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Are the TBs To Blame or Not?


Claudio

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I've read all the posts on TB rebuild and am not sure if my bike is in need of it so I thought I would reach out to the wisdom of the group.

 

Bike: 2003 R1150RT, 120,000 kms on the Odometer

 

Recent symptoms that were corrected with new stick and secondary coils + new secondary plug wires included weak start, sluggish performance, almost stalling after start until running at temp (bogging down).

 

I had the TB balanced and cleaned prior to replacing the secondary coil myself but not since then. The tech had been messing with idle speed and TB tuning (I think) to compensate for bad coils.

 

The last minor symptoms I have left is:

1. Slightly rougher idle with a bit of random fluctuation of the RPM (+/- 100 RPM) from idle at 1,100 RPM.

2. When I apply the throttle just enough to remove the free play from the cable, I hear a "nice" loud clapping sound that I presume are the TBs. This becomes apparent at the moment the free-play is removed. The "clapping" disappears at slightly higher RPMs (~1500+).

 

Possibly Unrelated

3. Exhaust smells rich/gas when first started.

4. When I put my bike away after a hot ride, it fills the garage with a strong gas scent. No signs of a leak in the quick disconnects.

 

I suspect the TBS may be "leaky" (air passing) and worn (rattle) but have no experience messing with them so I may be way off.

 

Any diagnosis wisdom would be appreciated. I am pretty sure I could handle the TB rebuild myself but my tuning/balancing skills are non-existent so I'd take it in for that.

 

Edited by Claudio
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Depending on how full my tank is after a heat soak in the garage I also get a fuel smell. Not sure if the American bikes with the canister have the same result.

 

One upgrade I did on my 03 was to put the stick coils on a separate circuit as the factory did with some late 03's and all the 04's. This mod takes the stick coils out of the key switch circuit and gives them clean power on their own circuit.

 

Along with the exif to alter the fuel mapping the coil circuit made the biggest improvements in my bike and like you I had put in new stick coils.

 

I haven't had the need to repair the tb's so will let others advise on that.

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Depending on how full my tank is after a heat soak in the garage I also get a fuel smell. Not sure if the American bikes with the canister have the same result.

 

I too have noticed a correlation to fuel level and smell level. It seems to be stronger the emptier the tank is. Sometimes it is soo strong I worry about sparking up fumes in the enclosed garage.

 

 

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Morning Claudio]

 

Bike: 2003 R1150RT, 120,000 kms on the Odometer

 

Recent symptoms that were corrected with new stick and secondary coils + new secondary plug wires included weak start, sluggish performance, almost stalling after start until running at temp (bogging down).--OK, we will try o address this problem.

 

I had the TB balanced and cleaned prior to replacing the secondary coil myself but not since then. The tech had been messing with idle speed and TB tuning (I think) to compensate for bad coils.--The coils shouldn't effect the TB balance as the TB balance is based on intake vacuum not cylinder power.

 

The last minor symptoms I have left is:

 

1. Slightly rougher idle with a bit of random fluctuation of the RPM (+/- 100 RPM) from idle at 1,100 RPM.--Could be normal, could be a slightly dripping fuel injector, could be the wrong or missing CCP in the fuse box, could be the o2 sensor not responding correctly (especially at you mileage), could be ????

 

2. When I apply the throttle just enough to remove the free play from the cable, I hear a "nice" loud clapping sound that I presume are the TBs. This becomes apparent at the moment the free-play is removed. The "clapping" disappears at slightly higher RPMs (~1500+).--This is pretty normal as you have lifted the TB cams just slightly off the idle stop screws so the harsh Boxer intake pulses deflect the throttle plates just enough to cause the TB cams to rattle on the stop screws.

 

Possibly Unrelated

 

3. Exhaust smells rich/gas when first started.--This might also be normal as the fueling does run rich at cold start up. Or if excessive then you could have a dripping fuel injector when parked, or your CCP is incorrect or missing, or your fuel tank venting is restricted & over pressurizing the fuel tank when parked, or you are still running winter gasoline in warm weather, or ?????

