Logo
FULL SITE MENU

Fix - Mercruiser 5.0 - 260hp - Acceleration drops when reaching 1100rpm

Looks like the oil pressure gauge to me...haven't seen fuel pressure mentioned for a while...

The newer ECUs monitor the oil pressure but using a separate, independent path...if the engine's actual oil pressure is "fluctating", and it dips below the ECU's trigger point, then what you're describing is not unexpected...
 
Dear all, good afternoon! The search for a definitive solution continues.... I called another Mercruiser technician, after scanning and testing several engine components, he identified a problem with the module (866189T04), the water pressure sensor and the trim sensor. He brought another module and when connecting it, the engine becomes stable and no longer cuts off the starter after 10 minutes. The sensors only indicate an audible signal but are not responsible for cutting off the engine. Now I'm going to change the sensors, but regarding the module, it's more complicated because it's a very expensive part. Do you know if there's a possibility of repairing the module or if it can be replaced with another one of lesser value? I appreciate all the support and attention. Big hug!!!
 
Bummer that part is expensive

I don't know anyone that test or repairs those ECM
Current module 866189T04 has been superseded by the T07 but doesn't really matter for the most part. If it was ordered you should get the T07

Whipple superchargers says they can repair the 555, but not real sure. Could contact them and ask
 
I'd say you need to ask the new technician if the ECM is really bad or does it just have an update to its software....and then decide.

If your ECM is bad, there are several shops that can fix it...and they should also be able to provide you the software update(s) as well.

The only other option is replacing it with a used one...and that comes with its own set of concerns....
 
Did anyone notice that the issue changed once the coil was replaced?
I would look at the area that the coil is in. There are a lot of wires back there and most of the grounds are mounted on the flywheel housing. Is it possible that the tech loosened of broke a ground connection or unplugged one of the sensors?
I would definitely take a close look at that before condemning the ecm. So many eves get changed out unnecessarily only to find out it is a bad ground
 
AllDodge said:
Bummer that part is expensive

I don't know anyone that test or repairs those ECM
Current module 866189T04 has been superseded by the T07 but doesn't really matter for the most part. If it was ordered you should get the T07

Whipple superchargers says they can repair the 555, but not real sure. Could contact them and ask
Click to expand...
Good morning. Thank you for the information, I will talk to the Mercruiser technician about this possibility of repair. Best regards!
 
makomark said:
I'd say you need to ask the new technician if the ECM is really bad or does it just have an update to its software....and then decide.

If your ECM is bad, there are several shops that can fix it...and they should also be able to provide you the software update(s) as well.

The only other option is replacing it with a used one...and that comes with its own set of concerns....
Click to expand...
Good morning. Thank you for the information, I was not aware that it could be a software update problem, I will talk to the Mercruiser technician about this. Big hug!
 
chs said:
Did anyone notice that the issue changed once the coil was replaced?
I would look at the area that the coil is in. There are a lot of wires back there and most of the grounds are mounted on the flywheel housing. Is it possible that the tech loosened of broke a ground connection or unplugged one of the sensors?
I would definitely take a close look at that before condemning the ecm. So many eves get changed out unnecessarily only to find out it is a bad ground
Click to expand...
Good morning. In fact, after replacing the coil, the engine stabilized and the problem became the engine cut-off after 10 minutes of operation. The new Mercruiser technician checked the cables, connections and grounding, according to him everything is fine. I remind you that he brought another ECM and when this new ECM was installed the engine cut-off problem disappeared. According to him, the problem with the water pressure sensors and trim sensor beep on the dashboard but were not the cause of the engine cut-off. As for the grounding, I saw a wire that seemed to be a loose grounding wire and asked him to check it. He checked and reconnected the wire but said that the problem was not that because the engine cut-off problem continued, it only stopped occurring when we replaced the ECM. He suggested that before touching the ECM, we do a detailed check and test of the wiring harness as a way to try to identify the source of the problem, preventing the ECM from being repaired and causing this problem again. What do you think? Thank you very much for your attention and information sent. Big hug!
 
Back
Top