3.0L stalls from 1200 to 2000 RPM

[axxe]

I have a 2007 Bayliner with a 3.0L Merc I/O. At idle, it will run real rough and stall if you try and gas it slowly between 1200 rpm and 2000 rpm. If you nail the gas it bogs and then takes off. There are no problems at cruising speed or WOT. At times, the idles will get smooth and perfect and it will run fine, and the stalling problem goes away. I replaced the gas filters, cap, rotor, and plugs. There is no corrosion in the wire boots. What is wrong? Please help. Thanks - Mark

 

[Bondo]

Re: 3.0L stalls from 1200 to 2000 RPM

Ayuh,.... Sounds like a boogered up Carb,.....

 

[nitrosteve]

Re: 3.0L stalls from 1200 to 2000 RPM

Could be a bad accelerator pump on the carby.. It squirts fuel just off idle..

 

[axxe]

Re: 3.0L stalls from 1200 to 2000 RPM

I took the carb off ond the accelerator pump works fine. It has a cold start injector. I was wonder if maybe that is causing the problem. Are there any common issues with the injector?

 

[Simoniz]

Re: 3.0L stalls from 1200 to 2000 RPM

I took the carb off ond the accelerator pump works fine. It has a cold start injector. I was wonder if maybe that is causing the problem. Are there any common issues with the injector?

I have had a similar problem and it turned out the carb was full of crud. The reason for this was that the previous owner had assembled the fuel filter (on the fuel pump) wrongly, with the spring on top of the filter so that the fuel from the tank was by passing the filter.

Even if your fuel filter is OK, I still think its worth dissasebling the carb, cleaning any debris and water from the float chamber, jets and passageways and reassembling it with new gaskets.

 

[axxe]

Re: 3.0L stalls from 1200 to 2000 RPM

The carb rebuild sounds like a plan. The only thing that gets me is that it ran fine when I put it away for the winter.

 

[bakerjet]

Re: 3.0L stalls from 1200 to 2000 RPM

if its not the carb and it has a HEI ignition then check the module.

 

[Rocky_Road]

Re: 3.0L stalls from 1200 to 2000 RPM

The carb rebuild sounds like a plan. The only thing that gets me is that it ran fine when I put it away for the winter.

This information suggests to me that the fuel left in the carb over the winter has evaporated and 'gummed' things up.

If this were mine, I would be running some Sea Foam through the gas system by adding to the tank...and if that didn't improve things, yank the carb and do the complete rebuild.

Happy boating!

 

[fishinpa]

Re: 3.0L stalls from 1200 to 2000 RPM

Best pull the carb and check for Nasties within !




fish

 

[axxe]

Re: 3.0L stalls from 1200 to 2000 RPM

I put some Marvel in a full tank of gas. I am doing a long run with it this week so I will see how it goes. If that doesn't work, I'll try the Sea Foam. If all else fails, a rebuild.

The reason I am not looking into the HEI module is because this is not an all the time problem. It's only about 1/2 the time.

 

[axxe]

Re: 3.0L stalls from 1200 to 2000 RPM

I took it for a long run last night. I used most of a full tank. What I notice is that after I come off of a long cruise, it will idle fine for a few minutes before it stalls. It does this every time. When it starts running bad, it also smells rich. Anybody think I might have a carb float problem?

 

[Bondo]

Re: 3.0L stalls from 1200 to 2000 RPM

Anybody think I might have a carb float problem?

Ayuh,... No doubt a Carb Problem,... Rebuild it,... The Whole Thing, preferably, All at once....

 

[axxe]

Re: 3.0L stalls from 1200 to 2000 RPM

I was reading another similar post on here. I am wondering if this problems may be electrical. It runs fine for a few minutes after a long cruise. Any thoughts on this?

 

[axxe]

Re: 3.0L stalls from 1200 to 2000 RPM

I had the distributor cap off and noticed rust on the 2 screws that hold the module down. I took them out and sanded the rust off. They were also somewhat loose. I put it back with dielectric grease. I ran a full tank of fuel through and it runs perfect.