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FIXED!!! 700 Sportsman EFI Spitting, Sputtering, Dying When Ridden Hard

420K views 272 replies 62 participants last post by  lucas  
#1 · (Edited)
EDIT 6-6-2012: The conclusions in the bottom of this post are incorrect. If you want to read this post and see what my final conclusion is then go to post #148 in the link below. I recommend you read the entire thread if you can because there is a lot of good information to be had that may solve other problems (or make you think you have one :) ). http://www.polarisatvforums.com/forums/199476-post148.html

In the interest of getting all the symptoms and attempted fixes into one thread I thought I'd share about how I spent the whole summer chasing down and fixing a spitting, sputtering, quitting-while-hot issue on my '06 700 EFI. I know this is very long but I think it will be helpful to those of you that have the same symptoms.

Symptoms:
Rough idling
backfiring
hard starting when cold
cutting out when throttling up
dying after a hard run
POOR gas mileage

It started this Spring with the symptoms above. Other than rough idling and the idle RPMs seemed low; the machine would go for hours and then all of sudden it would start doing the funky chicken like it was starved for fuel. I would wait about 15-20 minutes, start it right up, and all would be well again for the next day or two.

Later I did some reading on this and other forums and found several possibilities that could cause the same symptoms: Temperature-Barometric Pressure sensor wiring broken, the sensor itself is bad, the Throttle Position Sensor is bad, its wiring broken, the fuel pump going bad, and hot gas in the tank.

I started with the simple things. I removed and cleaned the T-BAP sensor, fuel tank, fuel lines, fuel rail, and the throttle body. l also replaced the fuel filter and burned a whole tank of fuel treated with Sea Foam. Finally, when I put it back together I double checked all of the connections/clamps from the air box to the intake manifold. None of that fixed the problems.

I decided it was probably the fuel pump. I got the part number from a forum for JUST the pump without the whole friggin' tank assembly, installed it, and called it good...so I thought.

The next trip it worked fine the first day and then BAM! it happened again. Only this time there was no starting it back up so I had to suffer the shame of letting a Honda pull me 8 miles back to camp. I came back to the forums and this time I settled on the T-BAP sensor wiring harness after finding one of the wires to be broken on the inside of the insulation. I ordered a replacement from Only The Best Powersports, installed it, and you guessed it--more ridicule from my Honda friend and back to the forums.

Knowing the wiring was good I went ahead and replaced the T-BAP senor itself. Went riding again, died again, Honda towed me back again. In an unrelated issue, the Gear Position Indicator Switch went south and I had to replace that as well.

Now I turned my attention to the TPS. From the forums, I was able to learn how to check and adjust it--without the special tool and harness from Polaris. The idle voltage was a little low. I adjusted it and started the machine only to hear it keep idling like poo. I had no idea what to do until I pushed on the rubber boot between the air box and the throttle body. When I pushed on it a certain way it purred like a kitten.

I began poking around and as it turns out, there was also a wire broken in the pigtail right where it came out of the TPS. Just like the T-BAP, the insulation was still good but the strands were broken inside (I dissected it later and found it). There wasn't enough wire to work with to splice it back together so I had to replace the sensor.

Fixed, right? Wrong. It died on me the next ride but I was able to restart it after it cooled off again and get back to camp.

During my forum reading, I kept coming across threads that talked about the gas in the fuel tank getting too hot from the exhaust manifold/header and causing the fuel to boil. I dismissed this notion as I thought there was no way gas could boil in the tank without exploding.

Completely baffled, I reluctantly bought a 12" x 12" sheet of insulating foil from NAPA and covered the bottom of the gas tank

I've ridden it hard, really hard, 3 times for several hours each trip now and it runs perfectly. I don't admit it very often but I was wrong. Gas can get too hot and overheat your fuel pump, causing a significant drop in output.

All the other sensor and wiring issues were there too, but I believe it was just coincidence that they all happened at or near the same time. They would definitely cause poor gas mileage and rough idling; however; I think the primary problem causing it to die on me after some hard riding was hot gas in my fuel tank.

Here's what I think fixed the individual issues:

Fuel pump - Nothing. The old one was probably fine.

T-BAP sensor - fixed nothing. These things rarely go bad--no moving parts.

T-BAP Wiring harness - with the correct signal getting to the ECU, this fixed backfiring poor gas mileage, hard cold start and rough idle.

TPS sensor - mechanically, the sensor was probably good but I had to replace it because of where the wire was broken. Fixed backfiring, rough idling, hard starting when cold, cutting out when throttling up, POOR gas mileage.

Foil - prevented gas tank from warming up and overheating the fuel pump. Hasn't died since.

