Polaris ATV Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
243 Posts
Discussion Starter #1
I've pretty much given up on this Sportsman ETX, but I'll ask again. I had a thread on my ETX will not stay running. I had a local guy work on it, and he claimed that he replaced the sending unit. Got it back and still experienced the same problems, other than it would crank whereas before it would not even start.

Took it to a dealership last week and they said it was the fuel pump. Said it was only 40 psi and should be 58 +/- 2. I decided against paying $760 for them to do it so I bought a Quantum fuel pump and installed it myself. Now it starts up very well. However, I still have annoying problems.

If I give it "good" throttle it will scoot and you'd never know anything was wrong. When I start going downhill, it will cut off. I have one hill that leads down into my trail and soon as I start down it will cut off. Sunday I tried going down it, and it cut off every time I cranked and started off. I had to put it in neutral and roll down until I was level. Then I started up and took off. Now, it's not just downhill but it's very prevalent during downhills. It will also do it right after start when I try to give it throttle or, say, when I get to the end of my dirt road and I go to turn around and take off slowly.

The thing is, this issue seems to be common from doing searches but the causes seem to be many. I've seen fuel pump, TPS, T-map, broken wires, wire harness, throttle assembly, something inside throttle making contact with each other when it shouldn't, and I'm sure there's some I've missed. The fact it cuts out on downhills says something to me; I'm just not sure what it means. It just can't be a coincidence that it dies when going downhill or angled forward.

If it's not the fuel pump, and I have to presume the new one is good, then what else am I looking for?
 

·
Registered
Joined
·
243 Posts
Discussion Starter #2
I ordered a new T-map sensor. It was not the exact part number but IS supposed to be a cross referenced part number. However, after putting the new MAP sensor it, the ATV would not start. I put the old sensor back on, and it started up. I don't understand it. I guess I will try a new Bosch sensor that is the exact same part number and see what that does.
 

·
Premium Member
Joined
·
168 Posts
Chasing those gremlins can be a pain in the a$$, I know here just lately. You replaced the fuel pump did you check the fuel pressure again after new install or is there anyway to rig up your fuel pressure gauge while operating the ATV?

My problem with my 08 Sportsman turned out to be the fuel pump assembly and the old fuel pump assembly was showing real good pressure and holding right up until it died on me.

It even fooled the ATV mechanic I took it to at first.After checking everything in the world he could check and finding no problem,he re-checked the fuel pressure again and could only get 10 psi max out of it then.

Tony
 

·
Registered
Joined
·
243 Posts
Discussion Starter #4
Chasing those gremlins can be a pain in the a$$, I know here just lately. You replaced the fuel pump did you check the fuel pressure again after new install or is there anyway to rig up your fuel pressure gauge while operating the ATV?

My problem with my 08 Sportsman turned out to be the fuel pump assembly and the old fuel pump assembly was showing real good pressure and holding right up until it died on me.

It even fooled the ATV mechanic I took it to at first.After checking everything in the world he could check and finding no problem,he re-checked the fuel pressure again and could only get 10 psi max out of it then.

Tony
No. The dealership told me the fuel pump that was on it was only 40 psi. So I brought it home and changed the fuel pump myself. After that, it cranks and idles pretty well. But it's this dang random cutting off issue that has me puzzled.
 

·
Premium Member
Joined
·
168 Posts
Chasing those gremlins can be a pain in the a$$, I know here just lately. You replaced the fuel pump did you check the fuel pressure again after new install or is there anyway to rig up your fuel pressure gauge while operating the ATV?

My problem with my 08 Sportsman turned out to be the fuel pump assembly and the old fuel pump assembly was showing real good pressure and holding right up until it died on me.

It even fooled the ATV mechanic I took it to at first.After checking everything in the world he could check and finding no problem,he re-checked the fuel pressure again and could only get 10 psi max out of it then.

Tony
No. The dealership told me the fuel pump that was on it was only 40 psi. So I brought it home and changed the fuel pump myself. After that, it cranks and idles pretty well. But it's this dang random cutting off issue that has me puzzled.
My 08 Sportsman would start up and idle just fine,sometimes you could ride it around several times in the yard and all of sudden it would shut off like you are completely out of gas. Other times start up idle just fine put it in forward gear and it would die. It always started right back up each time though. The fuel pump was what I call ghosting, playing games in my case. :|

I thought if you had a way to hook up a fuel pressure gauge and operate especially while descending down a hill watching the gauge it might give you a clue on possibly a momentary pressure drop cutting off the machine,it shouldn't drop of course if everything is working right.

Hope you figure it out because like I said gremlins are a pain in the a$$ to find at times.

Tony
 

·
Registered
Joined
·
243 Posts
Discussion Starter #6
Could valves in need of adjustment cause stalling and sputtering problems like this? When I went in the dealership a month or so ago and told them about my problems, the first thing the guy asked me was if the valves had been adjusted. They have not. I didn't think much about it since I was sure it was a fuel issue. Which it was, since they ended up telling me it was the fuel pump. Today I changed the spark plug, just for kicks, and my father said he notices the slight hesitation when giving it throttle and that it has a "kick" or "slap" when hitting the throttle. He said it sounded like the valves needed adjusting.

I guess either way, even if it has nothing to do with my other problem, it sounds like it needs the valves adjusted.
 
1 - 6 of 6 Posts
Top