Recent content by defrag4

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    2003 Yamaha F115 ECU failure

    I just wanted to post this because this forum helped me a lot in diagnosing the issues I was having with my engine, 2003 F115 with ~950 hours started randomly sputtering, surging, and stalling above 4000RPM, running under 4000 it seemed to run fine, all signs pointed to a classic clogged VST...
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    F115 IAC not receiving signal from ECU?

    th thank you for the reply yes, i have the FSM but it does not have much info on testing the IAC/ISC I have pulled the ISC out and tried moving it with a 9v battery, I can get it to move slightly by jumping the coils, I also ohmed out the coils and they check out OK. I have also tried...
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    F115 IAC not receiving signal from ECU?

    the idle in the youtube video was good at ~750 when I shot it a few months ago, but now that we are in the heat of summer it is idling at ~500-600, Im assuming from the 95F weather with 80% humidity and the IAC not doing a damn thing to adjust and allow more of this dense air in
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    F115 IAC not receiving signal from ECU?

    2003 F115 with low idle/stalling between gears/low cold start RPM, ~650 hours on engine I cannot figure this dang IAC valve issue... Ever since buying my boat the IAC has never worked properly. I've can hear the IAC rattle on shutdown, so I know the IAC has power and is at least somewhat...
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    Tohatsu MD90B TLDI, Running poorly, Fuel pressure lower than air pressure

    nope, turns out it had spun bearings the entire time... After chasing my tail for 2months and throwing $1000 in parts at it, we finally stripped it down and found the crank bearings chewed to bits, entire block was shot, dumped the motor and went and bought a Honda moral of the story: ALWAYS...
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    2004 TLDI MD90, unable to pull any codes/engine hours and no beep when turning key, cranks up fine

    si amigo, I found the air regulator was busted and full of crud! New thread here, thanks for your help!! https://forums.iboats.com/threads/tohatsu-md90b-tldi-running-poorly-fuel-pressure-lower-than-air-pressure.742456/
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    Tohatsu MD90B TLDI, Running poorly, Fuel pressure lower than air pressure

    Welp, figured out how to remove the air and fuel regulators today, they come out with a little prying from a flat head to defeat the o-ring seals fuel regulator looked brand new, no tears or debris, seals all in good shape the air regulator on the other hand... not so hot! O-rings shredded...
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    Tohatsu MD90B TLDI, Running poorly, Fuel pressure lower than air pressure

    Figured I would start a new thread since my other issue was resolved. I am still working on getting this MD90B running, previous owner reported it ran well when he pulled it, ~8 months ago. When I got it installed on my boat I could get it to run but it was running very poorly and would die...
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    2004 TLDI MD90, unable to pull any codes/engine hours and no beep when turning key, cranks up fine

    welp I got an entire new to me (ebay used) compressor on there and still have the same problem, I had my buddy with the truck with big air compressor come back over and if we shoot air straight into the hose where the air compressor is going into the air rail, bypassing the compressor, she fires...
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    2003 40hp TLDI issues

    thanks! Ill have to give that a try, i suspect the valve is the problem as well as I have replaced everything else at this point (piston, rings, and gaskets) and shes still not building enough air to run right fingers crossed!
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    2003 40hp TLDI issues

    did you ever get this one figured out @Vwsandcar, having a similar issue with air pressure
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    2004 TLDI MD90, unable to pull any codes/engine hours and no beep when turning key, cranks up fine

    Got back out there today, found a mechanic in town who had both styles of fuel/air pressure gauges (basically AC gauges) and we pulled the fuel pressure, looked good, pulled the air pressure and it was super low ~30psi, hmmm removed the air filter, still no pressure Mechanic said he had...
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    2004 TLDI MD90, unable to pull any codes/engine hours and no beep when turning key, cranks up fine

    thanks for the reply, I will get back out there and check on those pressures tomorrow
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    2004 TLDI MD90, unable to pull any codes/engine hours and no beep when turning key, cranks up fine

    cleaned up all the wiring, cleaned all the grounds i could find, reset the TPS/ECU, and fired her back up same problem :-( let her idle for about 15 mins, still no codes the way she is jumping all over the place and responding strangely to throttle/dying when we rev her up makes me think its...
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    2004 TLDI MD90, unable to pull any codes/engine hours and no beep when turning key, cranks up fine

    Can we confirm that these battery cables are hooked up to the right spots? Can’t seem to find that in the service manual and should this air box just be sucking air here or is there a tube it should be connect too
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