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Originally Posted by Plaineman
(Post 4671422)
Thank you for your input on this... but I must let you know we did take this boat to a pro. I needed the intake (s) hoses done and did not want to spend the time or the sweat to do myself. I also had a mobil tech come by and go out for a ride.... this issue does not show up on any software. My hope here was to find someone who may have had this happen... and the video posted above is exactly what we are experiencing (interestingly they are on the exact same boat only 2 years older). I can't help but to think that when the shop was laying across the engines in order to get to those intake hoses they pinched or pulled something. I know, without a doubt I need a guy like BUP to go thru these ECU's But I still believe this problem is a hard wire issue and this boat will not run to full potential until I find it.
Anyway, I do appreciate any and all insight. Its hard to keep up as to how and what was done for testing here and ruling out issues to find any issue here. A scan tool is needed and someone whom Knows what and how to read it would be best for your issues. |
Originally Posted by BUP
(Post 4672306)
I thought you swapped both PCMs and the same issue followed to the good known running engine ? Thats what one of your post mentioned as I thought or maybe not. If so that would point to a internal PCM issue.
Its hard to keep up as to how and what was done for testing here and ruling out issues to find any issue here. A scan tool is needed and someone whom Knows what and how to read it would be best for your issues. |
Originally Posted by BUP
(Post 4672303)
If I recall this went on for a while as to what your problem was - Or am I off base on the timeframe. Anyways a scan tool tool would have picked this up on the spot with the scan parameters showing an IAC out of spec even without a warning fault and or a displayed fault code. Wanted to make it known that just because a fault is not shown does not mean too much. Its all about the parameters to find issues to help pin point
I can report the issue has not come back. He ran all last season with zero issues. Plaineman he got lucky sort of. Harness was good just the IAC. Weird it was the exact same thing you boat was doing. Careful it did fry one of his computers. https://cimg2.ibsrv.net/gimg/www.off...be6cb44a89.jpg |
couple of things 9 out 10 times when IAC connector is melted and or started smoking or even a small flame - the pcm IAC circuit internally gets taken out as well for a jist. And about 75 percent of the time as why the connector starts smoking or melts is usually poor / missed maintain in the IAC areas / related systems and or an engine over heat(s) damaging the harnesses and connections.
Also on the app 2007 Baja you posted if recall the IAC was changed out like 2 or 3 times but the problem was still there ?? I think it was that boat ? I could be wrong thou about the exact boat. If I recall his problem was over a year of that issue. Just saying |
So, as stated before... I did a PCM swap and the problem stayed with the port motor. I cannot see how this could be a computer issue if the port motor kept doing the same thing with a different computer hooked up. My bet is on some kind of a short with the main purple wire. I am back in NY but cannot wait to get back down there and look further into it.
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And again... FYI. New IAC, New crank sensor.
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I AM NOT SAYING since you swapped the PCM is bad CURRENTLY SINCE the known good engine ran good --- is this correct ?.
But lets ask what is a good running engine ? Can you reach FULL MAX rpm ? How is idle quality ? How is accelerating the rpms ? Next - has this engine been scanned. Anyways just asking Ok read and watch the OP video in the link below -- Like I said this ISSUE MORE TIMES THAN NOT IS THE ECM / PCM. Read what fixed his issue -- PCM fixed his issue. https://www.offshoreonly.com/forums/...uctuation.html |
Originally Posted by 92nsx
(Post 4672324)
Correct a couple years ago. He kept bringing it back and forth to the local shop. You would have to take it up to the local shop and there parameters and troubleshooting. After 5 trips and countless $$$$(computer, fuel pump, cam sensor, filters) in parts they threw at it, they still didn't have it fixed , . I plugged into and well didn't even need to get passed the hours screen. I could clearly see the IAC melted . I dont remember if it had 152 code or not.
I can report the issue has not come back. He ran all last season with zero issues. Plaineman he got lucky sort of. Harness was good just the IAC. Weird it was the exact same thing you boat was doing. Careful it did fry one of his computers. https://cimg2.ibsrv.net/gimg/www.off...be6cb44a89.jpg Also for all it is very important to use the Merc IAC. I know the 75 dollar aftermarket IAC looks good price wise but more times than not it does not operate exactly the same. I did side by side comparison and was shocked about this years ago and did another test last year. https://www.offshoreonly.com/forums/...uctuation.html |
To continue --- this boater sent me in his PCM 555 - He has twin 496 s. using PCM 555 -- all stock apps.
He did determine it was a BAD PCM 555 -- so he bought a new one. That fixed his issue for the time being. He sent me his BAD PCM 555 last year. Spring time I borrowed a customer s boat with the same exact engine and set up as his. Went to the lake with scan tool and so on. First off --- Ran my customers boat with scan tool hooked --- all completely good no issue and had WOT rpms. Then swapped out good known good PCM s to this BAD PCM. Did all this out on the water same day testing. Yep the same exact issue took place as in the video link below. Exactly the same issue. 100 percent it was a internal PCM issue. I fixed his bad PCM and hung on it until I could lake test the PCM swap again. Retested it out on the water and did not have the issues anymore. Watch the video - exactly same issues as you guys are mentioning. Again the boat owner whom lives many miles away from me verified it was the PCM because he bought a new PCM - his issues we gone then decided to send me his BAD PCM. Like I said his issue was - in the video link below - BAD PCM - watch the video. This is not uncommon to see this failure. Internal PCM issues |
Originally Posted by BUP
(Post 4672455)
To continue --- this boater sent me in his PCM 555 - He has twin 496 s. using PCM 555 -- all stock apps.
He did determine it was a BAD PCM 555 -- so he bought a new one. That fixed his issue for the time being. He sent me his BAD PCM 555 last year. Spring time I borrowed a customer s boat with the same exact engine and set up as his. Went to the lake with scan tool and so on. First off --- Ran my customers boat with scan tool hooked --- all completely good no issue and had WOT rpms. Then swapped out good known good PCM s to this BAD PCM. Did all this out on the water same day testing. Yep the same exact issue took place as in the video link below. Exactly the same issue. 100 percent it was a internal PCM issue. I fixed his bad PCM and hung on it until I could lake test the PCM swap again. Retested it out on the water and did not have the issues anymore. Watch the video - exactly same issues as you guys are mentioning. Again the boat owner whom lives many miles away from me verified it was the PCM because he bought a new PCM - his issues we gone then decided to send me his BAD PCM. Like I said his issue was - in the video link below - BAD PCM - watch the video. This is not uncommon to see this failure. Internal PCM issues https://www.youtube.com/watch?v=ci-FFGQ5MOI |
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