Tylerfromig
New member
I’m chasing an issue on my 2005 Mercury Optimax and I’m running out of ideas.
Symptoms:
- Runs rough at idle
- Hole shot is terrible — takes about 30 seconds to get on plane
- Once on plane, it runs great with no issues
What I’ve checked so far:
- Went through the entire fuel system and air system
- Found that when I unplug the fuel injector on cylinder #2, the engine idles smoothly
- Cleaned and flow tested all fuel and air injectors
- Swapped injectors between cylinders #2 and #4 — problem stayed on cylinder #2
- Compression on #2 is 105 PSI
- Swapped coils and spark plugs between #2 and #4 — no change
- Checked the carbon fiber reeds — all looked good with no chips or gaps
- Air pressure 90 fuel pressure 105
At this point I’m not sure where to look next. Since unplugging injector #2 smooths the idle out, it seems like that cylinder is causing the issue, but the injectors, coil, and plug don’t appear to be the problem.
Any ideas on what I should check next?
Symptoms:
- Runs rough at idle
- Hole shot is terrible — takes about 30 seconds to get on plane
- Once on plane, it runs great with no issues
What I’ve checked so far:
- Went through the entire fuel system and air system
- Found that when I unplug the fuel injector on cylinder #2, the engine idles smoothly
- Cleaned and flow tested all fuel and air injectors
- Swapped injectors between cylinders #2 and #4 — problem stayed on cylinder #2
- Compression on #2 is 105 PSI
- Swapped coils and spark plugs between #2 and #4 — no change
- Checked the carbon fiber reeds — all looked good with no chips or gaps
- Air pressure 90 fuel pressure 105
At this point I’m not sure where to look next. Since unplugging injector #2 smooths the idle out, it seems like that cylinder is causing the issue, but the injectors, coil, and plug don’t appear to be the problem.
Any ideas on what I should check next?