Optimax 225 fuel rail problem / air & fuel issues 😩

[Miagonz21]

Hi everyone, 06’ 225 Opti misfiring. Barely idles, turns off if I give it throttle. Smells like fuel, sounds like it’s running rich. New plugs. Comp test good, air 80 psi fuel 90 psi. I can hear pumps when open ignition. Tested spark, all 6 spark. When I press the schrader valve on the air side, it lets out air mixed with fuel. Checked all 3 tracker valves on fuel rail and they’re good. I believe the issue is on the fuel rail. Somehow fuel is getting on the air side. I appreciate any input! Thanks

[Miagonz21]

When turn key on, fuel press only goes to 15-20psi, air side goes up then drops right away. Should fuel / air hold pressure ? When I crack it then it goes up 76-78psi air & 86-88psi fuel

[silvertalon]

I believe when you turn off the motor, you should see pressures hold for around 30 sec's. key on engine off should show appx 90 psi at the fuel rail test valve. I'm suspecting a leak in a fuel rail. I see you are in Tampa? Has the motor been exposed to freezing temps anywhere? So I'm thinking that if for some reason cooling water doesn't drain from a fuel rail, it could freeze crack a rail? I lived in FL just north of Tampa- Crystal River. And had my well pump lines freeze and break in winter of '09. Anyway, maybe just a poor casting or porus rail? Is there fuel in the cooling water when the powerhead drains down? Sounds like a rail issue to me.

[EuropeanAM]

Hi everyone, 06’ 225 Opti misfiring. Barely idles, turns off if I give it throttle. Smells like fuel, sounds like it’s running rich. New plugs. Comp test good, air 80 psi fuel 90 psi. I can hear pumps when open ignition. Tested spark, all 6 spark. When I press the schrader valve on the air side, it lets out air mixed with fuel. Checked all 3 tracker valves on fuel rail and they’re good. I believe the issue is on the fuel rail. Somehow fuel is getting on the air side. I appreciate any input! Thanks

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Your engine has ONE tracker valve. The other two are a different part, known as the Air Pressure Regulator and the Fuel Pressure Regulator.

The Air/Fuel regulators should not be disassembled unless you have the correct tool to reassemble them.

What is the compression? What spark plugs are you running, and what to they look like?

Check Air/Fuel Pressures and record results for:

-Idle
-Under Acceleration
-5 Sec's after shutdown
-10 Sec's after shutdown
-15 Sec's after shutdown (provide results).

Check belt tensioner- spring should provide at least 75 lbs/in resistance on tensioner (with lbs/in torque wrench) BEFORE the tensioner reaches the end of it's mechanical travel.

And... when all above are proven good, Remove and inspect REEDS.

[Miagonz21]

I’ll include vin this afternoon. Spark plugs are new, factory iridium plugs. One plug looked fluffed / darker / black than the others but not too bad, it’s also difficult to tell cause they’re new. Comp is good across all 6 cyl. I checked all injectors with the multimeter testing ohms resistance. On the air side, 5 air injectors measured 1.5 ohms and 1 measured 2.0 ohms. On the fuel side all 6 measured 2.2 ohms. Will only 1 faulty air injector cause such misfire? Is there another test I should perform to confirm this injector is faulty?

[EuropeanAM]

Did you test from each pin of the DI to the metal case of the injector (or to ground)?

Computer Diagnostic Tests (Active Tests- including Auto Self Test- plugs OUT of Cylinder Heads, and/or individual Direct Injector Tests) can be helpful also.

If your resistance results on that one were repeatable, I would be suspect of that injector.