Modern Vespa

I've been trying to fix an intermittent starting issue for over a year. For complete details see "Started as a spark plug post; now down the rabbit hole we go." at:

Started as a spark plug post; now down the rabbit hole we go and/or the associated posts at: 2015 GTS300 fuse locations and amp ratings and Wiring help on 2015 GTS300

I'm clueless, but the the forum members have been helpful and patient. Today, after another day of fruitless "troubleshooting", I developed a new repair methodology, "The Throttle Body Tap". I put the video on YouTube because it really has to be seen to be fully appreciated:

https://youtu.be/x553cvOdzG8

Thoughts? I didn't see this in Piaggio's shop manual for the GTS300...

Pretty common unfortunately. Usually one or more pins of the ECU plug get a cold solder joint so the ECU will work fine when you give it a tap. If you narrow down which pin is the culprit you can heat it with a soldering iron and gently give it a pull. Have done it on a few ECUs. Some worked, some didn't...

RANT WARNING (please skip this post if you don't want to read my mini-rant): Thanks. It's pretty disappointing to hear that this is common. Who is soldering Piaggio's ECU's? Mr. Magoo? My seven year-old kid? Someone going through alcohol withdrawal?

Your suggested fix seems impossible for me to accomplish, but it did prompt me to look up "cold solder joint" on the internet... How would one get to the solder locations for the pins on the ECU? Given my limited abilities, it's probably more efficient for me to just tap the ECU every time I ride the scooter.

Seriously, though... Is there anyone in Connecticut (or MA or RI) that thinks they can fix this Vespa? If not, does anyone want to buy it? Here's the posting- 2015 GTS300 with 9500ish miles... Doesn't run, but it will turn over if you tap the ECU.

I put my battery on the trickle charger last night (it was getting low due to my "troubleshooting" efforts).

This morning I went out to make an attempt to start the scoot... Click. I gave it the ol' "Throttle Body Tap" and tried starting a few more times and...

After the customary multiple "turn overs", the scoot started up and ran for the first time in weeks!

So, thanks to SaFis and the other forum members for their assistance. I might rename the "Throttle Body Tap" to the "ECU Tap". And I'll be petitioning Piaggio to include the "ECU Tap" in their future shop manuals. I'll also be nominating Piaggio's electronics department for the prestigious "Vehicular Electronics Soldering of the Year" award. Note: The last two sentences were sarcastic.

Here's the question: Could a poorly soldered ECU pin be causing all these frequent starting problems, which include both clicking through the starter relay (without turning over) and also turning over (without starting)?

Yes. Dry joints, wherever they are, can cause problems - often heat-related as the materials expand or contract.

First I've heard of bad joints in the ECU, but it makes sense. It was a common fault in the early MP3 turn signal/hazard warning 'relay'.

theschuman, relax...it's not that common at all. Only ever encountered it on a Suzuki Burgman 650 on one occasion. It's new to me to hear it's common on GTS range of bikes and I simply haven't heard that one. If it was common I'd know about it. Not saying someone hasn't had that issue, but it will in the overall event of things be a tiny problem that few of the millions of these bikes ever experiences.

In the past few years on MV there have been quite a few reports of random stalling of the GTSs in the USA, eventually cured by replacing the ECU. I wonder if these were just down to dry joints between the connector pins and the circuit board.