Another idle question

pencilbeam · Post by **pencilbeam** » Sun May 20, 2007 2:54 pm

Hello to all,
I've posted some replys to a few simple mechanical problems and just had one myself. Coming back from a ride a few weeks ago, the bike just died, but luckily restarted and ran just enough to make the 1/2 back to my garage. I was afraid it was a bad fuel pump, but after reading this forum, I followed some of my own advice and cleaned the relay connectors and fixed the problem! Happy days, right? Now for some reason, the bike won't idle smoothly and will die if I don't keep the fast idle above 1,200.

Any guesses for an obvious problem to check for? I've just been through the entire bike cleaning every single contact, checked the plugs for fouling and they look identically good. In the last 1,000 miles I've checked the valves, replaced the belts, rechecked the belt tension, changed the oil twice, flushed the radiator, replaced the coolant, new plugs, new fuel injector hoses, cleaned the injectors, checked the battery voltage, disconnected the battery for a while to see if that would reset the computer, and alot of other stuff not related to the engine. The bike has high mileage; 89,000, and never goes to a shop. I'm thinking of following Finn Pasos advice and (having someone else check my fuel injection system.)

The bike has been pretty much stone reliable all this time and has no surging or sputtering. As I said, it also never visits a shop, so perhaps it's time.

Anyway, did I miss something? Does anyone know of a Weber-Marelli expert in Souther California?

Best regards,

Jim

Post by **jcslocum** » Mon May 21, 2007 12:38 am

Did you replace the fuel filter?

Does the 907 have a TPS (throttle position sensor) that might need to be set?

Jon

pencilbeam · Post by **pencilbeam** » Mon May 21, 2007 4:05 am

Yes, it has a brand new fuel filter. The battery is getting old (4 years) and I haven't checked it above idle. It keeps a steady 12.6 volts at 1,000 rpm.

I think it does have a tps, but don't know how to check or set that.

Thanks.

cagiva905 · Post by **cagiva905** » Mon May 21, 2007 5:34 pm

Could be a number of things. Did the problem occur right after you cleaned the contacts? If so, it could be the whole system was setup and corrected against the dirty contacts (high resitance), and now is getting "weird signals".

It could be the TPS, that one is located on the right side of the throttle bodies.

Could also be bad throttle synchro, although the efi system is not known for getting out of sync.

Michiel

pencilbeam · Post by **pencilbeam** » Mon May 21, 2007 6:36 pm

cagiva905 wrote:Could be a number of things. Did the problem occur right after you cleaned the contacts? If so, it could be the whole system was setup and corrected against the dirty contacts (high resitance), and now is getting "weird signals".

It could be the TPS, that one is located on the right side of the throttle bodies.

Could also be bad throttle synchro, although the efi system is not known for getting out of sync.

Michiel

Thanks for the reply, Michiel.

The bike idled smoothly before the fuel pump relays faltered. I think the system was set up to spec, since the bike performed so well before. I found a Cagiva Elefant website to follow to check my TPS, so that will be the next thing I do. Are the throttle body synco screws the ones on the right side that have an "O" and a "V" I may have inadvertently moved them, making the problem worse. There may be a few more contacts to check and I plan to take the injectors out for inspection.

cagiva905 · Post by **cagiva905** » Mon May 21, 2007 6:58 pm

if you mean http://www.endless-horizons.net/efi/efi.htm, I am actually the owner of that website, hehehe. Took me a while to get all that info collected, so I put it there for everybodies use, including 907 and lancia delta owners.

The synchro screw is a spring loaded screw on a quadrant between the left and right throttle body axes. On the Elefant this is also where the throttle cable is attached. I assume this is more or less the same on the 907. To access it, this means you have to remove the tank and airbox in order to be able to setup synchro. The screw must be turned from above. There are idle set screws on each throttle body, and the manual describes how to setup both of them. However, if you look at this logically, you will realise that you only need one of them (I use the one most easily accessible, the other is screwed out so it will not bother me..).

