Won’t start when cold but randomly

GRiSO has some problem at cold start but randomly. Some days it starts but some days not.

When pushing on the start button the starter motor tries to start the engine but it doesn’t fire up.

I though it was a Startus Interuptus issue but when I connect a wire directly from the battery to starter motor it doesn’t fire up as well.

Battery is new and well prepared.

Checked fuses, spark plugs but found nothing.

Then took Guzzi Diag and reset TPS and autolearning parameters. Could hear the fuel pump relay when activated manually but no sure which noise it should actually make.

Finally displayed the faults menu and I found the following P0351 and P0352 errors. But it appeared only once because after doing a connect / disconnect sequence with Guzzi Diag it disappeared.

When the engine did fire up by chance I activated manually the stepper motor and found nothing.

When the engine has started once and is warm there is no more start problem.

Don’t know if it is the fuelpump, the phase sensor or the injectors ? Could an injector cleaner to be poured in the tank could help ?

Any ideas ?

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I have had similar problems. I find that when the temp is<15 degrees C, if I have the throttle slightly open and keep it there until the engine catches my cold starting is much easier.

I have had similar problems. I find that when the temp is<15 degrees C, if I have the throttle slightly open and keep it there until the engine catches my cold starting is much easier.

Quote "When pushing on the start button the starter motor tries to start the engine but it doesn’t fire up"

Are you saying the motor always turns over strongly just doesn't catch?

@bowraboy. I’ll try this to help.

@kiwi_roy: Yes it is.

Any ideas with P0351 and P0352 Errors ? It appears that it might be serious if the ECU is involved and no so easy to check the problem.

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Today removed the side covers in order to check if all connections were ok. Found one loose connector on the right side. Fixed it. Then sprayed on all plugs a cleaning for connectors.

Hope this solved the problem.

To be continued …

Richard wrote:

Any ideas with P0351 and P0352 Errors ? It appears that it might be serious if the ECU is involved and no so easy to check the

I'm confused that Guzzidiag is reporting these errors, as they are for the IAW 7SM ECU, but obviously you have the 5AM selected.

Hopefully Beetle may leap in and explain what's going on.

Not so. They are regular OBD2 error codes found in the 5AM. Left & right coil errors. Most likely not the ECU as such. A relay/wiring/ground problem more likely. Assuming the battery is OK.

I think and I hope the problem is solved for good. A loose connector was the culprit. Since I fixed it GRiSO starts like if it was new  

Richard wrote:

I think and I hope the problem is solved for good. A loose connector was the culprit. Since I fixed it GRiSO starts like if it was new  

Just curious. Which connector?

Good question. This is the biggest one on the right side. I can’t say the use of this connector but it separated in two pieces when jiggled a little bit the wires on the right side of the bike.

I’ll take a picture.

The only one that springs to mind is the fuel pump connector.

Yes ! You are right. I checked on the spare parts manual and this is certainly the one.

So much for the OBD2 error codes then.

Here is the loose connector. Fuel pump confirmed. Problem solved so far.

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It stands to reason the bike won't start if the fuel pressure is low due to a bad connector.
Good catch Richard.

And no more cold start difficulties since I fixed this loose connector