Snowmobile Fanatics banner

1 - 20 of 85 Posts

·
Registered
Joined
·
121 Posts
Discussion Starter · #1 ·
Hi everyone. I am in desperate need of some help here. I have tried lots of things, but I just cant get this sled to start! Here is the list thus far:

At first I couldn't get the green light to come on in the dash or the fuel pump to turn on. Now, I have the light on and the fuel pump runs when I turn the key switch all the way to the prime position, but just wont start. Doesn't even stutter.

-Battery is brand new, 12.30 volts
-Checked the pink wire on the ECM, and grounded it out and fuel pump kicks on.
-Checked brown and green fuse links which are located behind the key switch, and both show 12.3 volts
-disconnected the temp sensor, and the ECM flashes a code, then plugged back in.
-checked the blue relay with the purple , pink , and two red/w wires is the fuel pump relay. Unplug the relay and check that the two red/w wires both have power. They both are connected to the green fuse link and should have power on them at all times. They did.
-Next disconnect the ECU and check the resistance of that pink wire from the relay to the ECU with an ohmmeter. .3 ohms
-pulled out plugs and tested them, both show good spark.

As you can tell, I have been doing lots of research on this thing, and some of the things above I found online and reposted my findings.

Im stumped here, because the light comes on, the fuel pump operates, but yet when I pull it over, it doesn't start. Ive had this sled a long time, and it always started on the second pull. No such luck this time.

It has fresh gas in it. It wont even sputter at all. Makes no sense to me.

Thanks!!
Cody
 

·
Registered
Joined
·
632 Posts
when you try to start it, and it wont start, have you pulled the plugs to see if they are wet? And by that i mean is it gettin fuel, or gettin too much? check to make sure the gas is ON, and make sure the line in the tank hasnt fallen off over the summer. also try pullin a fuel line off the carb and pull it over to see if its pumpin. Have you tried dumpin a small amount of gas down the cylinders to see if it will fire? It has spark but does it have GOOD spark? Just some ideas. Good luck with it!
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #3 ·
Thanks for the reply!
I have pulled the plugs and they smell of gas, but they are not soaked.
There is no gas switch as it is an EFI.
There are no carbs only throttle bodies, so I cant pull off a fuel line because it is pressurized to 36psi.
I think I will try the fuel in the cylinder to see if she fires. Ill also check that hose in the fuel tank... that seems like a DOH move if it fell off. haha.
And yeah the spark is pretty blue, it isn't weak.
 

·
Registered
Joined
·
9,987 Posts
It's EFI so there's no fuel on/off, and you can't pull the fuel line off the carb, but you can pull it from the fuel rail..

X2 on everything else tho.

Actually an easy tell for fuel flow, is to open the gas cap and listen while the pump is running. It should be pumping a steady stream back into the tank. You can also pull the return line off of the tank and see if it pumps into a bottle.
 

·
Registered
Joined
·
632 Posts
My bad, only had one EFI and never messed with it really!
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #6 ·
Like, I said, at this point I welcome any and all responses, I just need to bounce things off of people!

Looked in the tank, looks like the line is still attached, as I used my spring puller (coathanger modified) to reach in and gently pull up towards the front. It was solid.

I poured some gas in both cylinders, and whala it fired right up! Ran for a couple seconds and then promptly died again. Did it again, and varried the throttle to hope to create some suction or something and then it died.

So, it appears I have a fuel issue. What is the next place to look at?

The fuel pump does kick on and run for the initial 5 second key turn, and then again briefly after every tug on the rope...


should I pull the fuel line off the rail and watch it shoot when I prime it with the key? Or is this a bad idea? I just dont know where to begin diagnosing this fuel issue after the fuel pump working and getting spark. I tried to check fuel pressure with my auto guage, but there isn't a shrader valve. :(
 

·
Registered
Joined
·
393 Posts
I,d pull the line and check for good pressure and volume.The pump can run but if it isn,t putting out enough pressure it isn,t going to spray out the injectors.I,m pretty sure theres a check valve in the pump to prevent leakdown in the line.I,m not overly familiar with the EFI,s but is there a pressure regulator in the line somewhere,probally off the rail to the return line?
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #8 ·
yup there is a fuel pressure regulator off the chaincase side of the fuel rail.
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #9 ·
what should I do with that pressure regulator? anything? not sure what you meant by that comment rainman56
 

·
Registered
Joined
·
127 Posts
Have a Harbor Freight near by? I picked up a great Fuel Pressure gauge. When you have the gas cap off can you hear the fuel running back into tank? If not you are probably looking at weak pressure or bad regulator.