If you turned one or both of these , it is possible you just set idle too low, making the bike feel a bit jerky at idle and just above.
Given the mileage of your bike (especially if this are actual miles in stead of km) and assuming it has never been overhauled, a slightly higher necessary idle speed is not uncommon. 1200 rpm is not too bad for that matter.

The fuel injection system on our bikes has the reputation of being complicated and difficult to work on. However, this is more myth and fear than reality. The mechanical part of the system is quite simple, and not easily disturbed. The throttle bodies hardly ever run out of sync. If problems occur, most of the time it is because somebody fiddles with it wrongly or by accident, or one of the sensors fails. For the latter, first to go are temperature sensors.
Sometimes the TPS fails, but not often. This is an automotive part designed for long mileages (however, still italian quality, hehe).

Feel free to ask if you need assistance.

Good luck!!

Michiel

pencilbeam · Post by **pencilbeam** » Mon May 21, 2007 7:17 pm

I have been on your site! Very good. The most recent one I checked out was http://www.elefantriders.com/fuel_injection.htm.

I'm going to check my temperature sensors and idle set screw again.

Are those expensive to replace if bad?

I will post again after that. Much appreciated.

cagiva905 · Post by **cagiva905** » Mon May 21, 2007 9:08 pm

Ah, Paul's site. Nice one, and some very nice stories on there,

. Paul knows his way around bikes as well.

Replacing the sensors costly? I think that depends what part of the world you are and where you source them. The original part numbers from Ducati don't come cheap. However, the same sensors are used by other bike and car brands, and they all have their own pricing methods. And than there are the aftermarket suppliers, often eaven cheaper.

Check the alternatives on my website, you can find links to most suppliers on the link page.

Example: Here in Holland is a Water temp sensor from Ducati approx. 80 euro. Air temp sensor (in the airbox) is even more expensive.
I ordered both from a german shop (Augustin) an paid less than 75 euros for the both, including shipping! I received alternative brands (Facet and Beru), but the characteristics were ok. Should be off course, for replacement parts. That was several years ago and my bike still runs on these sensors.

On the Elefant the water temp sensor brakes down quite often due to the awkward location of the sensor, prone to rain water intrusion in the connector. I don't know how that is on the 907.
You can check the sensor heating it in hot water, checking resistance against temperature with an ohmmeter and a thermometer.

Same goes for the air temp sensor, ony use a hair dryer in stead of water

.

Faulty temp sensors make the bike run bad all over the rev range, and are more temp related than rev related. My guess remains that you only should have to adjust idle again.

Should you decide to check synchronisation, be sure to use a decent quality balancer gauge. I learned the hard way that the cheaper ones often lack just the final accuracy that you want to have the bike run perfect. Best ones are mercury gauges or alternatives.

Michiel

Ducman · Post by **Ducman** » Tue May 22, 2007 12:40 am

I went out for a ride today and stopped for a coffee after about 50 miles or so... and the idle stayed up, around 2000 or so, blipped the throttle but didn't come down. Had my coffee and cursed all things with breasts and wheels, fired her up and it ran fine, a hundred miles later I am left scratching my head

the bike runs fine...I think its laughing at me :neener:

cagiva905 · Post by **cagiva905** » Tue May 22, 2007 6:20 am

Sounds like a throttle cable problem, or perhaps dirt around the throttle body return springs.

