D
Means usually when rich, they are slow to react/rev up, In my experience a stumble is usually a lean condition. Have you checked your fuel pressure? Could be fuel pump cutting out at a certain load, etc.
Mcx 08 nytro 1/2 to 3/4 throttle stumble.
- Thread starter Tuesday
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Means usually when rich, they are slow to react/rev up, In my experience a stumble is usually a lean condition. Have you checked your fuel pressure? Could be fuel pump cutting out at a certain load, etc.
Fuel pump is less than 1 year old. No lean poping when this happens. Will start checking things over tomorrow.
M
I may have missed it in the thread here but what are you A/Fs doing?
M5
M5
Spent about 4 hours today going over sled. Didnt really accomplish a lot.
Went into diagnostic on sled under 01- As you move the throttle numbers are normal 16-96 at wot. Did this 50-60 times and appeared normal each time with no spiking or dropping. I am not sure what this is actually monitoring.
Onto the tps. I have a manual and went through some of the basics. Manual shows you how to inspect and how to adjust/zero the tps. In inspecting you have the tps unplugged and test the 2 prongs for proper resistance. Mine was within spec. I spent the better part of 2 hours trying to get a voltage reading so I could see if it was at the proper angle/zeroed. Maybe someone that has done this can chime in. Does the tps have to be plugged back in and some how get a voltage reading from the cap wires? Sled on/off didnt make any difference.
This doesn't give me a lot of confidence to put in a new sensor as it will have to be zeroed and currently I cant get this one to give me a proper read out. Also to swap the sensor I will have to pull the charge tube at minimum which also means dropping the skid. What a pita. Even with the charge tube off there is no guarantee there will be enough room to get the 2 screws out.
When messing around if you test resistance between middle prong and either outside prong as you move throttle resistance would change. If I move throttle slowly enough resistance seemed to move linear but anytime there was a quick movement it would jump around.
I hate electrical problems esp. intermittent problems.
See how response goes might start a TPS thread.
TPS is around 80$ so not bad just a pain to change and need to get zeroing technique figured out.
New ECU is around 900$. Unfortunately the new ECU has a different plug in so if I change that I would have to splice all my wires or put in a new wiring harness. I have never messed with the wiring harness of the mcx ECU so have no idea how complicated that would be. Anyone done this before, swapped in a new ECU box?
I could always put in a boost it kit but then pretty sure my MCX datalogger would not work in conjunction? Anyone hooked up the datalogger to boost it?
Went into diagnostic on sled under 01- As you move the throttle numbers are normal 16-96 at wot. Did this 50-60 times and appeared normal each time with no spiking or dropping. I am not sure what this is actually monitoring.
Onto the tps. I have a manual and went through some of the basics. Manual shows you how to inspect and how to adjust/zero the tps. In inspecting you have the tps unplugged and test the 2 prongs for proper resistance. Mine was within spec. I spent the better part of 2 hours trying to get a voltage reading so I could see if it was at the proper angle/zeroed. Maybe someone that has done this can chime in. Does the tps have to be plugged back in and some how get a voltage reading from the cap wires? Sled on/off didnt make any difference.
This doesn't give me a lot of confidence to put in a new sensor as it will have to be zeroed and currently I cant get this one to give me a proper read out. Also to swap the sensor I will have to pull the charge tube at minimum which also means dropping the skid. What a pita. Even with the charge tube off there is no guarantee there will be enough room to get the 2 screws out.
When messing around if you test resistance between middle prong and either outside prong as you move throttle resistance would change. If I move throttle slowly enough resistance seemed to move linear but anytime there was a quick movement it would jump around.
I hate electrical problems esp. intermittent problems.
See how response goes might start a TPS thread.
TPS is around 80$ so not bad just a pain to change and need to get zeroing technique figured out.
New ECU is around 900$. Unfortunately the new ECU has a different plug in so if I change that I would have to splice all my wires or put in a new wiring harness. I have never messed with the wiring harness of the mcx ECU so have no idea how complicated that would be. Anyone done this before, swapped in a new ECU box?
I could always put in a boost it kit but then pretty sure my MCX datalogger would not work in conjunction? Anyone hooked up the datalogger to boost it?
N
You should be able to measure the TPS voltage on the Yellow wire on the MCX connector.
I think the new MCX controllers come with a connector that hooks into the main harness so no soldering of wires.
I run Boost It XIC, for data logging I use AEM AQ-1 which has eight inputs. It is hooked to measure stock injectors, RPM, TPS, MCX injectors, boost, A/F & fuel pressure. Takes a little bit of know how to hook it up and setup but sure is nicer than looking at data after a good run. Also makes troubleshooting a little easier.
If you decide to give Boost It a try I'm sure Neil will hook you up with setting that will pretty close.
I think the new MCX controllers come with a connector that hooks into the main harness so no soldering of wires.
I run Boost It XIC, for data logging I use AEM AQ-1 which has eight inputs. It is hooked to measure stock injectors, RPM, TPS, MCX injectors, boost, A/F & fuel pressure. Takes a little bit of know how to hook it up and setup but sure is nicer than looking at data after a good run. Also makes troubleshooting a little easier.
If you decide to give Boost It a try I'm sure Neil will hook you up with setting that will pretty close.
B
I had a similar problem this year with my 08 MCX Nytro. Check out the thread on snow and mud. I videoed the sound it was making. We spent countless hours fixing hoses, going over electrical, everything. Changed the MCX box, have a spare now and still nothing.
Turned out to be a wire going to the stock injector wasn't seated properly. Factory flaw. Fixed that and all was good.
Turned out to be a wire going to the stock injector wasn't seated properly. Factory flaw. Fixed that and all was good.
couple datalogger runs when acting up.
Full list of days logs.
Again
Last one
Fuel regulator fixed the stumble.
Then I was getting periods where the secondary injectors where not firing. Put on an older boost it box/kit and bingo problem gone.
Then I was getting periods where the secondary injectors where not firing. Put on an older boost it box/kit and bingo problem gone.
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P
My friend has the same problem in the same sled. So far no fixes!
P
I have an old boost- it and was thinking the same thing
Install is pretty simple. I would say the typically rear mount bobble at low end seems to be a bit less with the boost it box as well. I have not had much testing with it though. Only been out 1 trip so far this year and the snow sucked (valmount).
J
stumble
not sure what gen box I had but it was the kit they put out for 12-13 season, it did that from day one, ran ok at lower elevation but the higher you went the worse it got. the answer I went back to the prior control box. julio
not sure what gen box I had but it was the kit they put out for 12-13 season, it did that from day one, ran ok at lower elevation but the higher you went the worse it got. the answer I went back to the prior control box. julio
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