I need to get mine out of the shed and get it started, same sled, same problems last year. Let's say I have two complete fuel rails, and pumps before I got side tracked with the 89 last year.
 

·
Registered
Joined
·
393 Posts
polarisn1 said:
what should I do with that pressure regulator? anything? not sure what you meant by that comment rainman56
Ok,first I,d pull the vacuum line off the regulator and cycle the pump.See if any fuel is coming out the vacuum port.If it is regulator is done.If not,try finding a rubber part in the return fuel line and pinch it off with a vise grips(careful not to crack it).See if it starts and run.If it does,yep regulator toast.If it still doesn,t go then your gonna have to either get a gauge and check to see if the pumps putting out enough pressure and also that it doesn,t bleed off.If the check ball/valve in the pump is bad it,ll bleed off pressure on the tank end as well.Also can,t remember if they run an external fuel filter but if so check and make sure its not something simple and plugged.
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #12 ·
tazzzdvil said:
Have a Harbor Freight near by? I picked up a great Fuel Pressure gauge. When you have the gas cap off can you hear the fuel running back into tank? If not you are probably looking at weak pressure or bad regulator.

I need to get mine out of the shed and get it started, same sled, same problems last year. Let's say I have two complete fuel rails, and pumps before I got side tracked with the 89 last year.
No I dont, but I do have an automotive gauge. I just have to figure out how to adapt it inline as there is not a shrader valve on the stupid fuel rail.

I took the gas cap off and looked inside, but I didn't see any movement in the fuel. The tank is full though, as it was driven to the gas station, filled up, and then wouldn't start.



I just checked the single black wire coming out of the CDI box and ohm'ed it to the white/red stripe wire on the ECU plug, and that was 1.2 ohms. Looks good to me.

I pulled off the vacuum line of the FPR, and a little bit of gas came out. Not much, just half a drop or so. Im gonna go try to start it with the line off and see what happens, and then try it with the return line pinched.
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #13 ·
Rainman56 said:
Ok,first I,d pull the vacuum line off the regulator and cycle the pump.See if any fuel is coming out the vacuum port.If it is regulator is done.If not,try finding a rubber part in the return fuel line and pinch it off with a vise grips(careful not to crack it).See if it starts and run.If it does,yep regulator toast.If it still doesn,t go then your gonna have to either get a gauge and check to see if the pumps putting out enough pressure and also that it doesn,t bleed off.If the check ball/valve in the pump is bad it,ll bleed off pressure on the tank end as well.Also can,t remember if they run an external fuel filter but if so check and make sure its not something simple and plugged.
I pulled the vacuum line off the regulator and cycled the pump. Nothing. No gas came out.

I pinched off the return line, and lo and behold it cracked, because gas squirted out everywhere. That tells me the fuel is getting cycled through, right?

BTW, it wouldn't start either way.

It is almost as if it has no spark, but I just checked it again and there is a very good spark. Also, the plugs were wet and smelled of gas..
 

·
Registered
Joined
·
393 Posts
The gas could just be in the line due to siphoning from the tank or even from the rail.If the spring inside is broken it will allow gas through but won,t build enough pressure,thats why I suggested pinching the return line.Just run a new piece of rubber gas line for your return.Your going to have to try to find a ways to tap into the pressure side to see what kind of pressure you have and if it holds.Could still be a bad pump,regulator or even stuck injector allowing it to bleed off pressure.If you have the airbox off and you prime the rail look at the bottom of the injector and make sure they don,t drip or spew gas out after you prime the pump.If you pull the plugs and pour a bit of gas in the cyls does it fire up for a couple seconds?
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #15 ·
Rainman56 said:
The gas could just be in the line due to siphoning from the tank or even from the rail.If the spring inside is broken it will allow gas through but won,t build enough pressure,thats why I suggested pinching the return line.Just run a new piece of rubber gas line for your return.Your going to have to try to find a ways to tap into the pressure side to see what kind of pressure you have and if it holds.Could still be a bad pump,regulator or even stuck injector allowing it to bleed off pressure.If you have the airbox off and you prime the rail look at the bottom of the injector and make sure they don,t drip or spew gas out after you prime the pump.If you pull the plugs and pour a bit of gas in the cyls does it fire up for a couple seconds?
Yup, it starts right up when I dump gas into the cylinder.
Im gonna go replace that line and pull out the airbox and see if I find anything of interest.
 

