FuelInjectorMan

SkunkBoat · #1 10-13-2019, 09:58 AM

I've been troubleshooting one of my OX66 225s.

It had been running with even throttles but "stumbling" once in a while. I replaced the VST filter and that seemed to be fixed. About a week later we started with a similar problem
I have to advance the throttle further than the other to get same rpm and it tops out sooner and sometimes it jumps up or back down.
It also coughs out at idle a lot more than usual.

Verified I have spark on all cylinders.
Compression on all cylinders of both motors are 90, give or take 1.
Swapped all spark plugs from one motor to the other during the compression check process. Problem did not move to other engine so that rules out spark plugs.
I have repaired a funky connection of a coil that tricked me into thinking it was better for a run. Maybe it was a contributing factor. I ordered a replacement coil just to have for troubleshooting.

After multiple high speed runs in the river with the cover off we think its fuel flow.
I pulled out the injectors and sent them off to fuel injector man. (I think someone here recommended him)
First time ever doing this but it was quite easy.
I also ordered a filter screen that goes between the pressure regulator and the fuel rail.
Got the injectors back and installed along with a new filter behind the pressure regulator.
Pic below shows new & old filter and the filter removal tool

Made 4 runs in Manasquan River...WOW! Throttles matched up and she hauls ***. No hesitation. Never once sneezed out at idle.

Myfathersson · #2 10-13-2019, 03:28 PM

It's amazing what a cleaning can do for injectors that seem to be fine. Had a similar issue with my '01 Silverado. Replaced the entire fuel system from pump to rail and still had issues. Pulled the injectors and flushed them with carb cleaner (cuz I was too cheap to replace) and couldn't believe the change in spray pattern from start to finish. Problem solved! The old gal runs great again.

Glad you got it figured out!

SkunkBoat · #3 10-13-2019, 06:46 PM

I never did this before. Didn't even know it was a thing until some guys mentioned it on forums.
$20 a piece they got new filter, new o-ring and 2 new rubber bushings, ultrasonic cleaning and flow test. They had the work done in 1 day but expedited shipping back & forth went Monday to following Tuesday.

Its a no-brainer for an older motor thats never been done. Best done in the off season to save on shipping.

Seems cars & trucks could benefit also.