i am no stranger to chasing down EFI gremlins... i am not a mechanic but would say a more advanced DIY'er than the average... i have wired a complete gm 350/4l60e trans harness from scratch for a v8 swap into a jeep... however there was much more literature on it and the packard connections were much easier to come by.
So i get a boat with a 4stroke fuel injected yamaha (08' 90FTXR) because they were supposed to be the greatest thing since sliced bread... well in the middle of shrimping season i started having the stuck ISC valve symptoms.. diddled with it for a while but it was intermittent at first.. took it to my wifes uncles shop: no codes, ran fine for 30 minutes worked as it was supposed to blah blah. took it right from his shop to the boat ramp. wouldn't start couldn't get it to idle in neutral.. could open the throttle blades pushing in the neutral button and would run fine at about 1000-1200 rpm but as i backed it down idle got uglier and would die before i could get into neutral and back into gear...from everything i read made sense ISC was bad. found a used one off F75 though the body was different, the electrical part from the torx screws up was the same..put it on wouldn't work... took it to the place i bought it charged me 90$ diagnostic fees and told me it was bad and gave it back to me said they could tell because of the resistance was bad across the poles(what is also interesting is that yamaha does not give resistance values on this valve that i can find , and the current valve in the motor and the other 2 i have all have the same resistance values which makes me wonder if the other 2 do actually still work)..... so i bought a new one and installed it worked perfectly.. for about 10hrs of use then back to the old problems... (called the place i bought it and asked why it would stop working after only 10hrs, their response was "uhhhh not sure never had to replace one".. i about lost it)
anyways was worried ecu was bad.. thats when i found this thread and this rodbolt character, searched his name and the phrase ISC. and read him basically say the same exact thing hundreds of times over the corse of many years.. got the yds software.. wouldn't make any noise during the 3 second cycle... had no continuity on two pins of the connector... cut the ISC connector from the harness to find the two wires had broke inside the shielding maybe a 1/4" from the terminal... soldered new wires to the terminals and crimped on butt connectors temporarily... and now it works....
So i m going to bypass the original wires right to the ecm connector... now the wiring i have is copper and i have miles of it from my previous wiring shenanigans..and the original harness wires are aluminum...
so my questions are:
will the copper have any effect on the function of this valve?
and is the whole harness aluminum wire?
are there any other problem areas with the harness other than this valve?
i hear my father in my head saying to me ,"why would you only replace four wires when you know the rest of the harness is old and its going to break somewhere else"
well my answer as it usually is, if it aint broke don't fix it... though i CAN do it does not mean its FUN or i WANT to do it.. and the trout bite right now is ON FIRE....
but i will rewire the harness from scratch if it continues to foul up i refuse to spend 500sum$ on the yamaha harness. when the terminals are just over a dime a piece. and i already have a buttload of wire.
after some research i found
the connector to the ISC valve is a SUMITOMO 6189-0694 and the terminals and seals
SUMITOMO.jpg
Screen Shot 2016-06-28 at 2.32.01 PM.jpg
and the ecm connector is a JAE MX23A-34S-1 and corresponding terminals..
Screen Shot 2016-06-28 at 2.31.13 PM.jpg
Screen Shot 2016-06-28 at 2.31.32 PM.jpg
the website is corsa-technic.com if anyone is interested... thanks y'all
So i get a boat with a 4stroke fuel injected yamaha (08' 90FTXR) because they were supposed to be the greatest thing since sliced bread... well in the middle of shrimping season i started having the stuck ISC valve symptoms.. diddled with it for a while but it was intermittent at first.. took it to my wifes uncles shop: no codes, ran fine for 30 minutes worked as it was supposed to blah blah. took it right from his shop to the boat ramp. wouldn't start couldn't get it to idle in neutral.. could open the throttle blades pushing in the neutral button and would run fine at about 1000-1200 rpm but as i backed it down idle got uglier and would die before i could get into neutral and back into gear...from everything i read made sense ISC was bad. found a used one off F75 though the body was different, the electrical part from the torx screws up was the same..put it on wouldn't work... took it to the place i bought it charged me 90$ diagnostic fees and told me it was bad and gave it back to me said they could tell because of the resistance was bad across the poles(what is also interesting is that yamaha does not give resistance values on this valve that i can find , and the current valve in the motor and the other 2 i have all have the same resistance values which makes me wonder if the other 2 do actually still work)..... so i bought a new one and installed it worked perfectly.. for about 10hrs of use then back to the old problems... (called the place i bought it and asked why it would stop working after only 10hrs, their response was "uhhhh not sure never had to replace one".. i about lost it)
anyways was worried ecu was bad.. thats when i found this thread and this rodbolt character, searched his name and the phrase ISC. and read him basically say the same exact thing hundreds of times over the corse of many years.. got the yds software.. wouldn't make any noise during the 3 second cycle... had no continuity on two pins of the connector... cut the ISC connector from the harness to find the two wires had broke inside the shielding maybe a 1/4" from the terminal... soldered new wires to the terminals and crimped on butt connectors temporarily... and now it works....
So i m going to bypass the original wires right to the ecm connector... now the wiring i have is copper and i have miles of it from my previous wiring shenanigans..and the original harness wires are aluminum...
so my questions are:
will the copper have any effect on the function of this valve?
and is the whole harness aluminum wire?
are there any other problem areas with the harness other than this valve?
i hear my father in my head saying to me ,"why would you only replace four wires when you know the rest of the harness is old and its going to break somewhere else"
well my answer as it usually is, if it aint broke don't fix it... though i CAN do it does not mean its FUN or i WANT to do it.. and the trout bite right now is ON FIRE....
but i will rewire the harness from scratch if it continues to foul up i refuse to spend 500sum$ on the yamaha harness. when the terminals are just over a dime a piece. and i already have a buttload of wire.
after some research i found
the connector to the ISC valve is a SUMITOMO 6189-0694 and the terminals and seals
SUMITOMO.jpg
Screen Shot 2016-06-28 at 2.32.01 PM.jpg
and the ecm connector is a JAE MX23A-34S-1 and corresponding terminals..
Screen Shot 2016-06-28 at 2.31.13 PM.jpg
Screen Shot 2016-06-28 at 2.31.32 PM.jpg
the website is corsa-technic.com if anyone is interested... thanks y'all
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