Still having issues with '02 GTX RFI in "limp mode"

[ranga97]

So how is it fixed?

 

[jammin777]

one way is to make some longer leads with alligator clips to the battery and watch for voltage drops too low or too high of voltage when the ski acts up while riding and drops RPM. if it does the charging system is causing the mpem to go to limp mode . i had an rfi ski and would not start in water after ridden awhile and replaced and tripple checked everything including the coil as i was fuel fouling the plugs, i know someone on the net that had 2 rfi ski's do the exact same thing and turns out it was the mpem that fixed both skis. the a bad mpem can cause the coils not get enough volts to the coil thus weak spark under load and hot. i believe if i would have replaced the mpem my ski would have been fixed but traded it in on a new ski already. = info found a tad late lol!

 

[jammin777]

process of elimination, the easiest and cheapest thing to do is to check for voltage at the battery while riding and see what the voltage reads when acting up or not and then go from there.
also wouldn't be a bad idea to have a fuel pressure gauge hooked up while riding to see if anything out of the norm is happening. hopefully one of the 2 will tell the tale and we can move on. while you're at it make sure all the grounds are good. from battery to starter, from starter to mag cover and at the mag cover should be 2 ground wires from the harness.

may even check the resistance for the tps and air pressure sensor. the manual has the specs and which pins to probe on the amp 4 connector from the mpem. i heard that if the air pressure sensor gets wet with water it is ruined.
i am just listing the things that can be checked for free before you dump un needed money into it. keep us posted

 

[ranga97]

Well I just checked my injectors and they aren't dripping after priming the fuel system. I trimmed back to spark leads and put a fresh set of plugs in so I'll see how it goes this weekend. Hope you find out whats wrong with yours OP

 

[Drunkenaviator]

I know this thread is ancient now, but I FINALLY got to the bottom of that damn GTX. Turns out it was a bad MPEM. Ended up having a local expert swap a bunch of parts between my ski and a known working one to try to narrow down the problem. Confused everyone until they realized that you could "fix" the problem by tapping on the MPEM box. The ski would then run just fine for about 5 minutes before dying again. Not a cheap fix, but at least it's fixed!