Snowmobile Fanatics banner

1 - 12 of 12 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter · #1 ·
I've been out of the sled business for about 10 years (getting married, finishing school, having kids, going broke, getting un-broke) and now I'm finally back to where I can dump some money into my oldest true love, aka SLEDS![:D]

So, I went back to what I know: Those beautiful Indy wedges (am I getting old, or are these newer sleds BUTT UGLY?? [Disappointed]). Bought this '92 Indy 500 SKS EFI a month or so back as part of a package deal along with a '95 XLT 600 RMK. The 600 runs great, so I've been working on getting the 500 running too. I put in a new AGM battery, cleaned out the fuel lines, rail and tank, replaced the totally rotten in-tank line, then tried to fire it up. Nothing. No LED, no nothin'. So I popped the cover off the ECU and saw a blue resistor was fried. I replaced the resistor and tried again. The LED came on, but it started to fry the new resistor, so I shut 'er down.

I then grabbed another ECU off eBay, swapped the ROM chips and installed it. Now when I turn the key to start, the fuel pump cycles for a few seconds as long as I hold the key in the start position, but the LED in the "new" ECU flashes one short and then nothing. Doesn't stay on at all. If I turn the key all the way off, then back to start, same thing, the pump cycles again. I can hear the gas flowing back into the tank via the return line, so the pump is working, but from what I've read the pump should not cycle again for 10 minutes. If I then try to start it I get nothing. The "ready" light on the dash doesn't come on at all either.

Any ideas on this? Thanks!

EDIT: By the way, I tried both ROMs from both of my ECUs, no difference.
 

·
Registered
Joined
·
9,987 Posts
Check for a short in the wiring harness, typically electrical components don't just fry on their own.
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #3 ·
Ugly_old_Poo_kid said:
Check for a short in the wiring harness, typically electrical components don't just fry on their own.
Ok, thanks ugly. I'll take a look when I get a chance.
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #4 ·
Well, I checked the wiring harness, and all the wires. I couldn't find any shorts in it. Like I said, I bought a second ECU and tried it, and that one did not fry the resistor, and the fuel pump seems to work fine when I turned the key to start.

I'm going to try and connect up to the ECU with my laptop as outlined here: http://bigsnowpage.com/?page_id=2650
Any idea if that might help me determine if the ECU is good or not?
 

·
Registered
Joined
·
9,987 Posts
That can help tell if the ECU is running properly, but if there is a power or ground issue outside the ECU it can still look like the ECU is the issue.
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #6 ·
Ok, thanks Ugly. I'll keep poking around. This has become a sort of labor of love for me. I've replaced all the suspension bearings in this machine now, so even if it takes a while to get 'er running, I'm lovin' it! And if worse comes to worse, my dad has an old 488 Trail that is on it's last legs I could scavenge the carbs and fuel pump off from and convert this machine to carbs.
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #7 ·
Ok, got my laptop hooked up to it. I was able to connect if I held the key in the start position. I'm attaching a screen shot of SelectMonitor and the results it was giving me:

20131014231449672_42321.png

The thing that stands out to me is the voltage there at a big fat zero. Am I correct in assuming that this suggests what you've been saying, Ugly, that I have a loose wire somewhere and I'm not getting a ground or a hot into one of the ECU wires? Any ideas on exactly which wire that might be? Could I hotwire it to see if I get voltage? Or could it be my key is bad?
 

·
Registered
Joined
·
9,987 Posts
That is definitely an issue, and I'm assuming in the harness.

Here is 2 schematics to follow, one will fit your machine. Check all of the 12v inputs to your ECU, and follow any that doesn't have voltage them back to where it breaks.

201112554231109_18890.jpg 201111361710417_18890.jpg
 

Attachments

·
Registered
Joined
·
12 Posts
Discussion Starter · #9 ·
Great, thanks for the schematics, Ugly. I was out sick from work yesterday (what a shame! [;)]) so I decided to start tracing out the 1992 500 EFI wiring diagram in Inkscape so I could have it in a zoom-able, colorized vector format. I tracked down the Polaris '85 to '95 body electrical manual and found the exact diagram in there for the '92 500 EFI. I then spent about 7 hours on it, and by the end I had maybe 75% of it done, including multi-colored lines for the different wire colors (what else could I do stuck in my bedroom all day?) Don't know if that would be useful to anyone else, but it has sure helped me to quickly zoom in and see exactly where the different colored wires are going.

Anyway, after seeing where things are going, I checked out the Self Shut Off Relay, and it appears to be fried. My question now is would that have been fried by the same thing that fried my ECU resistor? If I just replace that relay, will it fry my ECU again?
 

·
Registered
Joined
·
12 Posts
Discussion Starter · #10 ·
She LIVES!!!

Well, it was indeed the self shut off relay. I just peeled the blue plastic cap off it and noticed the contact was stuck in the open position, so I pried on it with a little screwdriver to pop it loose and VOILA!!! She runs! I'm going to seal it back up with some silicon since I had to break the cap edges to get it open, but it should work out for me now. I've ordered an extra one off eBay just to have on hand for an extra.

You can check out my little video here to see it in action:


So, a big thanks to Ugly_old_Poo_kid, and to all the others who've documented all the fixes for the old Polaris EFIs. Now I'm getting really itchy for some snow to fly! :)
 

·
Registered
Joined
·
9,987 Posts
Well, I was going to suggest the relay right off, but that wasn't familiar symptoms of one so I didn't and posted the schematics instead. (the twin EFI isn't my specialty, I hacked and race the triples)

But I'm glad you figured it out!! You were able to follow the schematic and trace it to there, and should be able to keep that running with minimal help, for a long time. Sweeeeeeeeet.......
 

·
Registered
Joined
·
1 Posts
Great, thanks for the schematics, Ugly. I was out sick from work yesterday (what a shame! [;)]) so I decided to start tracing out the 1992 500 EFI wiring diagram in Inkscape so I could have it in a zoom-able, colorized vector format. I tracked down the Polaris '85 to '95 body electrical manual and found the exact diagram in there for the '92 500 EFI. I then spent about 7 hours on it, and by the end I had maybe 75% of it done, including multi-colored lines for the different wire colors (what else could I do stuck in my bedroom all day?) Don't know if that would be useful to anyone else, but it has sure helped me to quickly zoom in and see exactly where the different colored wires are going.

Anyway, after seeing where things are going, I checked out the Self Shut Off Relay, and it appears to be fried. My question now is would that have been fried by the same thing that fried my ECU resistor? If I just replace that relay, will it fry my ECU again?
Do you have that colored wiring diagram still, that would be super helpful? I also have a 92 Efi and am trying to figure out the electrical.
 
1 - 12 of 12 Posts
Top