Stew
 
#3 ·
I also put a piece of insulation on the TPS to block the heat from the exhaust pipe that runs just beneath it. Don't know that it was really necessary but it gave me peace of mind.
 
#4 ·
GOOD JOB!!!

Thanks for posting up so others can benefit form the experience!!!

CW
 
#5 ·
Thanks for the post Stew. The alcohol content of today's fuel causes all sorts of problems. It lowers the boiling point, decreases mpg, corrodes fuel system components, shortens engine life and drives up food prices. The idiots in DC apparently consider all this to be a good thing. The trouble is, they are wanting to increase the % of alcohol even more.
 
#7 ·
I'm experiencing close the same problems about the sputtering and rough running. Feel like pulling my hair out. I have no CE light, replaced the coil, plugs, wires, battery, checked TPS wiring (ok, no breaks), checked TBAP wiring (ok, no breaks) and am not sure what else to do. Machine starts right up, but runs like the choke is left on (but its an EFI) and will continue running only if you are on the throttle. Grrr.

AKStew, did you have any Check Engine lights throughout any of this?
 
#8 ·
I'm experiencing close the same problems about the sputtering and rough running. Feel like pulling my hair out. I have no CE light, replaced the coil, plugs, wires, battery, checked TPS wiring (OK, no breaks), checked TBAP wiring (OK, no breaks) and am not sure what else to do. Machine starts right up, but runs like the choke is left on (but its an EFI) and will continue running only if you are on the throttle. Grrr.

AKStew, did you have any Check Engine lights throughout any of this?
WELCOME BISON!!

Have you checked the adjustment of your throttle cable? If misadjusted it will not idle..

Also wiring problems at the TBAP are many times INVISABLE!! Mine was...

CW
 
#9 ·
Cant't thank you enough for this post. My 04 700 starts and runs fine until... Who knows. Sometimes if I stop along the trail for a minute, when I restart it idles slow and rough. Whenever I try to give throttle to rev it up, it dies. Waiting about 2 minutes (truly not very long at all) it will restart and run just fine. Then seems to run beautifully. I haven't been greatly concerned because the wait to get it working again is soooo short. But I may have to try your trick and see if it stops this problem all together.
 
#10 ·
You're welcome, but I started a later thread that said my particular issue wasn't fixed.

Your problem sounds like the early stages of mine.

Since I posted this I have found poorly seated plug boots (my fault) and plug wires that were almost chafed through to the core. I fixed those and thought I had it licked...NOT! It still dies for no reason.

Now I'm moving on to the fuel pressure regulator. I'm about to post a new thread about it.

Stew
 
#13 ·
Last night, I completely dismantled the fuel system again. The tank had a trace of dirt in the bottom but nothing out of the ordinary. The filter, fuel rail and fuel lines were spotless as were the tiny little filter screens in the intake end of the injectors. The injector spray nozzles were clean as well. I also hooked up the 3-month old Airtex E8198 to its power supply outside of the tank and applied power to it for a few seconds. It ran like a banshee. Though it's possible, I don't think it's already bad. Voltage to the pump checks good when checked according to the service manual.

I got the regulator out of the fuel pump assembly everything is still intact. I couldn't see into it very well but I didn't see anything obviously bad.

There was a little red piece of plastic in the open side where the spring is. It looked like a curly-q from drilling through plastic. Coincidentally, my machine is red. Anyhow, I don't think it was causing any problems and it came right out when I blew into it.

Once I got the plastic out I pushed in on the plunger through the overflow outlet. It traveled to the overflow (dump fuel back into the tank ) position just fine. when I released it, it stuck open for a split second and then released back into the closed position.

I did this several times and it always hesitated long enough for me to get my tool out of the way before it snapped closed. I'm thinking I have a bad regulator.

Since the regulator sticks a bit when I push it in, I think the regulator gets stuck out on the trail, only more so. I think the pressure comes back when the regulator decides to let go and release back to the closed position.

Stew
 
#14 · (Edited)
I think I found an aftermarket fuel pressure regulator. Pix below.

The first photo is the OEM regulator and the second is a replacement I found at NAPA. As you can see, the NAPA regulator doesn't have the filter screen but compensates for the spacing by adding height to the main barrel and adding a little shoulder on the bypass port for the small o-ring to rest on. Having no filter screen doesn't concern me because when I removed the OEM regulator, I didn't find any dirt inside.

The OEM doesn't have a vacuum port like the replacement. In the absence of a vacuum hose, the regulator will simply reference the atmosphere which is constant. Constant atmospheric pressure equals constant fuel pressure at the regulator's specified psi...in this case 39 psi.

