Holy shit! I think you just solved all my problems...my buddy pulled this out and lost it then brought the boat to me...changed the IAC valve and got it to idle but it was somewhat ruff...huge air sucking that I thought wasn't right and engine would run ok sometimes then sometimes it wouldn't...ordering a new 1 today...
Just purchased a boat a month ago (2003 glastron gs209, 5.0 mpi 113 hours). first few voyages went great, then i got the 2 beeps once a minute same issue it seems. Thanks for posting the video, this will be my first think i look at. symptoms- rough idle and stalls sometimes at idle, the warning beeps, and smoked and smelled at idle running rich.
This was an easy fix and it did the trick. My engine idles so smooth. Found the part on amazon for $9.00 bit my local marina had two in a pack for $5.40.
Mine runs really rough when cold, you can smell all kinds of gas fumes. And it gets better when it warms up. But it also runs like a three-legged dog when you give it gas when it's cold. I would think that was not the idle air control circuit at all, but I think I might try this to see. Would have loved to have seen how yours ran prior to that part replacement
Did you clean the air cleaner. We just ran this boat WOT for the first time last week. It went right up to full rpm. No problem. What year and do you have fuel injection. I would start with the usual suspects. Plugs, ignition wires, distributor. Check our other video on the fuel box filter also. Joe
@@SealofPerfection someone told me that mpi was more standard after 2004. My buddy has an 01 that has carburetors. If you do you will have to look at a manual to see what to check. Sorry can't be of more help. If you do have carbs you will need to look at the choke system. Good luck. Joe
Any idea whether this part# is used for all 5.0 MPI engines from this period? Also, wouldn't removing the foam reveal whether it's a clogged 'muffler' causing idle problems so to rule out issues with the IAC itself? Owner of '02 Mercruiser 5.0 MPI 360hours
I have a Mercruiser 4.3; I replaced the IAC and the piece of foam, due to the thing idling rough and stalling at idle. Now it idles at 1200rpm, even when at operating temp. I removed the piece of foam and the idle speed went up. I replaced it with some rag-on-a-roll and it idles around 800rpm now. Seems weird...but working. Is this going to cause me problems?
Hi. I would suggest checking the throttle plate to see if it is sticking. I had a similar thing happen. I was laying on top of the engine and I inadvertently move the cable that controls the throttle and caused it to bind resulting at times resulting in a high idle. So try just closing the throttle plate manually by pushing on the lever where the cable connects it. See if that changes anything. Other thoughts for rough idle check the PCV valve, ignition wires cap and rotor, vacuum leaks, plugs and finally get the injectors removed and professional cleaned. Let me know if anything changes when you play with moving the throttle plate. Good luck Joe
@@joesilverbliss1721 This is awesome Joe, thank you. I'll have a look at these before I go out in it tomorrrow, and report back. That was real decent of you to add this info, thanks again friend!
After watching this video, I went to go check mine and mine was pretty dirty so I took mine out. I cleaned it and put it back in until I get another one.
Hello. Just saw your comment. I am an associate of the outdoorsman channel. Thoughts: since you have good performance at WOT fuel system is probably ok. Spark also probably ok. I guess I would check operation of the idle air valve. Perhaps it is getting stuck or not functioning when it warms up a bit. There is a circuit breaker I think on a bracket right behind it. Could check that also. The repair manual says for stalling check fuel pressure,bad gas, spark plugs, distributor cap and ignition, bent pushrods, worn cam shaft, basically everything! I would start by removing the connector to the idle air valve and see if it changes operation. If it does not change, could be it is not working. Let me know how you make out. I will keep thinking. Good luck. Joe.
Step two would be to clean the fuel injectors. I would start with a high concentration of Techron complete fuel system cleaner. Maybe one or more of the injectors are leaking fuel. I had mine professionally cleaned out of the engine, preferred. Another video, I think the Gen Ii fuel cooler, talks, about that. Some of mine were dribbling gas when they were supposed to be closed.
Another thought is to look for a vacuum leak at idle. Spray carb cleaner on intake connected hoses and fittings. Look for a change in idle. Keep the bildge blowers on for this.
Check your PCV valves. Your question prompted me to replace mine in the spring. BTW, a 2005 5.0L merceriser is pretty much the same engine as a 1999 GM truck 5.OL.
Holy shit! I think you just solved all my problems...my buddy pulled this out and lost it then brought the boat to me...changed the IAC valve and got it to idle but it was somewhat ruff...huge air sucking that I thought wasn't right and engine would run ok sometimes then sometimes it wouldn't...ordering a new 1 today...
I cleaned them once. It became soft and was sucked in. Result killed the IAC valve. That was a lessen learned
. Greetings from Holland
Just purchased a boat a month ago (2003 glastron gs209, 5.0 mpi 113 hours). first few voyages went great, then i got the 2 beeps once a minute same issue it seems.
Thanks for posting the video, this will be my first think i look at. symptoms- rough idle and stalls sometimes at idle, the warning beeps, and smoked and smelled at idle running rich.
Check your water separating fuel filter first. I have some other videos on my channel about that. Goodluck!
