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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 20, 2021, 06:51:00 PM »
any news with dt300?
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General Discussion / Re: how many Miles Per Year are you riding?
« on: December 20, 2021, 01:47:13 PM »
last year with DT350 11,000 miles, for next years could be higher because I change work place and now I travel to city centre where is impossible find parking spot for car, so for next year could be higher, nothing cant stop me riding during the winter, no problem with subzero temps but heavy rain is big problem because manhole issue in my city, during the rain they popup and sh!t happens, last year I crash... ran into a hole..
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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 17, 2021, 05:37:53 PM »
Hm intresting...
Can you use starter from 350 and 95 fuel before you buy new starter?
Can you use starter from 350 and 95 fuel before you buy new starter?
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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 17, 2021, 12:00:44 PM »
My DT also doesent crank fast, you can always try jumpstarting while hot, you need couple second for that.. but for me that is dead end if starter behaves same during the cold and hot start.
With such an attitude then you may wonder such question before any attempt at repair? Dont you?
Main two reasons:
1: engine wear, everything changes over a period of time, when engine is "young" compression is stronger, there is more temp and pressure to better handling the bigger preingntion time....etc
2. during the distillation of oil hundreds of additives are added that can vary what can lead for engine problem that is why (at least in my coutry) sometime when I top up my tank on some gas station I have trouble with engine performance and idle speed, that counts more for my car then scooter, but you get the point.
Why you dont remove all fuel from disassembled scooter, you can use fuel pumpe to remove all present fuel, and you can add few liter of 95 fuel.
What I wrote about the octane value of fuel, I didn't get it out of my head randomy, I know few people who try that premium fuel (in my country its call 100 ocatin) what caused only starting issue...and also beacause I know how much an"impact" higher octane fuel have on ECU calculation because I do that for long time.
Quote
Why the engine has been working good for years on 98 then ? I promess I'll feed with 95 !
With such an attitude then you may wonder such question before any attempt at repair? Dont you?
Main two reasons:
1: engine wear, everything changes over a period of time, when engine is "young" compression is stronger, there is more temp and pressure to better handling the bigger preingntion time....etc
2. during the distillation of oil hundreds of additives are added that can vary what can lead for engine problem that is why (at least in my coutry) sometime when I top up my tank on some gas station I have trouble with engine performance and idle speed, that counts more for my car then scooter, but you get the point.
Why you dont remove all fuel from disassembled scooter, you can use fuel pumpe to remove all present fuel, and you can add few liter of 95 fuel.
What I wrote about the octane value of fuel, I didn't get it out of my head randomy, I know few people who try that premium fuel (in my country its call 100 ocatin) what caused only starting issue...and also beacause I know how much an"impact" higher octane fuel have on ECU calculation because I do that for long time.
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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 17, 2021, 11:16:43 AM »Sounds possible to you ?
If you didnt notice starter is struggling or hesitates while cranking hot, and also when we take in consideration lower voltage and battery capacity when it's cold which is also a limited factor for the starter. No it is not possible in my opinion!
for god's sake try other fuel
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General Discussion / Re: Why aren't scooters seen as manly conveyances in the USA?
« on: December 15, 2021, 07:04:22 PM »Insurance, taxes and other payments sum up annually only for my DINK 200i (174cc) around €1.000,- without fuel. For my car it's around €2.000, anually.
Holy sh!t, you pay 1000Eur tax, insurance and registration for 174cc scooter? Where u from? Qatar
It is insane price compare to mine..
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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 15, 2021, 11:10:05 AM »
Vacuum is strongest at idle when throttle clamp is closed, so if there is any air leak map value will be higher, out of spec, and also unstable.. you said map readings are good so I doubt there is air leak somewhere.
About O2 cycling missing that can point to some software issue howevere that would not have impact on hot start as I mention before ECU is in open loop, BUT if we discover one ECU weak spot that is pointing there can be more like hot start problem!
But still 98 fuel bothers me
About O2 cycling missing that can point to some software issue howevere that would not have impact on hot start as I mention before ECU is in open loop, BUT if we discover one ECU weak spot that is pointing there can be more like hot start problem!
But still 98 fuel bothers me
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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 15, 2021, 10:41:22 AM »
Injector is placed before intake valve, so it is same volume space as map sensor (manifold absolute pressure) location, and bad oring or manifold gasket or any other damage will have impact on map readings! About powder, goal is make dust so you can see air moving you can use indinan stick too to make smoke. From my experience when injector oring wear and doesent seal, there is characteristic high pitch sound because of flow air thoroug small place!
