atv exhaust cherry red

Muskyhunter · #1 (**permalink**) 01-23-2012, 03:00 PM

I'm having a bit of an issue on my 08 touring 500 efi. Other then at idle my exhaust is going cherry red. My entire exhaust system ended up going cherry red on the night that this started, muffler incl. Luckily I hadn't melted any plastics, only the pull start suffered a little damage. There aren't any exhaust leaks, new air filter, exhaust system isn't plugged, the tank was emptied and refilled to eliminate any possible excess ethanol, tbap wiring appears to be ok from the exterior, IAT wiring appears to be ok....I try and test the wiring tonight but otherwise I'm at a loss.

The only code I get out of it is 55 Diagnostic lamp: 1. Open or short to ground 2. Short to battery

Anyone know what that means?

Thanks,

Vulcan700 · #2 (**permalink**) 01-23-2012, 03:16 PM

How did it run? sounds like a super lean condition?

Muskyhunter · #3 (**permalink**) 01-23-2012, 03:20 PM

Yeah, I forgot to mention the lean part...but it's running great. If it wasn't for the entire exhaust system going red I wouldn't suspect that there was an issue somewhere.

Vulcan700 · #4 (**permalink**) 01-23-2012, 03:24 PM

..and it is EFI.. this is the weird part?? I had a (carbed) snowmobile that had a lean condition and my muffler was glowing.. found out it was a kinked fuel line. You may want to take it in and have it looked at. you are so lucky you didn't get burned, the machine burning down or worse.

Muskyhunter · #5 (**permalink**) 01-23-2012, 03:29 PM

Yep, efi, I want to check the fuel pressure but i don't have a gauge..so i'll have to track one down. Other then being down a couple psi on fuel pressure..t-bap?

Russ C · #6 (**permalink**) 01-23-2012, 04:28 PM

needs computer re-mapped, only dealers can do it as far as I know, might also sprarycarb cleaner around throttle body boots, if engine speeds up or slows down , boots are cracked, that would make it lean

Muskyhunter · #7 (**permalink**) 01-23-2012, 05:00 PM

I've checked the boots and they look great. I just removed the fuel filter and it seems to have a little more resistance then it should so I'll put a new one in and see what happens. I checked with a polaris mechanic and he doesn't think it needs to be re-mapped, he suggested fuel pressure so that's why I started with the filter since I don't have any gauges...I'll post an update when I have a new filter.

AKStew · #8 (**permalink**) 01-24-2012, 11:06 AM

If the rubber boot, efi sensors, and computer check good, then this sounds like it could be the beginning of fuel pump problems. The OEM pumps have been known to slowly go bad over time and finally fail, probably from overheating too often while in a low fuel quantity condition.

Fuel pressure should be a constant 39 +/- 3 psi. It never changes unless the pump goes bad, nor is it adjusted by the computer. There is no fuel pressure sensor so the computer's fuel map is based on a constant pressure of fuel. The computer meters the fuel to the cylinder by controlling the amount of time per cycle each injector stays open. That time is based on sensor readings of air temp, air pressure, RPM, speed, engine temp, & crank position. Low fuel pressure or a faulty reading from any of these sensors can cause less fuel to escape from the injector on each open cycle, and therefore cause a lean condition.

You can read about the fun I had with my fuel pump here. If the pump is bad and they tell you you need to buy a whole tank, don't. There are replacement pumps available and it is pretty easy if you can turn a wrench at all. See this thread: http://www.polarisatvforums.com/forums/atv-repair-maintenance/21370-guide-servicing-fuel-pump-gauge-regulator-2006-sportsman-700-efi.html

Let us know what happens and we will go from there.

Stew

Muskyhunter · #9 (**permalink**) 01-24-2012, 01:14 PM

Thanks Stew,
That's an impressive post! I have a new filter on order and should have it tomorrow, since I'm there I might as well borrow a kit and check the pressure. Will let ya know how I make out.

Thanks,
Marty

Muskyhunter · #10 (**permalink**) 01-28-2012, 02:57 PM

Since my last post I have installed a new filter, same issue, battery connections are good, fuel pressure sits at a constant 40lbs from idle to 6000+ rpm, IAT sensor resistance is within range, there's 5 volts going to the pressure sensor and the voltage exiting will fluctuate when vacum is applied. I think I've gone as far as I can with this sensor without a diagnostic tool Could a partial break in the wiring cause this issue?