All the diameters are the same except that the mounting flange (the part that is the largest diameter) on the replacement regulator is 1mm less than the OEM. Being smaller is not a problem; being larger might be an issue.

NAPA isn't the only one to carry it. I went there just to get my hands on one and take some measurements. NAPA wanted $84 dollars so I ordered the Standard Motor Products part# PR210 off of eBay for $38.99 delivered. Standard Motor Products is the manufacturer for most of the other brands.

NAPA part# 219679 Echlin
O'Reilly's part# BWD 23020 Borg Warner

Again, go to any auto parts website and drill down to a 1996 Jeep Grand Cherokee fuel pressure regulator.

When I install mine I plan to do a tutorial with pix. I will explain how to check/fix the gas gauge sender as well.

Stew

OEM
Image


Potential Replacement
Image
 
#15 ·
Excellent detective work man!!

I too have found little red curly ques in strange places on my machine as well... (Mine is red too)

CW
 
#17 · (Edited)
Excellent detective work man!!

CW
Thanks, CW! For the time I spent looking at images of regulators and researching part numbers I probably should have just forked out the $500 for the tank assembly. :dunno:

Others will benefit though, and it's a matter of principle. Polaris left their customers hanging on this one. This part is easily serviceable and Polaris should demand that their fuel pump assembly supplier make the regulator and the pump available individually--nuff said.

Polman500,
I will definitely post results.

Stew
 
#16 ·
I'm interested in hearing how this pans out. My 06 800 will occasionally quit and have to be restarted right after initial start up but usually only after sitting for a while. I figured it was just that the fuel had leaked off and got air in the system. Haven't had any problems after I get going though....YET!
 
#18 · (Edited)
Someone on another forum has brought up concerns about submersing a regulator with a vacuum port on it because it is usually mounted on the fuel rail. They believe letting gas into the vacuum port side of the diaphragm wil swell up the rubber in the diaphragm and possibly cause problems.

When the regulators are otherwise identical, I personally don't think the manufacturer would make a different diaphragm for submersible versus rail-mounted regulators.

Any thoughts?

Stew
 
#19 ·
Someone on another forum has brought up concerns about submersing a regulator with a vacuum port on it because it is usually mounted on the fuel rail. They believe letting gas into the vacuum port side of the diaphragm will swell up the rubber in the diaphragm and possibly cause problems.

When the regulators are otherwise identical, I personally don't think the manufacturer would make a different diaphragm for submersible versus rail-mounted regulators.

Any thoughts?

Stew
If its not needed for this application why not simply permanently plug it?
 
#23 ·
Just got off the phone with the manufacturer's engineer. He says submersing it won't hurt it at all. He also said it should work in our application as long as the measurements are the same, which they are.

Stew
 
#25 ·
Good news and bad news. The regulator came in and it fits in the housing perfectly but...

Trying to save a few bucks I ordered it off of eBay. It was advertised as a Standard PR210 and the guy ripped me off and sent me a Chinese knockoff. Now I'm haggling with the guy to reverse his no return policy and take it back.

It has the same size specifications but is very cheaply made. The sad part is it looks more like the OEM than the Standard brand, which tells me something about where Polaris's fuel pump assembly supplier gets their parts.

Anyhow, I'm afraid to use it because I have no idea if it meets the psi specs. I'm going to do what I should have done in the first place and get the one from NAPA that I've had eyes and hands on.

Stew
 
#67 ·
Guy emailed back and final answer: No refund. He claims he had it for quite awhile and that it is an older version of the Standard PR210 regulator. This despite the statement I sent him from the design engineer at Standard, who looked at a picture I sent to him. He didn't recognize the regulator as one that Standard had ever made.

eBay says they can't do anything about it because he sent me what was in the picture on his ad and he clearly said no returns. Negative feedback is the only thing I can do, which I have.

Stew
 
#26 · (Edited)
To bad... I hate that bait and switch crap! Overall I have had excellent results and the couple times I did find these things happening I was able to get resolution thru Pay-pal/EBay.

CW
 
#27 ·
Sorry you taken like that - I hate it when they advertise one thing and send you something else - E-Bay can help you out though - it is against their policy.

I stopped at the local parts store here on my way home last night and was going to pick one up (Borg Warner part # is actually 23020 - you have a type O earlier in the thread) but decided I would wait a couple of days to see what sucess you had and they had to order it in for the next day. Cost was like $62.00 plus tax so if it does work I will go get one.

Let us know how it goes!
 
