Engine stalls

[Trytten]

Looking for any ideas on an issue I've had for a couple weeks I've got a 2006 Larson with a 350 mag mpi problem is at 2500-3500 rpms the motor will missfire but below or above that range runs fine and now if I'm trolling around for a while at lower rpm the engine will stall some times and it starts hard and get a strong raw fuel smell but after it starts it'll run fine for a couple hours then do it again
list of things ive replaced in the last week
plugs
wires
fuel filter
pumped the tank dry of fuel and added new fuel 87 nonethonal with sea foam
changed iac valve
cleaned throttle body and flame arrestor
changed out fuel pump relay it was getting hot to the touch
if anyone's got any ideas it would be great I'm gonna go nuts trying to figure this out thanks

 

[Trytten]

Oh and also forgot to mention I did replace the cap and rotor same time as plugs and wires

 

[alldodge]

Could use a serial number, and assuming a Bravo drive

Need to check fuel pressure at the rail, should be 43psi at 1800 rpm. Should be able to get a loaner from the local auto store and connect it at item 18

http://www.mercruiserparts.com/bam/subassembly/31748/8093/90

 

[scoflaw]

2006 was a paint chip problem year for the Cool Fuel 3. Have a look at your pressure regulator on the CF3 unit, chips will collect there and boost your fuel pressure

 

[Bt Doctur]

look into the MAP sensor, under $50

 

[Trytten]

Thanks for the quick responses I pulled the fuel filter and lower screen also fuel pressure regulator and checked for any paint in the system didn't see anything and I haven't checked fuel pressure yet gonna try to get it on the water this week and check that on the map sensor is there anyway I can ohm it out to test my it or does anyone know of a scan tool I can buy for a couple hundred bucks

 

[alldodge]

anyone know of a scan tool I can buy for a couple hundred bucks

Could use a serial number

Maybe if I knew some more info

 

[scoflaw]

Rinda is good. You'll need the adapter for the 555 ECM

 

[Trytten]

Scoflaw any idea what one of them diagnostic tools cost and where to pick one up

 

[scoflaw]

Look on ebay. Paid close to 500 for mine with only 1 adapter, quite a while back.

 

[Trytten]

well thanks for the help guys prob solved found out my fuel pump was plugged within sand and mud wasn't allowing water to pass through around it to keep it cool and my miss fire at mid rpm range was do to a worn distributor gear hopefully helps anyone with anyone with same types of problems