·
Registered
Joined
·
847 Posts
I don't post much on this forum anymore since I was dissed but since you pm'ed me and specifically asked me to reply here are my thoughts




Ok ..... first things first.

When you turn the key to the start position the fuel pump should run for a few seconds and the ready lamp should come on, it should stay on for about 5 minutes. Actually the length of time it stays on will vary with temperature but you get the idea. Your first post said those things were happening. Good so far. Now when you pull the cord and try to start the engine the ECU should receive a signal from the CDI telling it the engine is turning and the ECU should respond by doing two things. It will begin to cycle the injectors to deliver fuel and it will also cycle the fuel pump again. This fuel pump cycle is a dead giveaway that the computer is receiving the RPM signal and is responding correctly. Each time you pull the cord stop and listen , make sure you hear the pump cycling again. If it is not you need to trace that single black wire from the CDI your mentioned earlier as it is the wire the computer receives the signal from. If the pump is cycling you need to test the fuel pressure. Remove the hose on the fuel rail clutch side and install a tee. Connect the hose , fuel rail and guage to this tee so you can test fuel pressure. Correct pressure is 35-37 psi whenever the fuel pump is running. Once the pump stops the pressure will bleed off , this is normal. If you have low or no pressure check the pickup tube inside the fuel tank as they are quite known to crack and even break off inside the fuel tank causing the pump to suck nothing but air. You may need to replace this line. If you have not done so already replace the two fuel filters also. The low pressure plastic filter installed in the line between the tank and the pump is the same inexpensive filter that the carbureted sleds use. The high pressure steel filter installed in the line after the pump is way overpriced through the Polaris dealer however the fram equivalant FRAM G4777 can be purchased reasonably at any Napa or Walmart or almost any automotive supplier that is handy.


http://www.summitracing.com/parts/FRM-G4777/



Hope this helps
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #17 ·
mrholmquist said:
I don't post much on this forum anymore since I was dissed but since you pm'ed me and specifically asked me to reply here are my thoughts




Ok ..... first things first.

When you turn the key to the start position the fuel pump should run for a few seconds and the ready lamp should come on, it should stay on for about 5 minutes. Actually the length of time it stays on will vary with temperature but you get the idea. Your first post said those things were happening. Good so far. Now when you pull the cord and try to start the engine the ECU should receive a signal from the CDI telling it the engine is turning and the ECU should respond by doing two things. It will begin to cycle the injectors to deliver fuel and it will also cycle the fuel pump again. This fuel pump cycle is a dead giveaway that the computer is receiving the RPM signal and is responding correctly. Each time you pull the cord stop and listen , make sure you hear the pump cycling again. If it is not you need to trace that single black wire from the CDI your mentioned earlier as it is the wire the computer receives the signal from. If the pump is cycling you need to test the fuel pressure. Remove the hose on the fuel rail clutch side and install a tee. Connect the hose , fuel rail and guage to this tee so you can test fuel pressure. Correct pressure is 35-37 psi whenever the fuel pump is running. Once the pump stops the pressure will bleed off , this is normal. If you have low or no pressure check the pickup tube inside the fuel tank as they are quite known to crack and even break off inside the fuel tank causing the pump to suck nothing but air. You may need to replace this line. If you have not done so already replace the two fuel filters also. The low pressure plastic filter installed in the line between the tank and the pump is the same inexpensive filter that the carbureted sleds use. The high pressure steel filter installed in the line after the pump is way overpriced through the Polaris dealer however the fram equivalant FRAM G4777 can be purchased reasonably at any Napa or Walmart or almost any automotive supplier that is handy.


http://www.summitracing.com/parts/FRM-G4777/



Hope this helps
I am very disappointed to hear you have been dissed on this board! Everytime I search in goodle about this sled your username pops up on multiple snowmobile forums. I frequent the Firebird boards, and it is sad to say but there are a ton of internet know-it-alls who will stop at nothing just to argue with someone. I hope this didn't happen to you, but it sounds like it might have.