 

4. When I put my bike away after a hot ride, it fills the garage with a strong gas scent. No signs of a leak in the quick disconnects.-- Again possibly a dripping fuel injector, or the fuel tank venting is not working correctly, or you have a slight fuel leak but the fuel is evaporating before it can puddle, or one of the in-tank small hoses is seeping fuel into the water drain hose or tank vent hose (both of those hoses pass through the fuel in the tank). Or you have a leaking fuel tank gas cap seal (I have seen a few of these over the years)

 

I suspect the TBS may be "leaky" (air passing) and worn (rattle) but have no experience messing with them so I may be way off.--As a rule the TB shafts & bushing do get a bit of wear as bike's mileage gets higher but the unless excessive it doesn't cause any issues. Even if the TB's do leak a little air at closed-throttle idle about all that does is raise the idle RPM's a little. Above idle the throttle plates are open anyhow so a little TB shaft/bushing wear usually causes no problems while riding the bike.

 

Any diagnosis wisdom would be appreciated. I am pretty sure I could handle the TB rebuild myself but my tuning/balancing skills are non-existent so I'd take it in for that.-- Lets start with the CCP, does your bike still have the correct CCP in the fuse box (usually pink in color)?

 

Does your bike have an evap can hanging from the RH rear of the frame (looks like a black can with hoses going to it)?

 

Have you put fresh gasoline in in since the weather warmed up?

 

Any sign of a wooshing sound when you open the fuel tank cap after riding the bike for a while? Or does the gas cap appear stuck shut when trying to open it after riding the bike for while?

 

Any signs of moisture or smell coming from the small hoses that exit behind the R/H riders foot peg?

 

Have you done a new TPS re-learn to see if that helps?

 

Does your bike still have the original o2 sensor (at your mileage that might be getting lazy, poisoned, or dead).

 

You have a LOT going on in one post here so we might have to go after each thing one at a time in separate threads.

 

 

 

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Thank you for taking such care/time in your response. Greatly appreciated. I'll look into a few items that I haven't yet from your advice and report back.

 

 

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Claudio,

 

IF you are having an issue with the injectors, per what DirtRider describes above, you might consider 1) having your injectors cleaned and flow tested, or 2) replacing your injectors with a pair of tested and matched EV14 injectors (R1200GS type).

 

Contact Keith Gibbons at Injector-Rehab, keith@injector-rehab.com.

 

I have done this with my '99 R1100S and RT and am very pleased with the results. He has the adapters, new and refurb injectors, and provides test reports on all injectors.

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Ok. Here is my update.

 

I am going to not focus on the TBs based on DRT's synopsis but there is merit in the other possibilities.

 

Some updates:

O2 Sensor - replaced within last 3 years by yours truly.

Fuel Lines / Fuel Pump Plate Gasket - I inspected last year along with new seals when I serviced the fuel filter. Everything looked normal.

Evap Canister - Not on my bike

CCP - Original still in place, never touched it (I am the second owner of the bike and have had it since 14,000 kms.

Gas - on my second tank since winter.

Tank Pressure - no signs of abnormal pressure.

Smell Location - Nothing notable from the R/H riders foot peg, smell seems to be concentrated over the tank/general area above the engine.

I *think* my fuel mileage is down/poor (not sure)

 

Next Steps I think I am going to try:

TPS Relearn - Will try it this weekend.

- Measure fuel efficiency on next opportunity (highway ride).

- Inspect/replace tank/cap seal (cheap and easy).

- Replacing the injectors outright seems like a reasonable idea given that its fairly straightforward and may resolve the issue without agonizing troubleshooting.

 

Injector

- I'll check with the suggested source (above)...thanks!

- Anyone have experience with the injectors from www.euromotoelectrics.com (I've purchased other items from them and been very happy w quality and order process)?

 

 

Edited by Claudio
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Ok. Here is my update.

 

Morning Claudio

 

 

O2 Sensor - replaced within last 3 years by yours truly.--Was the o2 replaced with a BMW o2 or aftermarket? If a replaced with an aftermarket you didn't solder the connections did you? (soldering o2 sensor wires can block proper reference air entry)

 

Fuel Lines / Fuel Pump Plate Gasket - I inspected last year along with new seals when I serviced the fuel filter. Everything looked normal. Those in-tank hoses can LOOK GOOD one minute then be split the next ride. They usually fail from the inside out.

 

 

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Ok. Here is my update.