#28 · (Edited)
More good news and bad news

Well,
GOOD NEWS:
The 1996 Jeep Grand Cherokee V-8 fuel pressure regulator (NAPA 219679) fits to a tee and works like a charm. I turned the key on and let the pump pressurize the system to prime it about 6 times, then the machine fired right up like it was never dismantled and idled at about 1180 rpms...no change there. I can't confirm the fuel pressure was at 39 psi because my fuel pressure tester is on order and won't be here until next week some time.

I let it idle for about 30 minutes to let the machine get good and warm. The fan cycled on-off about 6-8 times. I can't do a real ride because it's already dark and I have to trailer about 35 miles to get to a decent riding area.

While it was running, I did a stator AC voltage output check on each of the three phases at 1300, 3000, and 5000 rpms respectively. It was right on with the specs in the manual.

BAD NEWS:
The regulator didn't fix my problem.

The problems I was having on the trail would show up in one of two ways:

1) It would slowly die and peter out while driving at any speed
2) After stopping and shutting down for a few minutes, It would start up and get to about 1000-1100 rpms and slowly peter out again.

Tonight, I turned it off after the 30-minute idle and let it sit for about 5 minutes while I tidied up the garage. When I started it up again it got a little over 1000 rpms and petered out.

I tried to start it again 3 times without success. Then I remembered I read somewhere that a guy with a similar problems poured cool fuel into the tank, it started right up and he drove away.

I only had about a quarter tank so I tried filling it up with cool fuel and it worked. Fired right up as if nothing happened.

Could it be the fuel pump overheating?

My pump is only three months old and its rated output is about 70 gallons per hour. The machine's fuel system only requires about 8 gallons per hour. What gives?

Could it be the voltage regulator? The ignition coil? The ECU?

I am completely stumped and getting a little discouraged. I've been fighting with this all summer and I'm tired of getting towed back to the truck...especially by a Honda. :)

Stew
 
#29 · (Edited)
You need to hook up your fuel pressure gauge and repeat the sequence of events from yesterday (extended idle), Also, as mentioned in a separate thread do the same with a voltmeter (or inductive amp meter) hooked to the battery to monitor battery voltage, (charging amperage). This would give some indication of what the regulator/charging system is doing during an episode.

Check again to make sure your tank vent line is not pinched, if you haven't already.
Make sure your kill switch is not somehow intermittently killing the engine.

Coils, when they fail produce a weak spark, often from heat soak. (unless they totally fail - no spark at all) The hotter they get the weaker the spark. But this does not explain the sudden change when you added cooler fresh gas. A pinched vent line would, as you removed the gas cap. Crack open the cap next time it starts to die. IF the pump is failing when hot, your pressure gauge should show reduced pressure, shouldn't it?. You already added a heat shield to bottom of tank. It is not unheard of to get faulty new parts (fuel pump). Really need to hook up that gauge.

I have also seen similar symptoms on a 1979 ford pickup. Out of the blue, it would quit as you describe. Pouring a cup or two of ice water over the spark control box on the inner fender would restore things to new until next time.

You have replaced most everything else........
 
#30 · (Edited)
My battery was at 14.23 volts at idle and 14.25 at 5000 rpms... before the episode. I didn't think to check it during.

What's a good way to check the kill switch?

After I check that, I think I need to chase down why the machine fired right up like normal just 5 minutes after I poured cool fuel into the tank. I think it's more than coincidence. That makes me think the problem is with the pump itself, and not some elusive electrical or voltage problem somewhere else on the machine. If the pump were overheating that could easily cause it to underperform.

Under normal circumstances, the pump shouldn't overheat should it? What I mean is shouldn't the pump be designed to be able to operate normally until the tank is empty? :nixweiss:

What the heck can you do about an overheating pump? I've already covered the bottom of the tank with insulating foil. I even wrapped the fuel lines with insulating foil on the parts where they were exposed to the exhaust pipe. Now they look just like the breather hose from the valve cover to the air box.

I could keep enough fuel in the tank to keep the pump submerged but that doesn't really fix the problem; and it really cuts into the usable range of the machine if I can't go below a half-tank.

I guess I need to get a pressure gauge on it and then try to duplicate the problem again. I know, :duh: My pressure tester is coming next week.

Stew
 
#34 ·
Wow Stu, you really have been around the bend with this problem. I have really learned a lot about Polaris from all of your work and patients. Thanks so much for posting all of this!

Yours,
Virginia Jake
You're welcome, Jake. Thanks for the kind words and I'm really glad this is helping people.
Stew
 
#32 ·
My problem is very similar in that after riding for a certain amount of time (as little as 20 mins in this 100 degree Texas heat up to 2+ hours in the cool of the night) and the machine would starve for fuel and die. The longer I waited to re-start it the longer it would run - If only waited 2 mins. it would start and run for about 30 seconds and die again - if left it in the field to cool off and came back an hour or two later it would start and run fine it until it heated up again. All of this made sense with theory that when fuel in the tank heated up the regulator "popped off" or stuck open and just recycled fuel inside the tank.

