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Discussion Starter #1
New to the forum so Hello

I have a 2009 RZR 800s that is haveing a problem firing up. It turns over fine but will not fire until I have run the starter seven or more times for at least 20 seconds each. This is only for the first time of the day. Once it has started and been run around(hot) it will start pretty good but not perfect. I tried starter fluid which didn't help and also changed the plugs. While changing the plugs at night I checked for spark and they were very strange. They only sparked occasionally and were weak half the times that they did spark. As soon as it fires the first time it will run perfect but does show the check engine light. I didn't know about the codes and it is at my camp so I can't check. Any info would be greatly appreciated
Steve
 

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Lots of possibilities. You'll have to be a diagnostician and do some checking. If you don't have a service manual, get one. They are usually available on line for about $10 for a digital copy.

Weak battery will cause ignition problems, particularly when starting because the starter is drawing high amps to turn the engine over. Start by fully charging the battery and then load testing it. While you're at it check the charging system to be certain it is properly charging.

Bad connections at any wiring junctions (plugs and terminals) create resistance and reduce voltage to the ignition system. Locate and separate plugs, inspect, clean as necessary, use dielectric grease to prevent future corrosion.

Broken or damaged primary wires or wires going to the ECU, ignition switch etc. Wires can appear good from the outside but still have a broken conductor. Visual inspection and an ohmmeter are necessary to eliminate that source.

Ignition switch can be bad and cause intermittent connection. Use an ohmmeter connected to the switch terminals with all other wires disconnected and jiggle the key, switch etc. Inspect for loose wires at terminals of switch, burned or corroded terminals.

Coil wire can be bad, leaking or have corrosion where it enters the coil. Try running the engine at night while looking at the coil wire carefully to see if you can find sparks leaking to ground.

After those things are eliminated as possible causes you get into the possibility of bad components. Coils USUALLY act up when hot but it sounds like you have the opposite situation. Still, the coil can be bad. Coils can be checked with an ohmmeter, hot and cold. Resistance too low or an open is a problem.

This should get you pointed in the right direction.
 

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Discussion Starter #3
Thank you for the ideas!
A couple things I forgot to mention.
Battery is very strong (blue top Optima conversion)
Removed and cleaned large group of ground wires on frame next to battery
Removed and checked molex plugs at the ECM and coil pack
Removed and cleaned 10mm bolt going through the coil pack. Not sure if it was the coil ground point but felt it couldn't hurt.
Once I got the RZR running I jiggled the key and key switch to see if it had a bad contact inside(no change).

I'll be taking my ohm meter and a lot more knowledge with me the next time I go up to get it going. What should the meter read for the coil?

Thanks again
Steve
 

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I can't give you an exact reading, perhaps the service manual has one. Reading can vary from coil to coil because the number of winding's is different. The most important thing is if you get no continuity, that means the windings are broken. Low resistance can mean that the windings have shorted which reduced the build up of the field that induces spark when it collapses. You should also be aware that there can be an intermittent break that comes and goes with temperature change.

There are several videos on Youtube demonstrating how to check a coil. Here is one:
 

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Steve pretty much nailed most all of the possible causes for cold start problems. Despite the weak spark it might be worth your time to check fuel pressure prior to and during a cold start episode. Fuel pressure on an 09 should be 39psi minimum, should come up right after turning the key to "on" and remain at that pressure all through the run. any significant drop should be suspect. Fuel pump failures are one of the major issues with the early RZR's.

Mike
 

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I can't remember exactly what the deal was for certain, but if memory serves me at all it seems a while back there was a post where someone was having trouble with ignition timing and spark and it turned out to be something to do with the flywheel and one way starter clutch (sprag clutch).

This may be the post I am referring to: http://www.prcforum.com/forum/24-ranger-technical/111345-2015-ranger-xp900-cranks-fine-won-t-start-up.html

I don't know whether the 800s have this system or not. Perhaps Toxic will chime in and tell us more about it.

Based upon a couple of Youtube videos it doesn't appear that the 800 engines use the same starter system as the 900s so the post above probably doesn't apply to your situation.
 

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Discussion Starter #7
Rzr had a code 21. Replaced Crank Postion Sensor and it starts perfect now. Thanks again for the help
 
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