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

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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
 
#200 ·
I have made several changes: new fuel pump, insulated the tank, built a shield between the manifold and tank, insulated it, and wrapped the exhaust. It is cold here now, lows in the 20s, etc. It is still having the same symptoms, even when first started. Of course, it doesn't do this everytime. I am really scratching my head on this one. Do any of you have any advice of what I can do now. I am not so sure that it is heat related at this point.
 
#201 ·
I stopped at the local Polaris shop and spoke to the guy in service. He said that he had never heard of these conditions and thought that I had taken care of everything regarding fuel. He said that is might be the ECM. Does anyone have a source for buying this and know the part number? Do you think I am barking up the wrong tree?
 
#202 ·
Thanx for the info. I just bought an 06 800 an first ride it started dying after I ran it through some mud a little hard. So I'm gonna start with heat wrap and if that don't resolve it get the carter fuel pump.
 
#204 ·
Right now my idling and starting are good it just had the episode of spitting and dying once and I rode it alot harder after I got it started due to be aggravated at it and it ran great. So I'm hoping my pump is good to go.
 
#205 ·
I might be closing in on my problems. Even after all of the heat precautions I have taken, I am still getting hot fuel. I have ordered a laser thermometer. Can anyone tell me how hot my engine should get while running? I am wondering if I might be getting excess heat which is surpassing my shielding for the tank.
 
#207 ·
I just wanted to give an update on my atv. I recently replaced the map sensor harness plug from Only the Best. I forgot to plug the connector up and it seemed to get really hot. I assume this has something to do with the EFI making adjustments and caused it to get hot. I was also getting a check engine light with a code of 45. After I realized that I forgot to plug in the sensor, it seemed to fun great and did not get hot. I only drove it a few miles yesterday and the temperature was cool yesterday (mid 60s) but I think it might be fixed. My suggestion is to buy this harness before all of the other options. It is only 30 sum dollars and an easy installation. I will give another update after I get a good day of riding in.
 
#211 ·
OK, I have had my new Carter fuel pump now since last fall. Had good intentions of getting it in a couple times since then but always seemed to have something come up that was more important. I plowed with it all last winter (04.5 700 EFI) and had very little problems but then it was usually between 10 and 30 below F when I was plowing so that is not real conducive to heat. I did plow once when we had a pretty good dump and it was 10 F and the machine died on me when I got stuck in a pile of snow and had worked it pretty hard to get it out. When it quit all electrics died. The speedo went dead and it would not turn over. I spent a few minutes digging my self out and hit the key and everything lit up and it fired up. It took a little more rocking to pop it out of its hole but I just got it out and it died again. All power gone everything dead as dead. I pushed into the driveway and went to get my 500 to finish plowing. About 30 minutes later when I was done I went to see if it would start and it fired right up. I put it away. I continued to plow with it through the winter and once again back in March when I was plowing I pushed into a frozen pile a little faster than I should have and the machine come to an abrupt halt and died. Everything dead. I flipped the key on and off a couple times to see if I would get any juice. Finally after the third or 4th time I got juice and it started and I finished my plowing.
So flash forward to last Wednesday and my kid and his buddies wanted to go for a ride so I took the plows of both machines, topped them off with gas and we headed out. It was about 55 or 60 degrees F. We rode for about an hour. Mostly it was on an old dike at 30 40 MPH. the kids dropped down into the trees by the river and we spent about 15 minutes slow crawling through some sloppy trails to the river. The kids wanted to go out and check the meadows by the river but I new they would be wet and boggy so I told them I was going to head home. I crawled my way back out to the dike and then headed down the dike at 30 or 40 or so and the machine started to hiccup. Every 100 yards or so it would hiccup.
Now I posted previously in this thread about an issue I had last fall where it acted up just as Stew and others had written about. That is how I came to the conclusion I needed a new fuel pump. But back then it always would crank and the electrics never completely died. It just acted like it was starving for fuel until it cooled down.
I made it about 1/2 mile down the dike until it finally died completely. I had no juice at all, it was completely dead. I took the gas cap off and It was down about 2/3 to 3/4 of a tank. I couldn't tell if the gas was hot. I left the cap off and shook the machine trying to see if I could cool things off. At about 5 minutes I hit the key and the speedo lit up but when I hit the key to turn it over everything died again. About that time my son pulled up because he decided that his buddies were going to bury themselves and he had homework (good kid) to do and so I took his machine and went home to get the truck and trailer. While I was gone (about 30 minute) he tried starting it and got the power to come up a couple of times and even start once but it died almost immediately and all power gone. I tried when I got there with the trailer but still dead. 15 minutes later we were home and I thought for sure it would be cooled down and start and I could ride it off the trailer. No power. I tipped the trailer and rolled it off. Decided to try once more and turned the key. Power came on and it fired up. I rode it into the shop and it idled fine for 10 minutes before I shut it off. Battery is fully charged.
I'm sorry for the long post but I wanted to try and explain exactly what was happening.I reread this entire thread last night and have spent the last couple hours searching for references to fusible links or reseting circuit breakers. This seems to me to act like a fusible link or circuit breaker that is resetting after it cools down. I didn't find anyone who said that there machine was completely shutting down electrically when they were having issues with there pump. Has anyone had any problems with the hot fuel pump possibly kicking a circuit breaker and shutting off all power? I did find where a guy with an 03 700 with a carburetor described real similar situation to what I am having and he replaced the the circuit breakers up under the front plastic. I don't remember mine having any circuit breakers up there. I am out of town now and cant look but I cant seem to find any circuit breakers in that big mess they call a wiring diagram. Does anyone know if a 700 EFI has resetting circuit breakers and if so where are they? Thanks for your patience reading this and for any insight you can give.
 
