I just got back from a two week ridding vacation in northern Calif. It was a hot 100 deg.+day every day.On my last ride after a 10min. hill climb I stopped at the top of a mountain to wait for my buddy.(3-4 min.)When he arrived we motored on but I only got 100ft. or so then brrrrrrr. Ran out of gas after only 26 miles!! No-Way!My pride and joy has left me stranded in the middle of nowhere.It still has fuel but when I stab the starter button there is no noise from the fuel pump.I check all of the fuses and they are all good.What to do now. I am thinking there is an issue with the tip-over sensor and am getting ready to start tearing into everything and then try the starter again,and magically the fuel pump comes on and it starts right up,does not run very well though and after 20 seconds or so dies again,and again no fuel pump noise.I take a few to double check all connections and they are all good. after about 10 minutes of figuring out a rescue route I try again and the fuel pump comes on again and it runs great!!I took a 15 mile fire road route back to the truck with no issues(was afraid of getting stranded on some trail)and that was the end of my ridding.I was wondering if anyone else has experienced the same thing with the fuel pump and poss.causes.I am thinking that the fuel line being so close the head at the quick connect picked up enough radiant heat sitting at the top of the mountain that the fuel boiled in the line and built up enough pressure to prevent the fuel pump from engaging.I hope that's the case (easy fix w/insulation).Any ideas, or experience with the same issue?? thanx
Vapor lock on 2010 390??
- Thread starter flyinbryan
- Start date
Misery loves company! Check out my saga here (mostly on the last pages):
http://ktmtalk.com/index.php?showtopic=393539
It sounds like you may have what I have. I haven't solved it yet. Hopefully we can solve it together.
http://ktmtalk.com/index.php?showtopic=393539
It sounds like you may have what I have. I haven't solved it yet. Hopefully we can solve it together.
I seem to recall a few mentions of the fuel pump coming lose in the tank. Also lose wires/connections to the fuel pump.
Bryan,
The first thing I would do is to pull your tank off and check the fuel pump pre filter for a white colored material clogging it.
There was another guy on here a while back with a very similar problem. There was a batch of 390 tanks, and KTM 690 tanks that were contaminated with some sort of white substance.
If the fuel pump cavitates due to lack of fuel flow it will shut down to keep from destroying itself, and this can be caused by a clogged pre filter screen.
Have a look and let us know.
Dale
The first thing I would do is to pull your tank off and check the fuel pump pre filter for a white colored material clogging it.
There was another guy on here a while back with a very similar problem. There was a batch of 390 tanks, and KTM 690 tanks that were contaminated with some sort of white substance.
If the fuel pump cavitates due to lack of fuel flow it will shut down to keep from destroying itself, and this can be caused by a clogged pre filter screen.
Have a look and let us know.
Dale
I had something similar happen this weekend for the first time. The bike is a 2009 FE570 with about 50 hours. I know for a fact that it doesnt have the white gunk on the fuel filter. I was riding along for about 30 miles and then it just kinda died. No fuel pump noise for 10 minutes, and then it decides to start right up and ride fine for the rest of the day.
Juicifer said:
Sorry I don't know the answer.
When you had no fuel pump noise for 10 minutes, did the starter motor wind the engine over or was that dead too?
EFI light was not flashing any codes?
Sounds dumb, but I have seen a few people post they have had loose battery terminals before on here. Did you check that?
I had electrical power, it cranked over just fine just no fuel pump.I did not start to tear into it,it just sat for 10 min.or so then presto,happy trails again.(although afraid to get into some technical ridding so just went back to the truck).All connections were good and tight so I guess I will have to look into the wite goo on the pre-filter.Will I need a fresh gasket for the assy.mount? I will post results when I get them.
Bryan,
Check out these two threads...........
viewtopic.php?f=1&t=11912
viewtopic.php?f=1&t=12771&p=107274#p107274
Check out these two threads...........
viewtopic.php?f=1&t=11912
viewtopic.php?f=1&t=12771&p=107274#p107274
DaleEO,
Thanks. I was hoping that was my problem. But it sounds like flyinbryan and I may have the same problem. My filters are spotless, yet my bike just refuses to fire when it's hot. It runs perfectly fine, and will run fine forever. However, if I shut it off, it won't restart when hot. It cranks with full power, but it won't ignite. Then after 15-20 minutes of sitting, it fires up with one touch of the start button and runs perfectly. I didn't think of listening to the fuel pump, but I think that's exactly my problem. I think during those times when it won't fire, my fuel pump is not getting power. I have the newest ECU mapping. I checked all the wiring and connections as carefully as I could and can find nothing wrong. I've removed and reinstalled all my fuses but that didn't help either. I'm really convinced it's a bad fuel pump relay, but Husaberg says, "We have never had one go bad." I don't think it is likely that a fuel pump can switch on and off by itself, but I know a relay can.
