Hard start and rough idle

[dzimbric]

I have a '04 1150 Rt (twinspark) with +38,000 miles. It started to idle rough and become a liitle hard to start about 35,000 miles. By hard to start I mean it catches after a couple of seconds on the starter then dies. It catches and idles on the second or third or fourth try. I have to kick the idle up a little when it's cold by using the throttlemeister.

Manic mechanic and I replaced the plugs and alternator belt at 37K and adjusted the throttle bodies. It seemed to run better but it is still hard to start.

I may not have had the bike fully warmed up when we adjusted the right side carb(slave) to match the left.

I also added the sparky pegs at the national. You have to remove and discard the clip that connects the high voltage lead to the end of the ignition tube. The plugs stays but the clip helps secure the plug. The plug has a o'ring which helps keep it seated and dry. After installation of the sparky peg, the peg appears to keep the lead from coming off the ignition tube.

No fault codes were stored in the computer.


Questions:
1. How does the dealer check/set the throttlebodies and is it any better than the Twinmax?

2. Are there additonal adjustments that can be done on the moronic fuel injeciton?

3. Do I need to leave this to the dealer and his equipment?

4. What else should I check? Since my local dealer went out of business I am trying hard to becvome independent of the dealers and do as much as I can myself.:dunno

5. Can this be an ignition problem instead of a fuel injeciton problem and how do I diagnose the difference?

[cat0020]

Do you use the fast idle lever on until at least the first bar shows up on the temperature guage? :confused:

Usually I try and have the throttle sync done after at least 5-10 miles of riding.

no idea what "sparky pegs" are...:dunno

With the help of my local BMW club members, I've stopped going to the dealers for services since the bike turned 12000 miles, now at 25800 miles, I'll just go back to the dealers for parts.

[jdiaz]

I'm pretty sure the fast idle cable has stretched and is not pulling the throttles open as much. There should be a freeplay spec up at the handlebar for that.

[kbasa]

When was the last time you had a valve adjustment and throttle body synch?

[jdiaz]

Originally posted by KBasa
When was the last time you had a valve adjustment and throttle body synch?
~1000 miles?

[username]

i had (sorta have) this same problem. i took it back in, they redid the throttle bodies, and the problem was lessened. (they may have done something else...the bad part about not doing it myself. *some* of us are able to keep our bikes under warranty for a little while. ;) )

i still get finicky starts. mine never starts on the first try. i decided to really care about the starting if it blows a cloud of blue smoke. as long as it isnt doing that, im ok. ymmv.

[kbasa]

We had a similar problem with our RS and it turned out the TPS was pooched.

[dzimbric]

I also posted this on the bmwsporttouring.com forum and one subscriber mentioned he had a faulty plug upper plug coil that was only diagnosed after he persuaded someone else to swap coils with him. The problem then followed the coils to the other bike.

Kbasa the valves were checked (no adjustment required) and the throttlebodies synced at 37K. I just turned 39K last night.

The fast idle cable and the throttle cables in general may have stretched slightly. This would explain why it is idling around 900-1000 rpm. The fast idle cable still has an effect becaquse when I lift it rasies the idle to about 1200 rpm. I think this is low and the idle is normally set arouind 1100-1200 with the fast idle around 1500.

The best plan I can come up with right now is to recheck the throttle body sinc with the motor warmed up to five bars. I think I skimmed this step when I originally adjusted the throttlebodies. John mentioned this as important on his article.

It caused an improvement originally and I may just be idling low now. The next step is to find someone with a twinspark that may be willing to swap upper ignition coils to see if they inherit the problem.


Oh and the sparky pegs are highway pegs that mount on the twinspark head. Installation requires you discard the clip that holds the ignition wire in the socket. The function is performed by the sparky peg after it is installed. An o-ring also helps keep the plug properly seated and dry.

I don't think it is a poor wire/plug insertion, just rode in a heavy rain and it had no negative effect on the motor except it is cleaner.

Thanks for the help.

[dzimbric]

Originally posted by KBasa
We had a similar problem with our RS and it turned out the TPS was pooched.

Dave
Throttle position sensor?

Wouldn't that cause it to happen all of the time and not when it is just cold?

[kbasa]

Hmmm. Didn't realize it was a cold start and idle issue.

[manicmechanic]

Dan wanted to learn how to do some of the maintenance items, so I showed him how to check/set the valves, do the belt, sync the TB's. Valves were fine, TB's were off just a little at idle, fine off-idle. Didn't do TPI check. Blew out the K&N air filter. What else to do? I regret not checking the "choke"/fast idle cable. As Dan said, it does start easier, but needs to crank for 3-4 revs before starting. Ideas?

[username]

i didn't really think i had a problem, but to be clear...

when cold, you other oilhead enthusiasts have bikes that you press the starter and 'varooom' the thing starts up almost instantly?

im not trying to hijack the thread, but i want to get a good definition of how the bike is supposed to behave when cold.

[jdiaz]

Early (as in the first ones) Oilheads used to require tons of cranking to start. BMW said it was to build up oil pressure before allowing the engine to start, but mysteriously, the second rev of the beta bikes lit off after 1-2 cranks. There was a change in the Motronic.

I personally wouldn't worry about 3-4 cranks to start. If you have to hit the starter button multiple times, or the bike won't hold an idle at the low fast-idle setting, then I would start checking other things.

[breyfogle]

My 94 Beta never starts on the first press of the starter button when cold. I can crank all day, still nothing. But, after one quick short press and release, the second press almost always starts the bike right up. With a warm engine, it starts first press every time.

WRT the fast idle cam, at the first detent and a cold engine initially results in about 1200RPM but this climbs within 15-30 seconds to over 2000 RPM.

Normal warm idle with fast idle "off" is about 1000-1100 RPM, any lower and the bike tends to skip a beat every now and then as if it was trying to stall (the flywheel generally keeps is running).

[dzimbric]

Thanks to everyone for the suggestions.

I picked up a fuel filter today. John at Nicks BMW said it should have been changed around 24K. Last night I was playing with it, turning on the fuel pump and back off as one member suggested and it still didn't fire right up. Then later I went out to get something to eat and it fired as soon as I pressed the button on a cold engine. I don't know if this is related to playing with fuel pump or not.

The fuel pump system works by drawing fuel throught the filter from the tank, once it reaches a preset pressure the pump shuts down. I can hear this happen by switching the ignition on and off. If the filter was plugged I should not hear the pump shut off after it reaches pressure. But then it fired right up, and didn't bog when I went to leave.:dunno

[dzimbric]

We replaced the fuel filter today and it made a noticable difference. Double checked the throttle bodies and the valves. No adjustment required.

Well all I have to do now is pack the bike and head off to Dothan, Al, Florida City, FL, Rebel Yell II in Suches, GA and back to IN. by 10/10.:dunno