Looking for some help on 800 efi issue. Owner says it was working fine until the other day and bow it won't go over 35 mph. He doesn't know the history of the machine because he just got it in a auction. 1600 miles. Good condition. Said it starts right up and drives but doesn't have the power it should and won't go over 35 mph. Has paperwork and I'm interested in buying it but would like to know what I might be getting into. Never had this problem before and I've owned a handful of sportsmans. Also what would be a decent price to get it for as is? Thanks for the help

 

Throwing any codes or is it backfiring any at all? May be either a tps or tbap harness problem as either one could cause this loss of power. Check the connectors and wiring from the sensors for any bare spots or soft feeling wires that may have melted internally. Also check the crank position sensor harness that routes up under the throttle body. I've found shorts in wires there when they rubbed against the starter. Wouldn't rule out a clutch or belt problem either,but on something like this you need to eliminate one thing at at a time or break down and save some frustration and let Digital Wrench find it.

 

Okay sounds good I would have to buy it do all these Diagnostics though. Any idea what a good price would be for this machine as it sits

 

Also what would be the worst case scenario that could be wrong with it?

 

That's what Digital Wrench is for.. It can take away a lot of guess work, hair pulling and throwing parts at one. Usually a one hr charge at most shops and many times it's worth it. Especially on auction bikes that you don't have any history on. On a good running machine many people split the difference between trade in value and dealer price when they sell one.All depends on condition and options if any. You can use KBB as a reference.https://www.kbb.com/motorcycles/pola...icetype=retail

 

I hear what your saying, im just debating on whether or not to buy it as is. There isn't a dealer within 60 miles of the quad so I really can't take to have it scanned before i buy it. I know you really know these polaris machines so I thought you might have an idea as far as what my worst case scenario could be. Then I could make a decision if it is worth it or not. He is negotiable on the price due to this issue also

 

That's the thing on efi machines.. Too many things that it could be. All you can do at home is visible check the tps and tbap wiring harnesses for any cuts or soft spots.Sometimes wiggling harnesses can change engine idle and help narrow down wiring problems. Even a fuel pump could have suddenly dropped pressure not allowing enough fuel to the injectors. The pump should hold around 39 psi. If you have a fuel pressure tester that part can be checked. Even a clutch or belt problem may be what's limiting speed. On that you'd have to pull the clutch cover and check things out. On the sudden loss of power and speed it can be any of these mentioned above.Even a restricted fuel filter located at the front of the machine can cause problems. If the machine is clean and you can get right with the price,any machine can be repaired. It's just finding out where the problem is.The service manual can help a good bit,but it has its limitations also but it's a good cheap start that has some good trouble shooting checks if you're allowed time to look over the machine.2005 Polaris Sportsman 800 EFI Service Manual PDF Download

 

Ok thanks OPT, I'm going to try and look at it tomorrow if the guy is available. When he told me it won't go over 35 mph the first thing I thought was clutch/belt. Until I started researching it. Of course I found a bunch of threads with the same issue but none of them comment on what the fix was. Some said the same things you said about tps, tbap, clutch, voltage, airflow, fuel pressure. No fix though. Isn't there a way to read tged codes on these with a paperclip? I used to have a 04 sportsman 700 efi but I don't remember exactly how to do it

 

Another one of the problems is that it may not always throw codes on problems. That in itself can be frustrating for the home mechanic. If it happens to throw a 45,46 code for high or low input,then that's usually a t-bap wiring or connector problem.Code 22 is a tps short to ground. Normally the sensors aren't the problem,the connectors and wiring are if it's traced down to an electrical problem.The manual does show all the blink codes in the fuel injection system section. You can print this off and take it with you.

 

I am on my way now to look at the quad now, one question where is the tbap sensor? I know where the TPS sensor is but what about the tbap and I just want to be able to try and check the wiring and make sure it's even plugged in correctly