I hope you get clear picture now
I hope you get clear picture now
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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 14, 2021, 10:37:58 PM »
Oh here is so much troubleshooting lol
About any air leak ...etc.. you can test that with Fi tool, just watch MAP pressure value, it should be steady on idle like 35-45 (also observing rpm so you will now why pressure rise or drop) if you have steady rpm and your pressure change, that is indication for something!
You dont need to test ECU with multimetar like Ruffus write, you do all that with FI tool, dont waste time
Also tilt swtich is good according the FI tool!
About that black stuff on fuel filter, I dont think that make any issue because you have good pressure!
Conclude; ECU read all good value, so could be wrong handling through the software or my theory (read bellow)
O2 sensor cycling on idle is way how ECU preform injection timing however it need some time to start cycling you should put some rpm-s. Not cyclinging on idle can indicate air leak (you can test that observing MAP pressure or baby powder method), O2 sensor problem or ECU software problem, in my experience I encountered all three problems
I write you before... try play with throttle and observe O2 behaviour and report here...
Now I will write what I think what is the problem (my fameous theory), after read all post my conclusion is FUEL! I know first you gonna think it is premimu fuel must be good etc... However you have trouble with two identical scooter, identical hot start problem....and you said you feed them with 98 fuel, that could be a trick!
Well, we should look wider picture, EFI in DT300/50 is basic I would say primitive if we compare some other systems...
System lacks of auto-adjusting feature for fuel octane, so it can make trouble advancing ignition timing during start because of ignition map limitiation if you pour higher octain fuel. When engine is cold ECU advance igntion more then hot, that is why you dont have a problem, however that changes when engine is warm, there is no need for too much advanced igntion and ECU retard it and makes trouble beacause of fuel resistance (bigger preigntion time). What I wanna said, iginition map is fixed and adjusting for higher octain fuel is not possbile so you should remove all the fuel and put 95 octain fuel, start engine leave it work some time to clean all remain fuel, get some rpm-s (I assume you cant drive because it is not in one piece) and test hot start. Maybe is "shot in the dark BUT" like Crossbolt write, but for sure you would not be the first with such a problem related with fuel octane. There are not many "cases" related with octain value but they exist and main problem is engine starting not performance so give it a shoot you gone loose few Eur on fuel
About any air leak ...etc.. you can test that with Fi tool, just watch MAP pressure value, it should be steady on idle like 35-45 (also observing rpm so you will now why pressure rise or drop) if you have steady rpm and your pressure change, that is indication for something!
You dont need to test ECU with multimetar like Ruffus write, you do all that with FI tool, dont waste time
Also tilt swtich is good according the FI tool!
About that black stuff on fuel filter, I dont think that make any issue because you have good pressure!
Conclude; ECU read all good value, so could be wrong handling through the software or my theory (read bellow)
O2 sensor cycling on idle is way how ECU preform injection timing however it need some time to start cycling you should put some rpm-s. Not cyclinging on idle can indicate air leak (you can test that observing MAP pressure or baby powder method), O2 sensor problem or ECU software problem, in my experience I encountered all three problems
I write you before... try play with throttle and observe O2 behaviour and report here...
Now I will write what I think what is the problem (my fameous theory), after read all post my conclusion is FUEL! I know first you gonna think it is premimu fuel must be good etc... However you have trouble with two identical scooter, identical hot start problem....and you said you feed them with 98 fuel, that could be a trick!
Well, we should look wider picture, EFI in DT300/50 is basic I would say primitive if we compare some other systems...
System lacks of auto-adjusting feature for fuel octane, so it can make trouble advancing ignition timing during start because of ignition map limitiation if you pour higher octain fuel. When engine is cold ECU advance igntion more then hot, that is why you dont have a problem, however that changes when engine is warm, there is no need for too much advanced igntion and ECU retard it and makes trouble beacause of fuel resistance (bigger preigntion time). What I wanna said, iginition map is fixed and adjusting for higher octain fuel is not possbile so you should remove all the fuel and put 95 octain fuel, start engine leave it work some time to clean all remain fuel, get some rpm-s (I assume you cant drive because it is not in one piece) and test hot start. Maybe is "shot in the dark BUT" like Crossbolt write, but for sure you would not be the first with such a problem related with fuel octane. There are not many "cases" related with octain value but they exist and main problem is engine starting not performance so give it a shoot you gone loose few Eur on fuel
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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 14, 2021, 04:17:36 PM »@Henry, even ECUs part numbers aren't the same, IF connectors fit each other, I would give it a go.