At any rate, I am very glad you decided to respond to my PM! I am at my wits end with this thing.

Just to clear up any q's, yes the ready light comes on and stays on for a long time cold. Yes the fuel pump cycles for about 5 seconds when I first turn the key all the way to prime. Yes the fuel pump cycles everytime I pull on the rope, but it is for a shorter period. I looked in the tank and the fuel hose is still attached. I also took the cap off and listened, and I can hear gas dumping back into the tank when the fuel pump runs. (The tank was full but I syphoned 6 gallons out to verify the pickup tube and recycling fuel dump)

Ok, this afternoon's tinkering:
Took the airbox out and replaced the return fuel line I punctured. (DOH!)
looked into the throttle bodies and they were dirty, so I cleaned out the gum and such. pulled out the throttle bodies from the motor and looked at the injectors. They had just a tiny bit of fuel hanging from them. Cleaned them off, and energized the fuel pump again. They did not drip. Pulled off the connectors and each injector is at 2.2 ohms. reinstalled everything.
I did find yesterday that the black trigger wire from the CDI box was pinched, so I fixed it with an all weather heat shrink connector.
Also of note, I read that there are two small bolts on the bottom of the motor, facing forward, one for each cylinder, that you can pull out to drain fuel out of when it floods. I pulled those out and a lot of fuel poured out. I waited a bit and reinstalled.

I am not able to test the fuel pressure yet, but I will see what I can come up with as far as a fuel pressure gauge.

I did look at the fuel filters, but since the fuel lines were so old they were hardened and I couldn't remove them easily. I suspect I will have to buy more fuel line and cut the lines off and replace the fuel filters and the lines. It should be done anyways.

So, I guess I have to figure out how to make a fuel pressure guage hook up and then report back.

Again, I thank you mrholmquist for comin on over to my thread and helping me out!

~Cody

EDIT: have the part number for the low pressure fuel filter? Can I get that at a parts store too or only snowmobile shop or dennis kirk? Thanks.
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #18 ·
like would this filter work? Just any filter with 5/16 inlet outlets for the low pressure side correct?
http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=180206&store=&catId=&productId=p180206&leafCatId=&mmyId=
 

·
Registered
Joined
·
847 Posts
polarisn1 said:
like would this filter work? Just any filter with 5/16 inlet outlets for the low pressure side correct?
http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=180206&store=&catId=&productId=p180206&leafCatId=&mmyId=

That would probably be fine if not , here is the one the sled calls for
search that part number and you should be able to find it pretty easy:

http://stores.orpsparts.com/-strse-78/FUEL-FILTER/Detail.bok


something like this is what you need to test the fuel pressure:

http://minimopar.knizefamily.net/quickfpg.html
 

·
Registered
Joined
·
121 Posts
Discussion Starter · #20 ·
mrholmquist said:
polarisn1 said:
like would this filter work? Just any filter with 5/16 inlet outlets for the low pressure side correct?
http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=180206&store=&catId=&productId=p180206&leafCatId=&mmyId=

That would probably be fine if not , here is the one the sled calls for
search that part number and you should be able to find it pretty easy:

http://stores.orpsparts.com/-strse-78/FUEL-FILTER/Detail.bok


something like this is what you need to test the fuel pressure:

http://minimopar.knizefamily.net/quickfpg.html
Hmm, that link is for a 1/4" ID line? Isn't mine a 5/16"? the return line is so I cant imagine the feed line being smaller? I tried searching for Fuel filter on Dennis Kirk and it said no matches.

AWESOME! Thanks for the link to the fuel pressure guage!
 
1 - 20 of 85 Posts
Top