pluguglyinhere

So would that show up on a diagnostic scan?

Also was your going in and out, mine shuts down then comes back up.....back and forth

stlliberator

iTrader: (1)

If its going into safe mode..it will run to 3000 rpm before it cuts out. Then it will cut it back to 1500 then it will come back to life. You might need to check the oil pressure..(hope its just the guage) That would send a safe code to shut the motor down..

dereknkathy

sucking sound is IAC stuck open. change it. they are notorious for dieing. another cut out possibility is the screen on the bottom of the tube in the tank.

pluguglyinhere

So far thanks guys, all stuff to check my questions now are

My oil pressure gauge was jumping around and it was cutting out about 3000 then kicking back in at about 1500. I could run great and did for about an hour at 1200 rpm and could kreep to around 3000 then out. Wouldnt this throw a code? I got none with the diacom software.

Next I want to check the flame arestor but where is it? I seriuosly feel dumb but I dont think I have one. I have a k&n so is there not one now.

I also want to check the anti siphon but where is it, all I can find between my tank and fuel pump is a ball valve.

I will check the screen for sure but I would also like to check vacuum hoses but again may be dumb but where are they I can not find any.

Airpacker

What is the fuel pressure at the injectors? You replaced the low pressure pump but did not mention what happens to the high pressure system when the motor goes south.

TWIN-SPINS

get a fuel pressure gage on the fuel rail,,,to check high side fuel pressure, while you water test it,,

pluguglyinhere

I am going to check the high side fuel pressure but until I locate a guage riddle me this batman.

It does seem like it is going into "safe mode". If I get on it to get on plane if goes to up then cuts out back to just more than idle and the cycle continues until I back off the throttle. I can cruise just off idle all day long no problems.

I would think this would cause a trouble code, but my diagnostic software has nothing. Everything seems fine, I did fix my loose oil pressure wire but have not water tested yet to recreate the problem. I assume I should not be reving the boat up in gear in the drive way.

What does the IAC do off idle, I know what it does at idle but what would happen (symptoms) off idle stuck open/closed at cruising or fulll throttle?

pluguglyinhere

Well I fixed the oil pressure gauge checked some other wirring and did a water test with the laptop to run the software while it did it.

I had not hooked up the software to the boat and left the trailer idling out past the no wake. It was idling fine as usual I began the climb up the throttle to about 3000 rpm no problems and I was on plane easliy. I no know that it was dogging bad the other day but I did not notice it with the cutting out so much. So I was cruising easy at 3,200 or so no problems. The engine warmed up so I pushed it to about 4200 and trimed up. It seemed a little doggy but I assumed it was where I had it trimmed and then it quit. It didnt die just cut out I backed off it picked back up and I got back up to 3000 or so again no problem.

It never did it again cruising like that so much better than the last time. Still something was not right so I turned around and got into it, trimmmed up. No cut out but felt kinda weighted down so I thought to myself I think I have some bad fuel or a clog. Then it hit me, my fuel vent.

I had a cheap ugly plastic fuel tank vent on the side of my boat. It was the only non chrome piece and was basically a hole you could put your pinky in to. I was afraid it would take in anything (water/bugs) plus I hated the white plastic. I changed it out with a nice chrome one with two 3/8 screened holes. So I said to myself I wonder if it is the vent. I stopped, unscrewed the tank fill, started back up pushed on the throttel and it jumped up on plance and took off.

I think I found the problem, I did not go far in fear of scratching the boat with cap or filling it with water. It was like I lost pasengers from the previous time.

I will be looking into the vent for kinks or plugs and it being to small.

Feel free to add any thoughts you guys have been great so far

stlliberator

iTrader: (1)

I think that your first stumble was just from the plugs being fouled a little bit from all the other times you have had it out with fuel issues..but ya not venting the fuel lines it could have not had the right pressure in the tank, causing the fuel lines to colapse. Do you have a VST tank on your mpi?

pluguglyinhere

stlliberator I do have the vst.

This all started with a few times one weekend that it cut out almost like a someone pulled the plug then put it back. It was like three times in a weekend but I backed off each time and was able to plane out and forget about it.

I found some fuel in the sea water oil and assumed, dispite the contraversy around here, and replaced it. It started better and all seemed good. I took the kids out yesterday and it would not plane out, each time I tried it cut out about 3 grand, did not die but if I left the throttle alone would vroom back up and back down. I was able to move around just off idle all day but each time it would do it. I did notice the oil pressure guage was like an erratic windshield wiper so I thought "safe mode".

I fixed that today and checked some other things, hoses and such. Took it out and it was fine but did it once, then seemed doggy. I then got the fuel vent idea and opened the gas tank fill. It was like a new boat, jumped on plane so I shut it down so the cap would not damage the boat bouncing around. I will check the vent tommorrow. I am hoping something is kinked or that it is too small causing a vacuum at high demand. i dont know