454 XL Possible MAP sensor issue?
Posted: October 26th, 2018, 2:28 am
I think I've worked out the majority of my fuel issues. About a month ago the starboard motor started throwing a "check engine" light at the helm, but I didn't think much of it. I was running the motor for approximately 10 hours, then changing the fuel filter. It would run better with fresh filters, and slowly get worse as the filters clogged. I got to the point where I could tell that the filters needed replacing. I was satisfied with the progress and could use the boat, but was still troubled with the check engine light, that never existed with fresh filters, or even clogged filters in the past.
With partially clogged filters the starboard motor would hesitate under acceleration, but always accelerated fine and give me full RPM with fresh filters. That's no longer the case. The motor now breaks up after around 2500 rpm or so, every time, fresh filters or not, still has a check engine code. Fuel pressure is good, fuel spray pattern out of the injectors looks good. I'm guessing the issue is a bad MAP sensor. What's a good way to diagnose the issue without a vacuum pump?
I was told that the motor may run better, accelerate fine, and run a little rich if I disconnect the MAP sensor. If that is true, I suppose that would be one way to diagnose the issue. Also, can the MAP sensor be cleaned? I will check the vacuum line for leaks, kinks and clogs tomorrow morning.
With partially clogged filters the starboard motor would hesitate under acceleration, but always accelerated fine and give me full RPM with fresh filters. That's no longer the case. The motor now breaks up after around 2500 rpm or so, every time, fresh filters or not, still has a check engine code. Fuel pressure is good, fuel spray pattern out of the injectors looks good. I'm guessing the issue is a bad MAP sensor. What's a good way to diagnose the issue without a vacuum pump?
I was told that the motor may run better, accelerate fine, and run a little rich if I disconnect the MAP sensor. If that is true, I suppose that would be one way to diagnose the issue. Also, can the MAP sensor be cleaned? I will check the vacuum line for leaks, kinks and clogs tomorrow morning.