D
Duke
Well-known member
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
- Start date
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.
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
Northernboy
Member
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
brojoe
Member
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.
P
pelon
Well-known member
My friend has the same problem in the same sled. So far no fixes!
P
pelon
Well-known member
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).
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
