1100 Sport sputters

[lemppari]

A fellow Guzzista in the finnish forum is in trouble with his 1100 Sport. After a few km:s the engine suddenly starts sputtering, but only at over 2000 revs! If he keeps the revs below that, the engine runs normally and idles well. After a while the problem dissappears, only to start again a little later.

 

The battery voltage was measured at 12,8 and a normal charge current.The owner is able to read the failure memory which gives codes 3-3 and 1-6. They are petrol pump cutout and battery voltage failure.

 

Could someone offer a plausible explanation?...Raz maybe?

[raz]

First, the ECU can not actually make the diagnose "petrol pump cutout" with any certainity, as it

 

a) does not get any feedback on actual fuel pressure, and

does not get any feedback on [electrical] pump current.

 

It could theoretically sense that the current passing the power relay coil is too small, but that would be it. If that's the case, the correct error description should be power relay coil cutout, although the fuel pump (as well as the injectors and spark coils) will obviously lose power as a result. I have no idea what the code really means. It could even be just "deceleration when expecting acceleration" and in that case this error would also pop up if you run out of fuel or even outpower the engine with your rear brake.

 

I would check the power relay and the ECU relay (and why not all relays) as well as the ground strap fitted to the ECU cover. Relays are said to be failure prone but I think the sockets are even worse. Clean them and grease with battery pole vaseline, and perhaps even use zip ties around the relays (I've had the power relay pop out of its socket twice in 150 kms!). In case a relay is actually bad, swapping them around should make the problem move or go away.

 

When this appears, does turning off headlight make any difference?

 

Ignoring the codes (sometimes they are just there to confuse you) I would replace the fuel filter.

[Murray]

12.8 volts is a bit low if the bike is running the listing for the 1100 sport is 14.5 volts @5000rpm +-0.2 . Has the bike sat for a period of time the fuel pumps tend to foul up in this case. The other thing it could be is a coil breaking down under load/heat.

[Kiwi_Roy]

A fellow Guzzista in the finnish forum is in trouble with his 1100 Sport. After a few km:s the engine suddenly starts sputtering, but only at over 2000 revs! If he keeps the revs below that, the engine runs normally and idles well. After a while the problem dissappears, only to start again a little later.

Don't rule out over voltage,

I have seen some weird effects with my bad regulator, one of them cutting off and on with revs. I suspect there is something in the ECU that causes it to cut out if the regulator is overcharging.

This would be very easy to check, just pull off one of the yellow wires coming from the alternator to regulator thus dissabling it for the test.

 

As Raz says check the relay bases for tightness, I found one connector in my relay bases not gripping at all, it's well worth spending a couple of hours removing & tightening them up.

 

Roy

[lemppari]

Don't rule out over voltage,

I have seen some weird effects with my bad regulator, one of them cutting off and on with revs. I suspect there is something in the ECU that causes it to cut out if the regulator is overcharging.

This would be very easy to check, just pull off one of the yellow wires coming from the alternator to regulator thus dissabling it for the test.

 

As Raz says check the relay bases for tightness, I found one connector in my relay bases not gripping at all, it's well worth spending a couple of hours removing & tightening them up.

 

Roy

The colleque told me to thank you guys sincerely for all the advice. He went and took the tank and covers etc. off to check and mend the wiring and connections and voltage thorougly.

 

This goes to show once again how one gets helped round here. Or is it simply because we all are in the same leaking little boat in a huge electric storm called 'Made in Mandello'?