#214 ·
Very good suggestion. I guess in my previous ramblings I didn't mention that I did check that but I think I'm going to double check that they are not only tight but clean.
 
#215 ·
Low voltage could also be causing your stalling. When the voltage gets too low, the EFI system will start doing the funky chicken. Could it be the stator isn't keeping up with the voltage demand and slowly draining the battery on long rides or when plowing a lot?

Stew
 
#216 ·
Yet another thing to look into. I hadn't thought of that. I have checked the battery voltage right after its died and It was always up in the high twelves. So it seems like things are still charging OK. The battery is fairly new and I keep it on a tender when ever parked. Any idea if the EFIs have resetting circuit breakers?
 
#217 ·
The self resetting circuit breakers are the little black fuse looking things under the access panel in your front storage box. There are also two relays that can be found under the panel that is below the headlight pod. They are one inch black cubes. The circuit breakers rarely go bad but the relays do occasionally.

Stew


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#218 ·
Thanks, I leave Nome in the morning for Fairbanks and I will dig around under there looking for them tomorrow evening when I get home. My 04 doesn't have a front storage box like my 08 does but I'm going to pull off all of that front plastic and hunt until I find them. I'm bound and determined that I'm going to get that new fuel pump put in this weekend.
Thanks again
 
#219 · (Edited)
Hi guys,
Having this exact issue so I pulled the tank, wrapped the bottom with the tin tape and ordered up a new carter pump, pn p72118 from rock auto as well as a fuel regulator for the 96 zj. The pump showed up today and it does not look like it has the right base on it.
The fuel outlet and electrical match the oem pump, but the base doesn't.

Image


Image

The two pumps have 2 completely different bases, and i don't see a way to mod the new one to fit into the plastic capsule and have the sock go back on.
Image

Now the actual pump has a number on it but not the p72118. Did they change the unit or whats up? Are there different variations of this pump? I ordered it as a direct pn not as a vehicle specific item.
 
#220 ·
Anyone have any info on this Carter pump situation?
 
#221 ·
OMG I'm having the same problem. I replaced the t-bap wiring which was frayed, still the same problem. Rode it today it died after about an hour. I removed the farrings and the gas tank was too hot to touch. Waited a few minutes and added some more gas and it started fine. Thirty minutes later I shut it off and restarted it. Did it again. I'm going to try the insulated foil, if that don't work, I'm getting rid of this 2005 700EFI ASAP!!!
 
#224 ·
I've got a Carter pump in mine & it runs great in both the heat and at high elevation.(10,000+ft) When I have mine apart I covered the entire tank with foil backed thermo-tec insulation. Its both reflective and insulating. I used foil tape on any overlap joint on the insulation. I originally took it all apart to fix the pressure regulator that was over-pressurizing the system. I used the Jeep regulator listed on the fuel pump post.
 
#225 ·
How did that fuel regulator fit for your's? Just got it today too and its garbage. No way it would work.
 
#227 · (Edited)
That is not what I have for a pump assembly. My pump is incased in a white plastic shrouding and has the regulator housing part of the assembly. It is not nice and open on my 2008 Sportsman 500 HO.