I was able to verify that is was not spark related and then turned to fuel issues. I do not have a shrader valve on my fuel rail so I have no way to check PSI but could verify that fuel was not under pressure in the line when removed.

biggest problem in the whole mess was you had do things quick - the longer it took me check things - the longer it had time to cool off and thus would no longer act up.

I picked up the new fuel pressure regulator (Borg Warner #23020 for O'Reiley - cost $71.00) and will install it tonight and see what happens. I will report my findings after that.

Thanks to Stew for getting us this far!
by the way Stew - my factory regulator is open (or should I say it has a hole)on the backside where the new one has the vacuum connector ???
 
#33 ·
by the way Stew - my factory regulator is open (or should I say it has a hole)on the backside where the new one has the vacuum connector ???
Check out the pictures in post #14 above. If you stuck a vacuum reference port on the OEM regulator and hooked nothing up to it, it would still work the same. I verified this with the engineer at Standard Motor Products, who makes this particular replacement regulator for most of the other brands. The port just wasn't needed for the in-tank aplication on our ATVs.

Stew
 
#36 ·
It's been suggested in another forum I'm posting in that it would be a good idea to find out with an infrared thermometer just how hot the bottom of the tank is getting when the machine dies. I think I will.

He also suggested an aluminum plate between the engine and the tank with an air gap between it and the tank, with an insulating material on top of the plate would probably do the best job of insulating the tank from the exhaust heat. This sounds like a good idea if heat is determined to be an issue, which I think it is.

Finally, he suggested having the manifold and the pipe that connects to it ceramic coated.

Thoughts anyone?

Stew
 
#37 ·
Do you have any insulation on the tank now?

To me, the heat shield you speak of may hold more heat. Only a trial period would tell.

As far as the ceramic coating, VERY EXPENSIVE!!!!!
 
#38 · (Edited)
racer, there's plenty of insulation on the tank right now. You may be right about the shield. I have to think that one through some more. Like you said, ceramic coating is expensive and I really don't want to go that route. The guy that suggested it lives in Louisiana and swears by it though.

Stew
 
#39 ·
Update...

Tonight I duplicated what I did last night. 1/4 tank of gas, idled for 30 minutes, cut it off, restarted and it ran for a couple seconds and petered out.

I had the voltmeter hooked up to the battery, and the voltage when it died it was 14.26. It jumped around a bit but AFTER the engine started to lose rpms. I don't think it's a battery problem.

Then I got my automotive stethoscope out and listened to the fuel pump on subsequent restart attempts. I placed it against the ground wire terminal on top of the fuel pump assembly since that is on top of the mounting post for the fuel pump. My sequence was: Turn key on, wait 2 seconds for priming, turn key to start, sputter a little and die.

Here's how the fuel pump sounded through the stethoscope during the priming sequences. It would begin pumping and immediately go down in pitch as if it were creating pressure. Then it would sound as if something let go and act like it was free-spinning until it turned off, after which it would stop slowly instead of cutting off sharply. I must have listened to it about 30 times and every time was the same. I also had the voltmeter hooked up to the power supply for the pump. It would show about 13v while the pump primed and go down to 5v when priming was done. That's normal.

On a failed start, the pump would attempt to spool up and pump for a second or two but then it would just begin to sound as if it were free-spinning and the engine would sputter and die. Another 30 or so tries confirmed this. Voltage was still good.

Here's what really chaps my cheeks:
After all the testing I could think of was done, I filled it up with cool gas and the machine started up like nothing ever happened.

Is it the cool gas or having the gas above a certain level that makes a difference? :nixweiss:

I siphoned the gas back out of the tank and couldn't get it to fail again after another hour of idling. BTW doesn't the owner's manual not to let it idle for extended periods?

I did listen to the pump on successful restarts. On the priming sequence, it would create a rock steady tone for 2 seconds and cut off sharply. When I would start it, it would begin to pump the same way as before then spool up to what I assume is its operating speed and stay there until I turned it off.

In sync with that was the voltage to the pump. During startup it would begin at 11.9 and quickly move up to 13.23 and stay there forever on end.

Voltage acted the same no matter what was going on. The difference was the sound of the pump both during the priming and startup sequences.

I can't explain why...anyone else care to try?

I really, REALLY need my fuel pressure tester to get here.

Thanks,
Stew