Quantcast
Jump to content


Recommended Posts

Posted

Ok guys, my turn...

Working on my neighbors 2017 Massimo MSU-500.  Initial complaint was it would start and run for about 10 minutes and the just die.  He replaced the fuel pump and still had the same issue.  I stopped over one day to look at it and saw that it had codes flashing on the dash; 505, 336 and 337.  We decided to get a new stator/crank sensor.  Took it apart installed the new stator/crank sensor and nothing.  It won't even start.  I checked the pins on the crank sensor plug and one was in the wrong place, so I repinned it and it still won't start.  I double checked the connectors and all is good.  I checked the wires from the ECU to the coil, good.  It appears to have spark every once and awhile but not enough to start.  I replaced the coil with a known good one and still nothing.  I bought the cables and downloaded the ECU hardware and everything looks good.  I pulled the timing cover back off to check the flywheel keyway, it is good.  I checked the timing and timing chain, good.  I checked the valve lash, good.  I have to put it back together but just wanted to post in case there is something else I should check before hand.  I checked the 9 pin connector and it is clean.  I have battery voltage on the purple wire and pins 15 and 18 on the ECU.  I pulled the air filter off and I am going to put a new plug in it just for the heck of it.  What ECU inputs would prevent it from starting?  Why would it now not start at all after replacing the stator/crank sensor? It has to be something simple.  Any help would be appreciated.

  • 3 weeks later...
Posted

the computer back up to it, I noticed I was not getting a RPM reading and was getting a CKP sensor error which meant it was not getting the correct counts. I took the flywheel cover back off to check the air gap. Not much movement but moved it as close to the inside as possible. I then compared the eBay special to the original and noticed that the wire colors were opposite of each other.  I put all back together and it still wouldn’t start. Just for the heck of it I switched the pins on the harness coming from the sensor and BOOM! She fired right up!  I would have never thought that the polarity of the sensor made a difference but it does. Just something to think about when you buy aftermarket parts

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By Adrian Domingues
      I have 31 miles on my new T-Boss 550. In order to start I put in nentural and the emerage brake on and push down on brake paddle, then trun ket and get nothing, with key still on I shift to reverase and the back to netural and it starts.  Anyone know what is happening.
      Thanks for your help
    • By Sammy
      Runs fine just putting around the yard. Get it out on the road and about a half miles it runs out of gas. Let it idle for a few minutes and it will run for another half mile and do it again. Replaced both fuel pumps and filter. Does anyone know if I can get rid of the factory fuel pump?
    • By jertex
      I bought a 2017 Stampede 900 last fall that was new, old stock with less than 5 hours on it thinking that I would be getting a relatively trouble free UTV as compared to buying a used Polaris or CanAm, or Honda, etc. It's been a little quirky, but reliable. What I thought was just a minor issue with this model, the difficulty in shifting between R, N, L, H, etc., was just a characteristic of this model is now a big problem. I had to climb two very steep trails to get to the upper meadow of our hunting property, which seemed to stress the UTV more than usual since I was carrying some lumber to work on a platform for a hunting blind, and when I went to shift into park, I felt something give and it would not shift out of low, but it did move up into high gear.  I couldn't get it to shift at all at that point and the shifter felt mushy for lack of a better word. I was able to get it down to the lodge and when I investigated, I discovered that the straight, metal tube portion of the shift cable had bent to almost 90 degrees (see pics). I'm positive that it had already had some deformation that had happened previously and it had the right amount of resistance to bend to the point where it was unusable. 
      I have two questions:
      1. I suspect that there must be some other issues that makes this UTV difficult to shift, and I'm wondering if this is a common problem and if someone could enlighten me on what could cause this to be difficult to shift?
      2. Have any of you had this happen and if so, how difficult is it to replace the shifter cable?
      Any other advice is welcome, this is the first UTV that I've ever owned, so I don't know much about working on these or maintaining them. I'm relatively capable when it comes to working on my own vehicles in general, and I'm not afraid to take things apart and get my hands dirty.
      Thanks in advance for any insight, I'll be traveling most the day so I won't get a chance to look at replies until this evening.


       
    • By OBL
      program will open in old Bud program only/ but will not go in BUDS 2 to let use program ECU problem working on has new engine/ new fuel pump/ injectors/ lines/ sensors/ crank sensor maps/ and new throttle body and injectors. machine starts runs a minute dies/ on 3 rd  try says key not recognized /we put other key in and same thing happens/wait 10 minutes, you can go again/ is there a back door in the program/ also might mention unplug temp sensor and map sensor , it will run a few minutes longer / then die again.
    • By Nick Varnes
      So I have a Bennche Bighorn 500 that I bought used a couple years ago. Was working fine until this winter when I was plowing and I think it drained the battery. And had a difficult time starting and staying running. Idle seamed really low, and would only stay running if I pushed on the throttle. So I changed the battery, and the acm valve, fuel filter and spark plug it will start up and surgery to 3k rpm but comes back down and dies, unless I give it throttle. I am getting fairly good amount of fuel from fuel pump.  It does spit at stutter right before it dies. What should I try next?
×
×
  • Create New...