 

Morning Claudio

 

 

O2 Sensor - replaced within last 3 years by yours truly.--Was the o2 replaced with a BMW o2 or aftermarket? If a replaced with an aftermarket you didn't solder the connections did you? (soldering o2 sensor wires can block proper reference air entry)

I believe it was this one from Bosch. No soldering, came ready to plug and play: http://www.euromotoelectrics.com/product-p/o2-022.htm

 

Fuel Lines / Fuel Pump Plate Gasket - I inspected last year along with new seals when I serviced the fuel filter. Everything looked normal. Those in-tank hoses can LOOK GOOD one minute then be split the next ride. They usually fail from the inside out.

I'll take the wise advice and re-inspect.

Edited by Claudio
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Fuel Lines / Fuel Pump Plate Gasket - I inspected last year along with new seals when I serviced the fuel filter. Everything looked normal. Those in-tank hoses can LOOK GOOD one minute then be split the next ride. They usually fail from the inside out.

 

I'll take the wise advice and re-inspect.

 

Evening Claudio

 

You might not have to pull it apart & re-inspect. You can probably do a warm engine/warm fuel return-flow-test.

 

If you have good fuel return fuel flowing with warm in-tank fuel then your hoses are probably OK.

 

 

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You might not have to pull it apart & re-inspect. You can probably do a warm engine/warm fuel return-flow-test.

 

If you have good fuel return fuel flowing with warm in-tank fuel then your hoses are probably OK.

 

I've never done one of those tests but I was able to find general instructions from one of your other posts.

 

I have a spare quick disconnect (old plastic one) I can use for the test. So basically warm things up, connect to the return line and turn on the ignition (don't start the bike). The system should pressurize and I should get moderate / significant flow on the return?

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You might not have to pull it apart & re-inspect. You can probably do a warm engine/warm fuel return-flow-test.

 

If you have good fuel return fuel flowing with warm in-tank fuel then your hoses are probably OK.

 

I've never done one of those tests but I was able to find general instructions from one of your other posts.

 

I have a spare quick disconnect (old plastic one) I can use for the test. So basically warm things up, connect to the return line and turn on the ignition (don't start the bike). The system should pressurize and I should get moderate / significant flow on the return?

 

Morning Claudio

 

Yes, that is basically the idea.

 

A couple of points--

 

Be sure to connect to the return hose coming from the rear & plug off the return hose coming from the front (the check valve in the front disconnect should effectively close off the front hose)

 

At key-on you will only get about 2 seconds of fuel flow (SO) you will either need to run the engine or jump the fuel pump relay to get full time fuel return flow.

 

A pencil sized stream of fuel is usually a good guide but (Roger 04 rt) actually figured the return flow should be around 2 liters per minute.

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Flow is good. TPS reset done.

 

I think (process of elimination) I have a leaky injector. Two replacements on order. Will report back. Appreciate the fantastic insight and knowledge.

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One last question.

 

Once I replace the injectors, is a TB balance required/a good idea?

 

Morning Claudio

 

No & possibly--How's that for a decisive answer.

 

Basically the TB balance is an air flow thing not a fueling or combustion thing so replacing injectors shouldn't effect it.

 

BUT-- you will be working on & around the TB's so something could be bumped, moved, or a cable disturbed so a quick

TB balance check sure wouldn't hurt.

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Good points DR. But if the injectors spray a couple percent more fuel, idle speed could go up.

 

Afternoon Roger

 

Good point but you would think the o2 sensor should pull that couple percent more fuel back out at idle to keep the idle fueling compliant.

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  • 4 weeks later...

Just an update on the final remedy for all that ailed the bike.

 

1. After conducting a fuel flow (return) test I focused on the TB seals, o-rings, and injectors.

2. This probability of a leaky injector seemed likely given the symptoms.

 

This past weekend, I replaced both injectors, did a basic cleaning of the TBs (on the bike) and replaced the o-rings on the TB air intake. As I had previously replaced a bad secondary coil, I also gave the bike a new set of plugs.

 

The RT now starts and runs better than it has in years. Idling isn't 100% smooth (occasional very minor stutter) but I am happy with the final results. The cleaning and general tightening up of the TBs also remedied the TB slapping noise I had previously at idle.

 

Thanks to everyone (esp. the Oracle) for the insights and tips.

Edited by Claudio
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