help please stalling
 

Well i just bought a 99 26' donzi with a 502 and a m3 procharger on it. It starts fine but surges really bad like 900 to 1500 but it stays running. When i put it in gear it stalls out, if i try to give it gas, or if i let it idle in gear its will stall out after about 15 seconds. I am going to change plugs tomorrow and see if that works. Does anyone have any other ideas. Also there is a beeping like every 5 seconds. All fluids are good and full and guages are all where they need to be.

How about fuel filter and fuel preasure? What kind of ignition

My guess is its a MPI? You need to hook up a scanner and see what is going on. The Alarm (beeping) needs to be addressed.

You did water test it before you bought it right? And it ran good, so this is something new?

Fuel pressure is good and it is boost referenced, i havent checked the fuel filter yet. Thanks i will check it out tomorrow.

re
 

Ya it ran good when i tested it. Im gonna do a scan on it tomorrow and see what comes back. It might be the iac valve. It surges really bad. Runs in neutral soon as i put it in gear and give it gas it stalls out.

Could be the IAC, but that would not account for the off idle issues. You say it stalls when giving it gas, thats not the IAC. Let us know, good luck

re
 

So i changed all the plugs today and it didnt fix it. So i made one one those home made led code scanners and it can back as my tps code. I went to take it off to replace it and could not find the wire harness that it plugs into. I then realized there should be wires going to it. After searching i found a unplugged wire, what do you know it goes to tps. Boat is running great other then i spit a belt off i can handle that one. Thanks every body for your input.

Glad it was a simple fix.....those are always the best :)