BMW K1200, K1300, and K1600 Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
478 Posts
Discussion Starter · #1 ·
Hi All,

Just got back from a trip to Florida with my bud Rich_MC.....

On the way down there, we were getting to our destination and my bike started to surge really bad at idle (in neutral or first). I had about 180 miles on the tank - so I figured I ran the tank dry.

Luckily, we were right by a gas station. I filled up the tank with about 4.7 gallons of gas. It seems to me this is about right for being "empty", but still having the fuel pump wet.

As I started the bike up again, it idled very poorly and you could watch the RPMs surge up and down. It even stalled a few times.

We got to our destination a few blocks away and it was still acting up. We decided to let it sit overnight and try it out in the morning.

In the morning, it was fine - started right up no problem. We concluded that it musta just been low on gas and the injectors were a bit clogged up from sucking in the gas from the bottom of the tank.

I rode around Florida for a few days - mainly at city traffic speed (ie stop and go). No problems at all....

When we left to come home, I ran low on fuel again (my fuel light came on at around 157 miles - which is fairly typical when I'm loaded down, etc.). This time, when we pulled off the highway 2 miles down the road, my bike started to surge like a bucking bronco again. I filled up, but this time with only 4.3 gallons of fuel.

This amount of fuel (4.3 gallons) seems fairly typical for me on a fillup when I hit the fuel light. So needless to say, I was concerned when I let the bike idle, and the RPMs surged around and it even stalled twice......

I've noticed a few things here:
- the bike runs fine at speed (and in the upper RPMs)
- this does NOT occur all the time - very sporadic
- this only seems to occur when the RPMs are low

I've added Techron and used Chevron gas a few tiems to get the fuel injector cleaner into the system to see if that will help any. I'm wondering if something else could be wrong here becuase it seems to me to be more of a fuel delivery problem than an actual running out of gas problem....

Thanks!
alow
 

·
Registered
Joined
·
312 Posts
ECU Replaced?

I had similiar surging problems plus really rough idle at start up.
Surging would happen at idle no matter how much gas was in the tank tho.
Got the new ECU and problems disappeared.
That problem seems to manifest itself in a lot of ways.
Might want to check that out if you have not already.....
 

·
Registered
Joined
·
52 Posts
I would make sure that my gas tank vent hose was not clogged or crimped.

Did you notice a lot of pressue when you opened the fuel door to gas up?

Next time it happens, open the fuel door to relieve pressure and see if it is still doing it. In this case it would be nice to have your spare key hand to see if it clears it up while it is still running. Having to shut down and restart might allow the backpressure to escape anyway.

Just a thought.

Randy
 

·
Registered
Joined
·
478 Posts
Discussion Starter · #4 ·
Just a quick note - I did have the ECU replaced earlier this year (I actually had the cold start problem).

I did open the fuel door after shutting off the bike, didn't notice any pressure, but I may try the 2 key trick next time I experience it.

I will also check the fuel vent hoses to see if they got crimped or something - I don't think they did - but it couldn't hurt.

Worse comes to worse, I'll have the dealer check it out when I take it in for the free oil change I have coming up....

alow
 

·
Registered
Joined
·
131 Posts
How long's it been since the fuel filter was changed? My '03 did that until the 24,000 service. Fuel filter looked like it had seen better days.
 

·
Registered
Joined
·
23 Posts
Surging

My BMW car has done something simlilar twice. Both times following a bad start cycle. Once from a low battery and once from the key sliping in my hand. Did a lot of the normal fixes but nothing worked. Finally I disconnected the battery leads and held them together to completely drain any residual voltage. When I reconnected the battery, it ran perfectly.

I think that the computer stores some bad information when the voltage is unsteady and you need to completely ground the power to make the computer reset to the factory defaults. Give it a try, it is easy and cheap compaired to the other options.
 

·
Registered
Joined
·
41 Posts
TPS, canister

Alow, Have the TPS checked, perform a sweep test. Check the canister connections and look for an overloaded condition. When was the last time the plugs were pulled?
 
1 - 8 of 8 Posts
Top