This was an easy fix and it did the trick. My engine idles so smooth. Found the part on amazon for $9.00 bit my local marina had two in a pack for $5.40.
Thanks for sharing that. This is not easy to find in repair and maintenance manuals
That little filter only keeps the noise down from air bypassing for IAC. Clogged up may have issue clean no issues.
This fixed my cold start, cold idle problem
Glad to help. Don't forget to like and subscribe!
I will drop my boat off this weekend..if you can have it fixed by end of weekend that be great..thanks Joe! Lol
Hahaha
Mine runs really rough when cold, you can smell all kinds of gas fumes. And it gets better when it warms up. But it also runs like a three-legged dog when you give it gas when it's cold. I would think that was not the idle air control circuit at all, but I think I might try this to see. Would have loved to have seen how yours ran prior to that part replacement
Did you clean the air cleaner. We just ran this boat WOT for the first time last week. It went right up to full rpm. No problem. What year and do you have fuel injection. I would start with the usual suspects. Plugs, ignition wires, distributor. Check our other video on the fuel box filter also. Joe
@@joesilverbliss1721 It's an 01. 6.2 mpi 3, I believe. It tends to run very poorly when cold, but then gradually improves as it warms up.
@@SealofPerfection someone told me that mpi was more standard after 2004. My buddy has an 01 that has carburetors. If you do you will have to look at a manual to see what to check. Sorry can't be of more help. If you do have carbs you will need to look at the choke system. Good luck. Joe
Any idea whether this part# is used for all 5.0 MPI engines from this period? Also, wouldn't removing the foam reveal whether it's a clogged 'muffler' causing idle problems so to rule out issues with the IAC itself? Owner of '02 Mercruiser 5.0 MPI 360hours
Yes you could run it without foam and see. As far as the sort number go to marineengine.com
I have a Mercruiser 4.3; I replaced the IAC and the piece of foam, due to the thing idling rough and stalling at idle. Now it idles at 1200rpm, even when at operating temp. I removed the piece of foam and the idle speed went up. I replaced it with some rag-on-a-roll and it idles around 800rpm now. Seems weird...but working. Is this going to cause me problems?
Hi. I would suggest checking the throttle plate to see if it is sticking. I had a similar thing happen. I was laying on top of the engine and I inadvertently move the cable that controls the throttle and caused it to bind resulting at times resulting in a high idle. So try just closing the throttle plate manually by pushing on the lever where the cable connects it. See if that changes anything. Other thoughts for rough idle check the PCV valve, ignition wires cap and rotor, vacuum leaks, plugs and finally get the injectors removed and professional cleaned. Let me know if anything changes when you play with moving the throttle plate. Good luck Joe
@@joesilverbliss1721 This is awesome Joe, thank you. I'll have a look at these before I go out in it tomorrrow, and report back. That was real decent of you to add this info, thanks again friend!
@@michaelking42 No problem happy to help. I am the elderly contributor to the Outdoorsman Channel. Good luck. Let me know if you find anything. Joe
Can you inform ohm reading across 2 pins of IAC, please? I’m reading 2,3ohm. Thanks
After watching this video, I went to go check mine and mine was pretty dirty so I took mine out. I cleaned it and put it back in until I get another one.
Good call!
What oil do you use during oil changes?
Mercury marine full synthetic. 25W-40 as recommended by the owners manual.
My boat will run 2k rpm and up but if I drop below 2k rpm it wants to die. Can this video maybe a solution?
Probably not, check the ignition system.
For years I had a whistling sound at low rpm. Turned out to be this $10 foam piece that become clogged.
Glad you got it fixed!
I have the same engine, it idles rough and stalls after 10 minutes of idling. No issues while running and WOT .. any ideas?
Hello. Just saw your comment. I am an associate of the outdoorsman channel. Thoughts: since you have good performance at WOT fuel system is probably ok. Spark also probably ok. I guess I would check operation of the idle air valve. Perhaps it is getting stuck or not functioning when it warms up a bit. There is a circuit breaker I think on a bracket right behind it. Could check that also. The repair manual says for stalling check fuel pressure,bad gas, spark plugs, distributor cap and ignition, bent pushrods, worn cam shaft, basically everything! I would start by removing the connector to the idle air valve and see if it changes operation. If it does not change, could be it is not working. Let me know how you make out. I will keep thinking. Good luck. Joe.
Step two would be to clean the fuel injectors. I would start with a high concentration of Techron complete fuel system cleaner. Maybe one or more of the injectors are leaking fuel. I had mine professionally cleaned out of the engine, preferred. Another video, I think the Gen Ii fuel cooler, talks, about that. Some of mine were dribbling gas when they were supposed to be closed.
Another thought is to look for a vacuum leak at idle. Spray carb cleaner on intake connected hoses and fittings. Look for a change in idle. Keep the bildge blowers on for this.
Check your PCV valves. Your question prompted me to replace mine in the spring. BTW, a 2005 5.0L merceriser is pretty much the same engine as a 1999 GM truck 5.OL.
@@joesilverbliss1721 thanks Joe! Ill investigate and report back :)
Part number Mercruiser 35-863829 or LNS-710-35-863829
Good ideas!