Herald Mirage 125 EFI Bogging Problems

[Sulez]

Hello, ive got a herald mirage 125 same as the lexmoto tekken and i had a bogging issue, when i open the throttle the bike dies completely if i constantly twisit the fthrottle fast the bike will rev up. I have replaced the whole throttle body and this made no different i even fitted a new injector because i though it was fuel related. Before you say its compression i checked this first and it read 150psi which is perfect so i believe its a wiring issue but i dont know what it can be, can someone point me in the right direction. Also i have changed the spark plug and put fresh fuel in the bike, also did the valve clearances 0.00y for intake and exhaust.

[Easy-X]

Let's quantify this situation, might be helpful...

Is this just in neutral or while riding? Does it idle okay? Whereabouts does it bog out? half-throttle, three quarters, etc.

You've bought new parts that didn't make a difference. Did you put the old parts back? (Sometimes you can make things worse by introducing new variables.)

Fuel, air and spark are the essentials. Throttle body and injector are the endpoints but is enough fuel coming out of the tank? Don't know this bike but it probably has a tiny fuel pump either inside or external to the tank, maybe that's the problem.

Have you checked the air filter and intake for blockages? Have you tried taking the air filter out to see if it's better or worse?

Finally spark. Always worth eyeballing the plug out of the bike to check the spark is bright and strong. After that I'm wondering if it's a timing issue as that would change as you go up the revs. Maybe a cam sensor fault?

Oh, and any engine warning light on this bike?
____________________
Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Nobby the Bastard]

Did you do something to it just before the bogging down started?
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[WD Forte]

Year? mileage? and as above, any eml light flashes?
____________________
bikers smell of wee

[Sulez]

The bike starts up fine, when i rev it half throttle it will bog but if i rev it very fast with multiple twists it will rev up abit higher but then still bogs and the engine light comes on randomly and goes off thats whilst it is started btw. I scanned the bike and it was saying a pending fault P0107 "Manifold Absolute Pressure" this code is caused by a faulty MAP sensor but this bike doesn't even have a MAP sensor so i am very confused. Also i have put the original parts back on the bike and no difference was made and i checked the fuel, aire and spark there is a very strong spark. There is plenty of fuel coming from the tank and i replaced the fuel pump/injector they are both one part on this bike not separate. It has a external fuel pump that bolts up to the top of the injector then into the throttle body.

[Sulez]

[Sulez]

[Sulez]

i believe it is a intermittent wiring issue because the bike randomly was working fine then when i switched it off and tried it again the bike went back to bogging, so its definitely some wiring issue. Does anyone know if there is some sort of hidden relay or something that would cause this issue or which wires should i check, i wonder if the ecu is faulty could this cause this issue? i did unplug it and re plug it to see if it would fix anything but sadly didnt

[Nobby the Bastard]

Does the EML light flash when you turn it on?
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[WD Forte]

It probably does have a MAP sensor but like most small EFI singles
it's part of the throttle body assembly which has the TPS MAP and IAT
all in the same unit.
YBR's have this as did the Honda Forza I worked on/fixed recently
when I replaced what Honda called the above the sensor unit.

'hidden relay'? as in what they dont want you to know about?

it sounds as if you're playing swap and hope and making assumptions
Not best practise, test dont guess is a better method.

I'd start by opening checking and cleaning all electrical connectors and
ensuring the bike has good consistent grounding throughout.
EFI only uses a 5v supply to most sensors and the signal levels are even lower than this, so bad connections or grounding can easily give it conniptions.
____________________
bikers smell of wee

[Sulez]

[Sulez]

[WD Forte]

Sounds like typical chinese crap then
Burn it
____________________
bikers smell of wee

[Sulez]

[slowasyoulike]

[WD Forte]

That video's got a god awful CG voice track
fuck that, I bailed 10 seconds in but did spot a pic of the combined IAT and IAP sensor on the inlet tube forward of the throttle body


The bike uses a Delphi ECU
probably an MT05
fault code P0107
"open circuit for intake pressure sensor
or
signal end pins shorted to battery negative"

This means its getting either a too high or too low a voltage
on the ECU's IAP pin
the ECU will expect to get voltages between say 1.5v and 3.5v
on this pin and anything out of bounds will trigger a fault

Its either bad connections or the sensor unit has failed
not magic hidden relays

https://imgur.com/vhp9rya.png
____________________
bikers smell of wee