2015 uxv 700i starting problems

[ARVenne]

Hi I am new to this forum so bear with me
Bought the uxv new it had starting issues from day one, never showed a code on diagnostic tool or CELP
The unit always started fine cold but after it warmed up I had to wait a few minutes after shut down before I could start it.
had it back to the dealer they could find no problem even though it would not start for them several times
This starting issue has been progressively getting worse, All sensor check out to spec, all wiring is good, have changes WTS, has a new ECU, new battery, new starter.
have had several technicians look at it nothing shows up, fuel injector has been changed also. lots of fuel pressure, rollover sensor is good.
One of the annoying things is after checking everything for the 100th time,it will suddenly start and work for several starts and then not start again for days.
Can anyone tell me if there is a way to check the CSP sensor other than the ohms.
What it does is at start up is the fuel injector will only pulse once, and then stop so a sensor or something is telling it to stop pulses, it has ignition spark all times, 12V to injector is good, the ohms resistance is good. Fuel pump is working and voltage and pressure are good.
when it does not start the diagnostic tool shows the cranking rpm as 296, timing is at 3.7, tps .68V, roll over .73V , no injector pulse it reads 0
when it does start diagnostic tool shows correct rpm, timing changes as rpm is increased etc. rollover is .73V, injector pulse is 4.2ms at idle and changes as rpm increases.
We have checked all grounds, relays etc.
Question has any one else run into this and is it possible it is a faulty plug on the ecu? Is there a voltage check for the impulse from the CSP sensor?
Appreciate any help any one can offer
thanks
arv

[CROSSBOLT]

Probably like my UXV500i got hard to start: battery. Seems like ALL Kymcos have a marginal starting system linked to the battery.  Check the battery. It is probably a white label cheapo the dealer tossed in there. Or it could be like most of the 500 and up Kymcos with a battery that is marginal. Got a voltmeter? Stick it on the battery or the accesory outlet and see what the volts are when you try to start. anything below 10.5 is notice to get the biggest, highest quality battery  you can find to replace what is in there. What I did with mine was to parallel a marginal lawn & garden battery with the original battery(also marginal after two seasons) which solved my starting problem. Try the start voltage check with your battery jumped and see what happens. 10.5 volts and below is no good.

[ARVenne]

Hi Karl thanks for the reply
I was aware of that voltage issue and have my unit set up with dual batteries and both are new and top line batteries
I have checked starter solenoid and it tests out fine
But inspite of testing good i have often wondered if it is the problem voltage loss across solenoid is less than half a volt while cranking

[CROSSBOLT]

Loss of half a volt? What is the voltage?

[Stig / Major Tom]

It's a 2015, warranty starts when you buy. Is it still under warranty?
If no longer under warranty.....
You've done way more than any new owner should!
Invoke lemon law, or copy all your paperwork and register mail it to the name and address of the customer care person you've spoken to on the phone at Kymco USA.

If it's under warranty - you might try doing what I did. Speak with Kymco customer care guy, leave it at the dealer until sorted and repaired. Let him do the heavy lifting with your dealer....or offer you some sort of agreeable compensation.
I just left it there and said please call me  when repaired.
Things began moving nicely, after weeks passed, when I finally placed a video of the issue on youtube.

In short, this is not your mechanical problem to fix. Your machine was not right from the get-go!

Just my 2 centimes....Stig

[ARVenne]

Thanks for the imput, first the voltage at the battery and at the battery side of the starter solenoid is 12.4 volts while cranking  but not starting the voltage across the  solenoid is 11.8 volts so a lost of .6V this seems to vary a bit so I assume its because after repeatedly trying to start the unit the battery voltage drops before I recharge the batteries.
Surprising enough is the unit started 6 times yesterday while I was testing different wires, connections etc. then just as usual it stopped pulsing the injector and still no error codes showing on diagnostic tool.
Is it possible that the ecu pin from the injector is faulty?
The injector signal wire  checks out fine, but a zero resistance in a wire does not mean it will carry the full voltage to tell the injector to pulse (several broken strands of wire will cause a resistance under load) or am I not correct in this?
There is a full 12.4 voltage going to the injector on the power side.


As far as taking it back to the dealer, the dealer I bought it from is still in business but only sales not repair, the nearest Kymco repair is a 9 hr drive from here. I have been in contact with them and they are aware of whats going on but can't even offer a solution without me hauling the unit to them.

[CROSSBOLT]

Stig is right (as usual!) about the warranty. You may be able to work out with your Kymco rep and the dealer a parts supply to fix the problem. I did this with a dealer in Nashvile, about 2.5 hours away. Parts may not be required since your cranking volts are great! This recent information is screaming that one of the required grounds is intermittent.

[ARVenne]

Found the problem!!
Nothing to do with faulty sensors or ecu
At the factory when they set the throttle plate stop screw it was actually holding the throttle plate open!
That made the TPS settings incorrect also caused the TMAP and ICS to not work properly
Adjusted it to keep plate fully closed and niw starts every time This also allowed proper idle speed of 1400 rom instead of 1800 got rid of stalling issue when going down hill made shifting easier no more engine knock when you step on accelerator and no more occasional back fire when you have to let off gas at higher rpm
Diagnostic tool never showed a code for this although when checking ICS the numbers where alover the place
That little extra airflow around the butterfly was just enoough to mess things up. The screw was locked and had factory paint on it for position so this was done at factory! Once i reset this screw and TPS everything works ! After 3 years and $2800 in prts and wasted labour I now have a properly running UXV!
Going to pursue this with dealer and manufacturer. Thanks for all your imput!!