She finally arrived (introduction and some questions)

[Midle Age Warrior]

After I follow the kiwiroy instructions (thanks Roy by the way) I tested the ECU connectors measuring resistance and look what I found

 

TPS pin # 1 & #22 2.24 ohms

Pin #11 & #22 920 ohm ->3.35 ohms

Pin 31 7 #11 3.15->1.64 Kohms

Air temp sensor #18 #22 3.43 Kohms 25 degree Celcius

Oil Temp sensor #4 #22 3.31Kohms 25 degree Celsius

Tachometer #3 -> chassis 6.5 Kohms

Injectors 87 relay 5 -> #6 17.5 ohms  #13 17.5 ohms

Coils 87 relay 5 -> #14 0.6 ohms  #20 0.6 ohms

Timing Sensor #7->#12 696 ohms

 

All the values look good enough except the tachometer

 

What do you think

 

TIA

 

[gstallons]

If you own one , use an analog volt / ohm meter and check these same circuits. If you come up w / similar readings . these circuits are good .

[Midle Age Warrior]

An analog Volt/Ohm meter ? To find one will be another challenge hahaha. I will and let you know, thanks

[Kiwi_Roy]

I think your first reading was 2.24 Kohms

Since you have the joints in the loom find the wire that connects to pin #11 and make this available for future TPS Voltage measurements.

The Voltage reference to battery negative (chassis) should go smoothly from about 500mV to 4.5 Volts as you slowly open the throttle.

 

If the tachometer works it's ok the reading shows it's connected.

[gstallons]

If you don't have or can't find one add a test light to the circuit. Ground the test light to the same ground as  the dvom . Check the resistance of the test light. . Remember this value . Touch the tip of the test light to the circuit being tested w/the dvom probe piggy-backed to the point of the test light. Your value should be the sum of the original value plus the test light value . 

 Doing this will test the circuit's ability to carry a load . If there is a bad connection or a bad component this will prove it's integrity or lack of .

[Kiwi_Roy]

Adding a test light is good for measuring Voltage, as you say if you have a weak circuit it will pull the Voltage down but for Ohms all you need is a meter. its not so easy to figure out the Ohms with a circuit in parallel,  1/R = 1/R1 + 1/R2 etc

To measure Ohms a digital meter is probably more accurate than an analog type. Sometimes if you get an odd reading switch the probes around, if you get a different reading something is adding some Voltage to the circuit, a corroded joint for instance.

To measure low resistance electricians pass a current through the circuit and measure the Voltage drop, you can measure down to micro-Ohms that way.

Similarly the diode range of a meter applies a current through a resistor to the diode and the meter measures the Voltage drop across the diode

 

A test light or analog meter measuring Voltage will indicate a rapid change in Voltage better than a digital meter. I particularly like LEDs as their response is instant.

[Midle Age Warrior]

Ok guys I will share with you today's finds.

I verified some circuits, relays, fuses and connections following your suggestions and I would like to say thanks you all.

In my no experience with motorcycle electricity I manage my self to find the circuits I tested in good working order.

the problem althougth persist, when I use the ignition switch nothing happens, but I found that just small amount of movement of the ECU connector bring the fuel pump priming ritual arise, I did the same test many times with the same result just pulling, pushing or twisting of the connector brings the pumps alive.

I did some research in the archives and found this thread

 

http://www.v11lemans.com/forums/index.php?showtopic=17927&hl=%2Bintermittent+%2Bfuel+%2Bpump

 

where TomM said

 

I had an issue a few years back where my fuel pump was not consistently priming when I turned the key on or cycled the kill switch.  I eventually figured out that I could make it prime every time by moving the wire loom around at the ecu connector.  My ecu was mounted with the connector facing up and apparently the seat base had been flexing and hitting it which eventually cracked an etch in the ecu PC board.  I installed my other TI ecu with the connector facing down and haven't had any problems with the fuel pump since then.

 

If the bike in question has the same symptoms that I had and the ECU is mounted with the connector facing up the mechanic might want to try moving the wires around with the key on to see if that makes the pump prime.  If so it's probably either a wiring or an ECU problem. 

 

 

I had the exactly same problem and I would like to know if there are some specific ways to test the ECU or connector in order to isolate the problem

In case the problem comes from a faulty ECU, are they fixable or if not could you suggest a place to find a new/used one maybe some fellow member has a spare one for sale

TIA

Roberto

[luhbo]

Search ebay for 'ecu' or 'cdi' and marelli or ducati or guzzi or WM15 and the like. You can reflash all of them to the version you need.

You can try to resolder the joints on the ecu, but you shouldn't expect to much. These pcbs are rather fine pitched and probably multi layer, too.

On one of your pix I've seen that the ecu is already opened. Did you buy it open or did you open it yourself?

That's what I meant with 'Good Luck' when I saw this.

 

Hubert

[Midle Age Warrior]

Guys

I feel so sad since my bike is sitting in the garage while the technician is taking care of the ECU, we found some cold welds (we called in spanish a bad weld due overheating caused by a bad contact I guess).

I have not time right now to spend in the bike, but soon the Xmas holidays will give me some to fix the problems I hope.

I will let you know.

[Kiwi_Roy]

By cold weld I think you are referring to tiny cracks around the pins, that's a sign of pressure on the connector, once your technician has re-soldered them you should be good to go.

Re-install the ECU with the plug underneath so the seat doesn't push down on the connector.

Consider tapping into the wire from the ECU slider (pin 11) so it's easy to set the TPS, just solder to the wire where the previous owner joined the loom.

Check all the joints he made, solder and heatshrink if possible and you won't have any more trouble.

[Midle Age Warrior]

Thanks Kiwi_Roy I will keep you guys update