He can try swap ECU only if DT350 is Euro 3, because Euro 4 have EVAP system, he mention DT350 is 4 years old, It should be Euro 4
-if there would be an electronic fault, you would see a DTC on your diagnostic tool
It is more complicated then "dtc will pop out". In 15 years ECU diagnostic I have encountered many illogical problems and I can tell you ECU self-diagnosis is unreliable...very much!
@Henry
You must have O2 voltage cycling on idle when engine is warm, also when you hit throttle you should have spike to 0.9, and zero when you leave throttle (fuel cut off).. pls play with that little bit and write results here! Maybe it is clue for something...
Ruffus write very good check list, you should follow that!
My DT also stay all the time outside and I have habit once in year spray non water proof connectors with contact cleaner just for prevention!
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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 13, 2021, 07:08:34 PM »
ECU value are great!
Just one info, when engine is hot do you have O2 voltage cycling from 0.1 to 0.9?
You dont need to clean or check any sensor, not any more, you have perfect value...trouble is something else!
Take of fuel pump and ecu relay check for corrosion, also if relay looks clear, change that two relay with high and low beam (those two works fine I assume).....then test hot start! Check manual for relay location, if you cant, I can post it!
Weird fact is you have 2 same issue with 2 scooters, there is possibility it is maybe, I said again maybe fuel problem. So after you check relay, you can try buy some fuel aditive for petrol engine. Im from Croatia and here is fuel very bad, so I can tell you from first hand, depends from gas station to gas station I can feel big difference when starting engine, and vibrations when I cruze at 5500rpm.
About battery voltage, yes It can make trouble with ECU, when cranking voltage drop to low and ECU goes crazy and can manifest in many ways. However you should have biggest voltage drop when you cold start at couple celsius.
We need check cople more thing before we conclude ECU problem.
Just one info, when engine is hot do you have O2 voltage cycling from 0.1 to 0.9?
You dont need to clean or check any sensor, not any more, you have perfect value...trouble is something else!
Take of fuel pump and ecu relay check for corrosion, also if relay looks clear, change that two relay with high and low beam (those two works fine I assume).....then test hot start! Check manual for relay location, if you cant, I can post it!
Weird fact is you have 2 same issue with 2 scooters, there is possibility it is maybe, I said again maybe fuel problem. So after you check relay, you can try buy some fuel aditive for petrol engine. Im from Croatia and here is fuel very bad, so I can tell you from first hand, depends from gas station to gas station I can feel big difference when starting engine, and vibrations when I cruze at 5500rpm.
About battery voltage, yes It can make trouble with ECU, when cranking voltage drop to low and ECU goes crazy and can manifest in many ways. However you should have biggest voltage drop when you cold start at couple celsius.
We need check cople more thing before we conclude ECU problem.
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Downtown 300 / Re: DT 300 - fail to start - TPS voltage value at 0 position ?
« on: December 11, 2021, 08:46:46 PM »
Hello,
You mentioned that you have a Fi diagnostic tool, check all the value as shown in the picture (diagnostic report).
Pay attention to the ignition timing and water temperature sensor when engine warm, and also reference voltage for O2 when engine is off (ignition on). You ask about O2 sensor behavior, when you turn on the engine, ECU works in open loop mode until the sensor heats up, that is why you have low voltage readings at start. When engine get warm up you should have O2 voltage cycling. Another very important thing, during the engine starting (cranking) ECU always work in open loop until starts so there is no way O2 sensor creates your warm start problems.
After you check everyting on list, we can move on
You mentioned that you have a Fi diagnostic tool, check all the value as shown in the picture (diagnostic report).
Pay attention to the ignition timing and water temperature sensor when engine warm, and also reference voltage for O2 when engine is off (ignition on). You ask about O2 sensor behavior, when you turn on the engine, ECU works in open loop mode until the sensor heats up, that is why you have low voltage readings at start. When engine get warm up you should have O2 voltage cycling. Another very important thing, during the engine starting (cranking) ECU always work in open loop until starts so there is no way O2 sensor creates your warm start problems.
After you check everyting on list, we can move on
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