Michiel

Ducman · Post by **Ducman** » Wed May 23, 2007 2:03 am

thanks for the tip
cheers

du907 · Post by **du907** » Sat Jun 02, 2007 1:36 am

The TPS hardly ever needs adjusting. However, go to the site http://www.fuelinmoto.com.au/ and it will discribe how to adjust the TPS. After adjustment, you have to balance the throttle bodies, then the air screws, the enrichment screw on the ECU all in a certain order. It is very involved. I have done it, you will need long lengths of fuel line so you can move the tank out of the way and still keep it hooked up. You will need a vacum guage balancer, an ohm meter, like I said, very involved and you probably don't need to do it. Also, you will have to have a CO2 meter to check the mixure to adjust the enrichment screw to 3% or take it a shop that can put a sniffer up the tail pipe to get the readings.
Fast idle that will not come back down to normal after bike is warm, then goes away. Comes back every now and then. . . . .
Check the water hose under the tank on the left side. The "choke" linkage and the throttle cable attach on the same side. The throttle bodies butterflies shaft with a nut and washer on the end will rub against the water hose that expands when hot. Use large wide zip ties, 2 or 3 to pull the hose close to the frame when cold so that when the hose warms and tries to expand, it will not rub the throttle body linkage and shaft.
The idle adjusting screw on the left throttle body is accesible from the front opening in the fairing behind the front wheel. The right side is not accesible, however I removed the air filter exposing the inside of the air box and drilled a hole through the bottom "floor" of the air box right on top of the screw. I then used a rubber plug to seal the hole after adjusting. I generally adjust it first, just letting it get close, then use the left side screw to set the idle.
Also I have a wiring diagram and pictures of a code reader that you can make to read the fault codes from the ECU. The codes are in the service manual on this site and that will tell you which parts in the fuel injection system that are failing.
Good luck

pencilbeam · Post by **pencilbeam** » Tue Jun 05, 2007 2:24 pm

Thanks very much, I found one of my air screws dropped out of the vertical manifold, so I screwed it back in and closed both of them. I'm planning on getting a friend to use his shops co meter to rebalance them and I will keep you posted. Best regards.

du907 wrote:The TPS hardly ever needs adjusting. However, go to the site http://www.fuelinmoto.com.au/ and it will discribe how to adjust the TPS. After adjustment, you have to balance the throttle bodies, then the air screws, the enrichment screw on the ECU all in a certain order. It is very involved. I have done it, you will need long lengths of fuel line so you can move the tank out of the way and still keep it hooked up. You will need a vacum guage balancer, an ohm meter, like I said, very involved and you probably don't need to do it. Also, you will have to have a CO2 meter to check the mixure to adjust the enrichment screw to 3% or take it a shop that can put a sniffer up the tail pipe to get the readings.
Fast idle that will not come back down to normal after bike is warm, then goes away. Comes back every now and then. . . . .
Check the water hose under the tank on the left side. The "choke" linkage and the throttle cable attach on the same side. The throttle bodies butterflies shaft with a nut and washer on the end will rub against the water hose that expands when hot. Use large wide zip ties, 2 or 3 to pull the hose close to the frame when cold so that when the hose warms and tries to expand, it will not rub the throttle body linkage and shaft.
The idle adjusting screw on the left throttle body is accesible from the front opening in the fairing behind the front wheel. The right side is not accesible, however I removed the air filter exposing the inside of the air box and drilled a hole through the bottom "floor" of the air box right on top of the screw. I then used a rubber plug to seal the hole after adjusting. I generally adjust it first, just letting it get close, then use the left side screw to set the idle.
Also I have a wiring diagram and pictures of a code reader that you can make to read the fault codes from the ECU. The codes are in the service manual on this site and that will tell you which parts in the fuel injection system that are failing.
Good luck

pencilbeam · Post by **pencilbeam** » Wed Jul 11, 2007 1:43 pm

So as a follow up to my original thread, idle problem is solved. Finally took it to a shop. The service tech really didn't want to look at it, but was able to run a CO meter and balanced the thottle bodies for idle and lower rpm.

I found that my water hose was rubbing against the end of the throttle return spring and carefully pulled it against the frame.

The tech found that the speedo cable was routed incorrectly and hitting the fan, which could be causing the bike to run hot.

Total cost $63. Bike runs like new.

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