motor but in a more basic way. Atkins Rotary has rebuild videos for both styles of OMP. Worth watching so you can see the parts (without disassembling your own).