Thanks. I was hoping that was my problem. But it sounds like flyinbryan and I may have the same problem. My filters are spotless, yet my bike just refuses to fire when it's hot. It runs perfectly fine, and will run fine forever. However, if I shut it off, it won't restart when hot. It cranks with full power, but it won't ignite. Then after 15-20 minutes of sitting, it fires up with one touch of the start button and runs perfectly. I didn't think of listening to the fuel pump, but I think that's exactly my problem. I think during those times when it won't fire, my fuel pump is not getting power. I have the newest ECU mapping. I checked all the wiring and connections as carefully as I could and can find nothing wrong. I've removed and reinstalled all my fuses but that didn't help either. I'm really convinced it's a bad fuel pump relay, but Husaberg says, "We have never had one go bad." I don't think it is likely that a fuel pump can switch on and off by itself, but I know a relay can.
JohnnyQuest said:
Hi JonnyQuest,
There is no Fuel Pump Relay. The EFI Computer turns the Fuel pump on and off. It may have a little internal relay inside the EFI Computer or just a Mosfet Transistor that switches the Fuel Pump on and off. The green line below shows the path +12 volts takes. The red circle shows where there may be a relay inside the EFI Computer.
Have you checked your earth connection from the Fuel Pump Connector, it is the brown wire and it must go back to the frame somewhere. Not sure where as I have never had my tank off.
Sounds like you have the "Hot Start" issue that has popped up a few times on this forum. I am still confused on what the "Hot Start" problem is.
Davo said:
Definitely not the battery terminals, the engine still cranked hard and all electrical worked. I'm not sure about the codes, but it seemed like the EFI light never came all at all until it finally started again.
How do I check for codes?
If the fuel pump isn't getting power at some time, it would seem to me to be an easy thing to check; carry a small voltmeter with you and when the bike won't start check the voltage to the fuel pump as per the circuit diagram Davo posted.
Davo,
I’d say that the best way to rule out a particular part as being the problem is to determine that it doesn’t exist!
The “thing” sitting on top of the tank is what I thought was the relay. However, according to page 19 of the chassis parts manual it’s a “Pressure Regulator CPL” (part 4). Do you know how that works? I didn’t check the connector (inside the tank) between the pressure regulator and the fuel pump. I’ll examine that connector. I’ll also check the blue/grey back to the computer and the brown to ground as you suggest. Those two wires connect to the pressure regulator and then go to the pump inside the tank. Thanks a lot! I’m getting optimistic I will find the culprit!
I’d say that the best way to rule out a particular part as being the problem is to determine that it doesn’t exist!
The “thing” sitting on top of the tank is what I thought was the relay. However, according to page 19 of the chassis parts manual it’s a “Pressure Regulator CPL” (part 4). Do you know how that works? I didn’t check the connector (inside the tank) between the pressure regulator and the fuel pump. I’ll examine that connector. I’ll also check the blue/grey back to the computer and the brown to ground as you suggest. Those two wires connect to the pressure regulator and then go to the pump inside the tank. Thanks a lot! I’m getting optimistic I will find the culprit!Here are some further suggestions:
1 Check all battery and relay and round bolts
2 Check the wire harness in particular near the shock reservoir and look at the power leads going to the pressure regulator because I have seen where people put the tank back on the bike they do not pay attention and the lead will melt against the mid pipe and short out but when it cools the sheathing will break the short and it will run fine.
3 Everyone claims they have the newest map – they have to have the dealer make sure of the part number for the map it might not be the “latest version” anymore. There is a current version of the comp map that helps hot starting considerably. The original one you had to crack the throttle ever so slightly when the bike was really hot.
4 Remove the in-line check valve in the vent line coming out of the gas cap. The one in the cap is sufficient by itself.
5 Look into an after market muffler. Exhaust does more than just make more HP it lets the bike run way cooler due to less restriction.
6 Finally let the dealer do their job. They have diagnostic tools that can save a lot of wasted money just changing parts and driving all over.
1 Check all battery and relay and round bolts
2 Check the wire harness in particular near the shock reservoir and look at the power leads going to the pressure regulator because I have seen where people put the tank back on the bike they do not pay attention and the lead will melt against the mid pipe and short out but when it cools the sheathing will break the short and it will run fine.
