1075 wont restart if it stalls?? Help
 

Starboard wants to stall when I put it in gear. Bigger problem is if I let it stall it will not restart till the next day. Turns over, have spark fuel pressure / wont even kick.. Next mooring starts right up. I can start and stop it all day, NP. Only if it stalls it will not restart. Replaced IAC,s PCM main and inline fuel filters fuel pump crank sensor oil & water temp sensors sparkplugs. Only alarm code I get is low voltage every now and then. Any one have any ideas? Or some one I can take to, I'm in Syracuse NY area. Thanks, Ken

Saris Racing is in lake George area give them a call

What is the iac % or count at idle? Not sure what you’ve tried while trying to restart but I have had erratic idles and had to adjust throttle blade opening. Also check fuel pressure regulator diaphragm. Had some leaking that would pour fuel in the intake via the boost reference line

safety neutral switch on transmission. The computer uses that for shift anticipation. Also it might be telling the computer its in gear when it really isn't

I have checked it with the scan tool, shows in and out of gear NP. + it wont turn over if it it reads in gear. Turns over no problem, just wont start un less its a few hours later. Thanks for the thought.

I have set and checked the IAC count & throttle blade position. Checked them with the scan tool + I physical watch the IAC's open when put in gear. I have opened the throttle blade in the past to get it to idle higher, but like you said it led to erratic idles. Smart craft reads 60 fuel pressure + I checked it with a gauge at the regulator, reads the same. + I tried lowering the pressure to 55 lbs., thought less fuel might idle better / no change. Don't understand the boost reference line / that's a over my head. Ill run that by my mechanic. Thanks

Thanks ill look them up.

im have seen this once before with underwater exaust and i think you exaust is towards the bottom of hull? when off plane its pretty deep it is hard to get the exaust out kinda like a vapor lock, does it start when removed from water?

Dont turn fuel pressure down on these engine. They already run lean from Mercury. Key on 60-62 psi on smartcraft for reference.

what gap did you set the crank sensor at?

Yes. Motors would not idle, sent the PCM's to Whipple for a custom program. Whipple said I would have idle issues due to under water exhaust. Whipple tried something and it helped! Port now idles in gear, Starboard still wants to stall if I leave it in gear for more than 3 seconds. Cant figure wats different about the Starboard not idling. Both motors start every time if I turn them off in the water. But if I let the Starboard stall it will not restart for hours later. I'm going to try stalling it on the trailer, then pull it out to see if it will start. Let you know?

I set the Starboard to 55 to see if it would help. No difference, so I put it right back to 60. Thanks, good info to know.

I put it as close as it would go, till I ran out of adjustment. Still seams farther away than 30 thousands. 30 is recommended yes? + I changed it out with a new one, and tried swap with the port motor.

I'm wondering if you should pull the injectors and have them tested.also,,how sure are you that the exhaust doesn't have a small leak,,almost sounds like its sucking back some water on the stall.

I'd quick hit it with starting fluid to see if it is fuel or electrical and go from there. If it fires it is fuel related if it doesn't its more than likely electrical.

The difference is longer and shorter tail pipes. If you are using turn downs try drilling two 1/2 in'' holes in turn down above the water line. Also crank sensor can be set closer to the reluctor wheel. sometimes the wheel gets magnetized over time and doesnt read. Also if you can read your IAC's. make sure the throttle linkage is set that the IAC is at like 5% in neutral.. That way it can open up to 100% to manage idle in gear. If you do put it on the trailer and shift in gear the computer will rev up the engine then bring the rpm back down, if that doesnt happen then its the safety neutral switch. Ive had it happen where the switch seemed like it was working but it was the problem

47 EXCALIBER, THANKS YOU GOT ME THINKING! I stalled the motor wile the boat was in the water, pulled it out it started right up. I was looking at the exhaust were you were talking about drilling. I ready have a 1 1/4 exhaust hose coming out the 90's. Pulled off the 1 1/4 exhaust hose to see if it was blocked maybe corroded or seaweed. the inner rubber hose was collapsed shut on both, outer hose looked great. Must have got hot at one point. Got to believe that's it! ill know next weekend. Thanks for the response!

I have a friend who had this issue with 1075 on 42 fountain and downturns. He worked back and forth with Mark Boos to sort this out. I dont remember exactly the solution but it did have to do with the length of the tailpipes and down turns, motors not liking the back pressure.
I will have to ask him what the solution was.