woodworker2001
Seaman Apprentice
- Joined
- Sep 19, 2010
- Messages
- 38
I have a 2000 Mercruiser Horizon 5.7 MPI. Serial # 0L304797 When I start it up it is running very rich. The IAC valve is staying open much longer than the other side. It also seems to have a little less power than the other side. The rpms always climb up slower on that side. Sometimes in order to get that engine to fire I will have to advance the throttle up to about half throttle while cranking the engine to get it to fire and then pull the throttle back down. It then takes a little while for it to idle smothly.
We hooked it to a diagnostic tool and here were the results. The desired fuel pressure on this motor was different as well as the fuel flow at idle was almost double the GPH from the other side. The timing was slightly retarded, but want to get the fuel issues sorted out before setting the timing. We also noticed that the pulse width is different from the other side on the injectors. The engine is idling rougher than the other side. We are leaning towards having a bad/clogged injector (or multiples). We also noticed after stopping the engine that the voltage on the fuel pressure sensor would slowly creep up until from about 1.7v to 3.5v or so. I dont know if it would have went higher with more time or not. We also noticed the IAC is significantly more open on this engine while the fuel flow and injector pulse were higher.
Does this sound correct? Are they worth pulling and sending out to one of the places like Injector Rehab to have cleaned and rebuilt? Seems like a much more economical option then new injectors. Any other suggestions. I dont mind pulling the injectors and what not, but I run charters on the boat and cant afford to take it down for a week to make the repairs and then have it not fix the issues.
Attached is a photo of the diagnostic tool results from the starboard motor which is running good (just there to show what we used as a baseline). I can probably give you rough numbers for somethings on the port motor (the problem motor) if that will help.
https://drive.google.com/file/d/1gL6NjVAAdPrqSkOpFGC2oMFJZtYzwZ38/view?usp=sharing
Thanks
Dan
We hooked it to a diagnostic tool and here were the results. The desired fuel pressure on this motor was different as well as the fuel flow at idle was almost double the GPH from the other side. The timing was slightly retarded, but want to get the fuel issues sorted out before setting the timing. We also noticed that the pulse width is different from the other side on the injectors. The engine is idling rougher than the other side. We are leaning towards having a bad/clogged injector (or multiples). We also noticed after stopping the engine that the voltage on the fuel pressure sensor would slowly creep up until from about 1.7v to 3.5v or so. I dont know if it would have went higher with more time or not. We also noticed the IAC is significantly more open on this engine while the fuel flow and injector pulse were higher.
Does this sound correct? Are they worth pulling and sending out to one of the places like Injector Rehab to have cleaned and rebuilt? Seems like a much more economical option then new injectors. Any other suggestions. I dont mind pulling the injectors and what not, but I run charters on the boat and cant afford to take it down for a week to make the repairs and then have it not fix the issues.
Attached is a photo of the diagnostic tool results from the starboard motor which is running good (just there to show what we used as a baseline). I can probably give you rough numbers for somethings on the port motor (the problem motor) if that will help.
https://drive.google.com/file/d/1gL6NjVAAdPrqSkOpFGC2oMFJZtYzwZ38/view?usp=sharing
Thanks
Dan