douglee25
Well-Known Member
This is slightly perplexing to me. My friend's boat has 8.1's in it (2006 40DA).
One month ago the port engine would startup fine and immediately the tach would drop to 0 rpms (for a quick second) and then return to normal idle. It typically does this just once at start, then idles fine. It runs fine on plane and you don't see the issue usually until the boat sits for some time.
Edit - It now does this on every start according to the owner. This is new.
I suspected the IAC and we replaced it. We also replaced it about 2 years ago for an immediate stall when leaving the dock for reference. We also replaced the plugs a month ago because they were due for replacement.
I thought it corrected the issue, but a few weeks later it is definitely back again. Ironically, the starboard engine is now doing the EXACT same thing. That IAC is original.
Is there something common between the two engines that I should be looking at or is this pure coincidence?
Where else should I look? This one has me slightly stumped.
One month ago the port engine would startup fine and immediately the tach would drop to 0 rpms (for a quick second) and then return to normal idle. It typically does this just once at start, then idles fine. It runs fine on plane and you don't see the issue usually until the boat sits for some time.
Edit - It now does this on every start according to the owner. This is new.
I suspected the IAC and we replaced it. We also replaced it about 2 years ago for an immediate stall when leaving the dock for reference. We also replaced the plugs a month ago because they were due for replacement.
I thought it corrected the issue, but a few weeks later it is definitely back again. Ironically, the starboard engine is now doing the EXACT same thing. That IAC is original.
Is there something common between the two engines that I should be looking at or is this pure coincidence?
Where else should I look? This one has me slightly stumped.
