Rough running Monsoon

[99response]

When you start chasing sensors round and round it is time to look at the ECM itself.

I just had to replace mine on my LXI, took awhile to figure out what was wrong.

-Chris

[srh99vlx]

I am hoping the Malibu dealership can determine if the ECM itself is the problem. How much was a new ECM?

[WakeGirl]

Mechanic checked the timing when he changed the cap/rotors/plugs and then verified it with the software. I may have him check the thermostat, it seems to come up to around 140 or so, but it is worth a shot.

It's supposed to be 160, FWIW. But I'm not sure that the difference would be that big of a deal.

You say that it acts like it's running rich. With the way that engine management software tends to operate, I'd bet that it's actually running lean & that the ECM is trying hard to go the other way with it. It tries to compensate when something is out of whack, & many times it errs on the side of going too far. So if you're too lean, then it may go too far the other way. Now usually that applies to a properly functioning ECM that's trying to control a malfunctioning part (IE, a bad fuel pump - it will try to deliver more & more fuel as the pump gets worse & worse, & can occasionally cause an idle flair or fast idle, or a condition that feels like a boat that's running rich). I have no idea what may be the case here, but it's just another thing to think about.

[srh99vlx]

I towed the boat to the Malibu dealer today. They have three Indmar mechanics there and the service manager was pretty confident they could figure it out. He initially told me that they had a two week wait, but told me today it would probably be next week. He was going to start fresh and I am glad to have a new set of eyes looking at the boat. I should have started with them in the first place, but I didn't think it was going to be this tough to diagnose. I will keep everybody posted, it seems like there are a lot of Monsoon problems on the boards in the last few weeks.

[WakeGirl]

Best of luck, & keep us posted.

[Liquidmx]

Any new updates?

[srh99vlx]

I have been out of town this week and from what the service manager told me, it should go into one of the bays this week. I take my Boards on the 25th, so I am really hoping to have the boat shortly after that. He said they were going to start from scratch and work through there usual process to diagnose the problem.

[tlpru]

any update??

[srh99vlx]

I talked to him on Friday, he had just pulled it into the bay and was starting to look it over. He discovered a loose tracking fin, so he is going to pull the gas tank this week after he gets it running and diagnosis the engine problem and fix the tracking fin. They are closed today, so I am not sure how far he got on Friday. The dealer is about an hour and a half from where the boat is kept, so I told him to go ahead and fix the tracking fin while he had it.

[srh99vlx]

Update, the Malibu dealer thinks he has the fuel issue figured out, but he had the tank pulled to tighten up my tracking fin. Turns out there was some damage to the front bolt hole for the fin and it needs some glass work. I picked it up from his shop and took it to the glass guy which is an hours drive from the dealer (actually it is about 10 minutes from where the boat is kept). Unfortunately, the glass guy is about a week behind and might get to it next week. Then it has to go an hour back the other way to the Malibu dealer for him to put the shaft and tank back in, part of the interior and water test the boat. On top of that, he hasn't run the boat, so he isn't sure he has fixed my fuel problem yet. I have learned a lesson the hard way. I had a mechanic give the boat a once over, compression check, etc. Next time, I will have a marine surveyor check the boat out.

[ckornutiak]

Please keep us posted on the fix, my boat is doing the exact same thing.

[srh99vlx]

Boat is back at the Malibu dealership from the fiberglass shop. Boat was supposed to go back to one of the bays today or tomorrow. The dealership is closed on Mondays. I will keep you guys posted. The shop manager said that he thinks it is a fuel restriction near the metal screen that is downstream from the fuel filter. He said he has seen this before. The line will get gummed up around the periphery of the fuel line and then once the boat is running and fuel is flowing, some of the sediment or other junk in the fuel line will clog the line centrally around the metal screen. We'll see if he is right and I'll post up the findings.

[srh99vlx]

I am picking the boat up today. The service department went through the fuel system and found that the fuel pressure regulator was bad. The fuel pressure was high and the plugs had been fouled by the excess fuel. He replaced the plugs and the regulator and said that it is running well now. He also put the original IAC back in as the new IAC was the wrong unit. Big thanks to Randy at Skiers Marine outside of Birmingham, AL. If I had taken the boat to him first, this process wouldn't have been so long and arduous.