3 Everyone claims they have the newest map – they have to have the dealer make sure of the part number for the map it might not be the “latest version” anymore. There is a current version of the comp map that helps hot starting considerably. The original one you had to crack the throttle ever so slightly when the bike was really hot.
4 Remove the in-line check valve in the vent line coming out of the gas cap. The one in the cap is sufficient by itself.
5 Look into an after market muffler. Exhaust does more than just make more HP it lets the bike run way cooler due to less restriction.
6 Finally let the dealer do their job. They have diagnostic tools that can save a lot of wasted money just changing parts and driving all over.
Thanx for all the help and suggestions everyone, I am going to look into the "white substance" this evening.I have already checked and rechecked the wiring and connections and routing issues before hand as I was aware of those from reading posts here for sometime.As per my original diagnosis,nobody seems to have a comment.Could it not be as simple as excessive heat build up radiating from the cylinder head when not running after hammering on it during a long hill climb? Does the fuel pump run momentarily to build up pressure then go silent? I would think that the location of the fuel line by the quick connect is extremely close to the head and could build up enough pressure(from the radiant heat) to prevent the fuel pump from engaging.Thereby it may partially vaporize the fuel in the line so as to not allowing the bike to run until it cools down just enough to allow solid fuel at the throttle body.It may also be affecting the pressure regulator if I can find it.I am kind of stuck on the heat thing because that was the only time it has happened to me.100 deg temps and pushing the bike pretty hard then I shut down for 5min or so,then no fuel pressure.
flyinbryan said:
Fuel Pump runs momentarily to build up pressure then EFI Computer turns Fuel Pump off if the motor has not started. The Pressure stays in the Fuel line for some time (more than a few minutes at least, maybe longer).
If the Fuel line is heated up and builds up pressure the Pressure Regulator in the Fuel Tank will release that pressure back into the tank. That is the regulators job to maintain that constant fuel pressure as best it can do with the Injector opening and closing all the time for different lengths of time dependant on the engines requirement for fuel. The pump is dumb it is designed to just pump at a pressure higher than the regulator regulates.flyinbryan said:
There are a few questions above I might have a crack at answering shortly. Dale is spot on with trying to start it with the throttle cracked open a bit.
I wonder if the basics are there, fuel and spark. Anyone tried checking spark and looking at the plug to see if it is wet or dry when they wont start?
Trust me, all the basics covered,throttle poss.ect.ect.Just not getting the fuel pump to run for a few minutes. Like I said it has only happened once.But that's enough to make me a little nervous until I can solve it,as I like to go off the beating path and I don't like the idea of walking out of nowhere.And yes,I do have what is said to be the "latest map" installed 1 month ago,and it does help with hot starting and seems to be just a touch snappier all around.
flyinbryan said:
I hear where you are coming from being nervous getting stuck off the beaten track. Either way if you fix it I hope you post the answer back on UHE because I bet there will be another person like you in a month or two with same problem.
flyinbryan said:
The pressure regulator is at the top of the tank, where the fuel line comes out of the tank, it's mounted on the back side of that plate. Like most FI systems, the fuel constantly circulates within the tank as the excess fuel pressure is bled off at the regulator and a line returns the fuel to the fuel pump holder at the bottom of the tank.
Usually once you punch the starter button, the FI light comes on momentarily and you can hear the fuel pump run for a few seconds and then it shuts off. I take it the FI light did not come on when you were having drama's?
The reason this happens is b/c there is the computer via the crank position sensor or trigger causes the fuel pump switch in the ECU to close and run the fuel pump. I know that you have said that you have checked all connections, but, have you checked to make sure the the ECU plug is firmly plugged into the ECU unit? There was a fellow a while back that was having a similar problem, and found that this plug was not secure. Maybe try unplugging it and plugging it back in.
An intermittent problem like this sounds electrical in nature.
Further, as I mentioned before, there is a map that was developed to help with hot start issues. Folks were having to hold the throttle open a little bit to get it to start. Did you try manipulating the throttle when you were trying to start it when it wouldn't?
IMHO you need to check with your dealer and make sure that the latest map was installed in your bike, the hot start issue one.
Hey Dale,
There was 1 question above that I think you can answer but maybe you missed reading it, do you need a new gasket when you pull the Fuel Pump out?:
There was 1 question above that I think you can answer but maybe you missed reading it, do you need a new gasket when you pull the Fuel Pump out?:
flyinbryan said:
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