Throttle problem

I am thinking about buying some e-bay coils. I was hoping that in the last two years someone else may have had the same problems.
 
Simmons1 said:
I would be game to replace the coils at my expense to avoid having the bike in the shop forever, but the fuel pump assembly is another story.

Thanks in advance!
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I've got a spare set of coils that I'd be willing to let you use for as long as you need to diagnose your problem. Came off of a bike being parted out on eBay. I believe the bike had about 4K miles on the odometer. All I ask is that you pay for the shipping there and back.

USPS priority mail might be the cheapest. My zip code is 53022.
 
Scooter said:
I've got a spare set of coils that I'd be willing to let you use for as long as you need to diagnose your problem. Came off of a bike being parted out on eBay. I believe the bike had about 4K miles on the odometer. All I ask is that you pay for the shipping there and back.

USPS priority mail might be the cheapest. My zip code is 53022.
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Thanks for the offer. I just bought a set on e-bay. Since the problem is weather dependent I would feel guilty not knowing how long I may have your parts.

I'll post back here after I have tried the coil change.
 
It wouldn't bother me. They have been sitting on my shelf for about a year now anyway. I hope the new coils resolve your issue.
 
July 16 UPDATE

Coils are in.:(

Looks to be the fuel pump right now. I have one on order that should be here in a week or so.
 
July 27 Update

Installed the new fuel pump tonight. It was silver instead of gold colored and seemed to sound quieter.

It is supposed to get good and hot again by the weekend for testing.
 
August 7 Update

We have a winner!

It was the fuel pump causing the problems. The new one has been well tested this week and the bike never missed a beat.

I am a happy camper.
 
Bumping. My bike has the same symptoms; wicked surging when the engine is heat-soaked. Runs relatively ok at full throttle, but back off the throttle, and it chokes.

Pipes are wrapped, prev owner installed a TC-FPR. Occurs with full or low fuel level. Occurred this summer in 110 deg., and now this weekend at 75 deg outdoor temp.
 
If you recall, my bike offered me an "E"-ticket ride one afternoon when coming home from work. Halfway through the commute, the bike started bucking/surging/stalling in a very bad way. I ran a full tank of Chevron and a full bottle of STP Fuel Injector Cleaner through; that was approximately 2500 miles ago, and she's still running strong.

Going to the dealer with these types of issues is pointless, as I always get the same story: "We can't seem to reproduce the symptoms Sir." How is it that Man can put himself on the Moon and go to the bottom of the sea, but for some reason he can't figure out why a relatively simple V-4 motor is misbehaving?

Cheers!
Bill
 
Seems it is a combination of heat and fuel pump to me..... reason the dealer can't find it is they don't run it fast enough, long enough or hot enough....

A couple of hours of running hard, followed by a short stop, allows the heat build up in the tank...... then you get issues....

Maybe...... just maybe, putting a lower threshold on the cooling fan would help on this, plus a fan run on using a timer if the engine is hot when shut down?

I used to get issues a few years back with a car that did similar things, dealer couldn't fix it, said it was the fuel, my old CX500 used to do it on really hot days, (yes we do get some), it turned out to be pre-atomisation of the fuel due to excess heat around the engine.
The car was cured by fitting a heat shield to erm... the fuel pump and filter.......

Just an idea....
 
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Wow, I have to thank STranger for pointing me to this thread. I have this exact problem. On hot days I've been experiencing hesitation followed by surging then stalling. If I hold the throttle steady the RPMs bounce around, giving the appearance of a vacuum leak. I have to wait awhile, then I can start her up again. The problem will repeat until I get into cooler weather (seems to be around 80 - 85 degrees or so).

This past Saturday we had the bike apart at the campground (Lee Vining RTE). The vacuum lines under the airbox looked fine. I took the 5 way T out and inspected it. Everything looked fine. At that point I figured it must be the fuel pump, MAP sensor, throttle position sensor or a combination of those things.

I've attached a video of my bike misbehaving. When the RPMs are bouncing around, I'm holding the throttle steady.

http://www.youtube.com/watch?v=xvPmwFkticI
 
I had the same behaviour but nowhere near as bad as that video shows. I replaced the fuel pump and everything has been fine for 7K. Bike seems to run better, 10% better MPG and a bit more heat.

Just one more data point.

Andy
 
SHAZZAM!!!

I am the EXACT TWIN to this thread!!!

Mine blew the Air Temp Sensor code... I replaced it,,, and it still is the same...

Go ahead and laugh,,, but,,,

To get home from the West coast I noticed that the tank temp had as much to do with the way mine ran as the Air temp did... I would take my glove off running down the road and as long as the tank was cool,,, it ran fine...

As soon as the tank got hot,,, the bike ran bad... I thought that since the air sensor sat right under the fuel tank the heat from the fuel tank was cooking the sensor...

So,,, get ready to laugh...

I was buying bags of ice and placing them on my fuel tank going down the road!!! :crackup You just have to witness a car following you on a 107 degree day running with the windshield wipers,,, with not a cload in the sky!!! :nanner1::crackup:D;)

So,,, you see,,, this is looking to be a fuel pump problem with me i think...

The ice made the fuel cold... Without the ice the tank got hot in 30 - 60 miles and ran bad...

With the ice on my tank the bike would get 51 mpb (((51 miles per bag))) :rolleyes: before melting!!! :crackup After that,,, the tank would heat up around 80 - 100 miles and it would run bad again...
 
Simmons1 said:
My bike has run perfect since I put in the new fuel pump last August 15K miles ago.
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Great to hear and thanks for the update!!! That will help me a lot!!! :bow1:

I have been told that running your tank down to near empty makes the pump run really hot and might be the reason for failure...

Hi Everyone,,, my name is ACL,,, and I run almost out,,, 300 mile tanks,,, or out of gas often...:rolleyes:
 
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