If you recall, Miracle Max pointed out that Mostly Dead is Slightly Alive.
I'm helping out a machinist friend with one of his local charity cases. The guy loves scooters but has no budget. He had two decrepit TaoTao Pony 50s that I repaired into a safe, running, rideable state for him. Unfortunately, both were stolen by the n'er-do-wells of his neighborhood. He got his hands on a third scoot, this 2013 Like 200i and needed help getting it running. Here's what I've done so far.
- checked battery and charged it
- removed fuel pump assembly and replaced the pump/screen with a Quantum kit. Soldered the leads back on the new pump.
- replaced rotten/collapsed fuel line in the pump assembly while it was dismantled. removed pressure regulator and cleaned out fuel passages.
- flushed and drained old fuel snot from the tank.
At this point, it would start and run. Shortly afterwards, it started stumbling and dying at random. I did see a fault code "6" at one point, but the bike has an EFI assembly with a 12/12/14 code on it, so I think it's already been replaced once. Further diagnosis was required, so here's what I did next:
- Previous owner lost keys and destroyed the locks. Replaced the keyswitch set so I could reliably control power to the electricals.
- Reset the TPS/ABV with the pink wire (I hoped).
- Hooked up my Kymco diagnostic box. Got gibberish. Cleaned the diagnostic port with electronic parts cleaner.
- Re-seated the harness connector to the EFI module. Checked the engine grounds.
- removed the injector and had it professionally cleaned and tested. Owner lost the injector clip.
***Intermission while I wait for the Cyclepedia manual to arrive ***
- Reviewed manual for baseline values measured by diagnostic box
- replaced injector clip. For you home gamers, an AC Delco #12579620 kit is a perfect replacement for the OE clip.
- Hooked up the diagnostic box again. Got a good read this time. Confirmed a TPS/ABV reset.
- With the power on but engine off, I checked the TPS with the diagnostic, slowly turning/holding and watching the readout.
- No dropouts and good read from 0-92 degrees, with good sensitivity.
Started the bike again. It's running noticeably better, but stumbles/dies after 30-40 seconds of runtime. You can force it to rev up and it runs cleaner at high revs than low revs. Here's what I checked next.
- Plug was finger tight. Removed plug, cleaned it and re-gapped it. Reinstalled plug with fingers and then added 1/4 turn with a plug wrench.
- Checked the air bypass valve (ABV). It was a little over three turns out of home.
- Removed the ABV screw needle and spring. Cleaned the passage with throttle body cleaner.
- Reset the screw at a hair over 1.5 turns out, lining up the marking paint on the screw head with the paint on the throttle body.
Now the bike starts quickly and idles near perfectly, but still starts stumbling/dying after about a minute. I can run the diagnostic box long enough to make some observations. Not fault codes from the motor and the TPS still seems to read perfectly. Here's what I observed.
- Target idle is 1849 RPM. It runs at 2100 RPM right at startup and settles to 1750 RPM until it's about to die. Then idle drops to 1500 RPM and stalls.
- Injector pulse is steady at 3.32ms until it stumbles, then it drops to 2.5ms before stalling.
- Base ignition timing is 5.5 degrees. Timing climbs to 15 degrees at idle. As idle drops and the engine stumbles, timing advances to 17-18 degrees.
- Timing values suggest I set the ABV screw sorta right.
- Temperature and pressure on a cold engine report correctly, and the values change as the engine warms up.
- ABV doesn't ramp. It's either showing 0 degrees or 100 degrees.
The bit about the ABV is where my interest lies. The manual suggests that this is an active value that settles to no more than 1.5 degrees with a warm engine. The picture in the manual shows an 87.2 degree reading, so I assume it should display something other than 0 or 100.
No I'm going to separate the EFI module from the throttle body to look at the ABV circuit. Hoping maybe the solenoid is binding and just needs cleaning. Really hoping this beater scooter doesn't need another EFI throttle body. Really starting to suspect that this was parked for a throttle body issue and that the wrecked pump resulted from the fuel souring/evaporating in the tank. The electricals were victims of tweakers and morons screwing with technology they didn't understand, which added another layer of annoyance to the diagnosis and repair.
tl/dr;
And now I reach out to you, the brain trust of Kymco ownership! What am I missing here? Am I doomed to needing a new throttle body despite the TPS playing nicely?
