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2006 5.0 MPI 228 hours Bogging

S

scoopup928

New member
My engine cranks, idles and runs fine until 3200 rpm or 2700 rpm under load. At that point I can give it WOT and want get above those rpms. I have replaced the fuel filters, Distributor cap rotor and spark pugs with no change. The boat stays in the water 24/7. Even though I have bottom paint I have to pull it out and clean the prop and outdrive every couple of months In the summer. I assume the exhaust goes thru the outdrive. Is it be possible it is clogged and blocking the exhaust? Any suggestions are welcome.

Thanks,
 
I doubt the exhaust is clogged from growth...maybe a bad (burnt) exhaust flapper....

I start by checking the fuel pressure - if idle is ok, keep the gauge on in and check it under load, thru your normal RPM operating band...if the pressure isn't constant, the engine won't get enough fuel...
 
It IS possible that your hull is covered with enough marine growth to cause this.

My old 32 footer was so bad I used a 1 inch putty knife to scrape it clean! Took a lot time, swallowing water, and lots of dives under the hull to get her back to normal, but it was worth it.

Jeff
 
makomark said:
I doubt the exhaust is clogged from growth...maybe a bad (burnt) exhaust flapper....

I start by checking the fuel pressure - if idle is ok, keep the gauge on in and check it under load, thru your normal RPM operating band...if the pressure isn't constant, the engine won't get enough fuel...
Click to expand...

OK I checked the fuel pressure. It was pretty consistent 40 PSI. Turn the key on read 50, at idel 40 wot 38 disconnected the vacuum went up 5 psi.

I guess I will move on to fuel injectors.
 
scoopup928 said:
OK I checked the fuel pressure. It was pretty consistent 40 PSI. Turn the key on read 50, at idel 40 wot 38 disconnected the vacuum went up 5 psi.

I guess I will move on to fuel injectors.
Click to expand...

Pay attention.... with bad/clogged injectors you can redline your engine unloaded (in neutral). According to your first post, your engine will rev to 3200RPM unloaded, assuming you mean in neutral.

When you turn the ignition on do you hear the warning horn beep?
 
Docksidemarineservices said:
Pay attention.... with bad/clogged injectors you can redline your engine unloaded (in neutral). According to your first post, your engine will rev to 3200RPM unloaded, assuming you mean in neutral.

When you turn the ignition on do you hear the warning horn beep?
Click to expand...


No horn beeping. I just ease it in neutral up and at 3200 it bogs. if I give it more throttle the rpms don't increase just starts missing.
 
I just took the injector manifold lose all I have are the injectors in the intake manifold. For the life of me I can't get them out. Is there a trick? I can't find any video's on removing them on a 5.0 MPI.
 
It is my understanding that the shift event switch Chris mentioned in post #3 does exactly what you are experiencing. Unplug the dang thing and see what happens. Evidently the ECM doesn't care if it's plugged in or not. As I understand it, it's only purpose is to make sure someone doesn't rev it in neutral past 3200. It may be malfunctioning telling your engine you're in neutral when in fact you're not. A fairly common fault point evidently. I unplugged mine recently just to avoid this very scenario.
 
Mark S. said:
It is my understanding that the shift event switch Chris mentioned in post #3 does exactly what you are experiencing. Unplug the dang thing and see what happens. Evidently the ECM doesn't care if it's plugged in or not. As I understand it, it's only purpose is to make sure someone doesn't rev it in neutral past 3200. It may be malfunctioning telling your engine you're in neutral when in fact you're not. A fairly common fault point evidently. I unplugged mine recently just to avoid this very scenario.
Click to expand...


Where is that thing? I want to unplug it.
 
Mark S. said:
It is my understanding that the shift event switch Chris mentioned in post #3 does exactly what you are experiencing. Unplug the dang thing and see what happens. Evidently the ECM doesn't care if it's plugged in or not. As I understand it, it's only purpose is to make sure someone doesn't rev it in neutral past 3200. It may be malfunctioning telling your engine you're in neutral when in fact you're not. A fairly common fault point evidently. I unplugged mine recently just to avoid this very scenario.
Click to expand...

I unplugged something hooked to the shift linkage. Now it runs fine in neutral. I when as high as 5k without a miss. So I decided to take it for a spin . Under power it starts missing around 2600 . It will not think about planning out.
 
(Now it runs fine in neutral. I when as high as 5k without a miss.) NOT good! Check the fuel vent on the outside of the hull for a spider's nest or mud wasp nest. Substitute a separate fuel tank w/fresh gas and see what happens.

 
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