RX3 with Delphi EFI - Starting Issue

[uraki]

Hello

This issue has developed over time and now its severity has increased.
At the beginning the bike wouldn't start with only the self start button as always and i had to pump a little throttle. With time the morning cold starts were more and more difficult and black smoke would come out on 1st few engine cycles with smell of fuel. I checked and cleaned the air filter, my mechanic suggested to clean O2 sensor so I did that too by dipping it in petrol overnight and the installing it. The throttle body was cleaned along with injector and this brought the problem back to a milder state but not resolved.

Now again after 2 weeks or so the problem has intensified. So I started with code display (ON OFF ON OFF ON) but that didn't work. No codes. I opened the spark plug and it was black and wet with fuel. I removed cable from coil directly touching it on tip of spark plug and found out that no spark is jumping from the coil. Meanwhile, i tried the ignition coil & cable from another rx3 but that didn't work either. Whereas the ignition coil & cable removed from my bike worked fine on the other rx3. So I turned my attention to fuel accumulating in the combustion chamber.

Then I had an idea. I tried disconnecting the fuel pump connector beneath the tank and tried to get the bike started by cranking the self starter. And it worked the bike started for 3 seconds and then due to fuel pump disconnected it was shut off. I didn't turn the kill switch off and on which would cause the engine check to run and connected the pump connector, cranked the self starter and the bike started on 1st self.

Now every time i turn on the kill switch when fuel pump is connected, the bike does not start. But if i disconnect fuel pump and crank a few time the excess fuel in the combustion chamber is gone and after connecting fuel pump the bike starts on next self start provided i didn't turn the kill switch off and on.
The code that is displayed is 0230 on the MIL (10 blinks, 2blinks, 3blinks, 10blinks) related to FPR Coil Circuit Low Voltage of Open.
After the bike was started, i fixed the seat and took it for around 40 to 45 km ride. It went smoothly, no missing, no stalling, zero issues at all. But when it comes to starting, the bike refuses to start as there is too much fuel being injected in the chamber which makes the spark plug wet.

[uraki]

I would like some expert advice on the course of action to take in order to resolve this issue.

Thanks

[bogieboy]

sounds like the injector may be leaking down overnight? or you may have a fuel pressure regulator issue allowing too much fuel at the startup due to over pressure, and once the bike is running, it can compensate with the O2 sensor to combat the extra fuel?

[NzBrakelathes]

better do some live data reading - what is the injector pulse whhile starting and once it starts?

[uraki]

Update:

This morning I opened the injector, inspected the injector for any leaks when the pump is but it was okay. I also checked the pulses when self start is pressed and the injector was spraying fuel in atomized form which looked OK to me. Unfortunately I don't have the diagnostic setup with me right now so couldn't do anything else. I cleaned the injector with carb cleaner from both sides and installed it back.

Then I opened the IAC stepper motor and it had carbon residue in a considerable amount but not too much to be an issue. But I cleaned it thoroughly anyways.
For now i didn't open the complete throttle body but just sprayed carb cleaner in through the IAC hole and after it was dried I installed the IAC back in place.

As I had not removed the tank completely and was working with all the lines attached. I noticed that when I sprayed carb cleaner thru the IAC hole it caused the fuel to start coming out of drain point of the assembly between the battery and exhaust pipe (don't know what it is called). There is a tank line and a purge line on it coming from tank and MAP respectively. So i made necessary adjustments to stop the fuel from draining and then closed everything.

After this activity the bike is starting and the problem seems resolved. It is strange but I don't know exactly what happened!! Was there some blockage which was released and now the air flow is normal?

[Jay In Milpitas]

You did very well in tracking your problem! It does seem there was obstruction in the Idle Air Control port. The only information missing now is what the blockage was and what caused it.

I admit being confused what adjustments you made to stop the fuel from draining, but not going to fret over it.

Out of curiosity, how many miles on your RX3?

Jay

Originally Posted by uraki

Update:

This morning I opened the injector, inspected the injector for any leaks when the pump is but it was okay. I also checked the pulses when self start is pressed and the injector was spraying fuel in atomized form which looked OK to me. Unfortunately I don't have the diagnostic setup with me right now so couldn't do anything else. I cleaned the injector with carb cleaner from both sides and installed it back.

Then I opened the IAC stepper motor and it had carbon residue in a considerable amount but not too much to be an issue. But I cleaned it thoroughly anyways.
For now i didn't open the complete throttle body but just sprayed carb cleaner in through the IAC hole and after it was dried I installed the IAC back in place.

As I had not removed the tank completely and was working with all the lines attached. I noticed that when I sprayed carb cleaner thru the IAC hole it caused the fuel to start coming out of drain point of the assembly between the battery and exhaust pipe (don't know what it is called). There is a tank line and a purge line on it coming from tank and MAP respectively. So i made necessary adjustments to stop the fuel from draining and then closed everything.

After this activity the bike is starting and the problem seems resolved. It is strange but I don't know exactly what happened!! Was there some blockage which was released and now the air flow is normal?

[NzBrakelathes]

Originally Posted by Jay In Milpitas

You did very well in tracking your problem! It does seem there was obstruction in the Idle Air Control port. The only information missing now is what the blockage was and what caused it.

I admit being confused what adjustments you made to stop the fuel from draining, but not going to fret over it.

Out of curiosity, how many miles on your RX3?

Jay

they get dirty very common - possibly air filter material or unclean air filter too

[uraki]

7500km on my bike

Originally Posted by Jay In Milpitas

You did very well in tracking your problem! It does seem there was obstruction in the Idle Air Control port. The only information missing now is what the blockage was and what caused it.

I admit being confused what adjustments you made to stop the fuel from draining, but not going to fret over it.

Out of curiosity, how many miles on your RX3?

Jay

[NzBrakelathes]

Maybe AIC valve dirty n too open or closed messing with parameters
Reset ecu also turn key on then off 5 cycles wait 15 seconds then key on n start

[uraki]

Okay coming back after a little while.

The problem was resolved only for a day and came back the next morning on cold start since then I have been working off and on and following is the summary of it.

After checking other things, I concentrated more on fuel side and as mentioned earlier with ignition ON the fuel pump stays ON longer than usual (about 5 sec). I disconnected the wire on the fuel pump below the tank and then tried to start. The bike started and as there was no supply of the fuel it died. Then on next try I connected the fuel pump but this time bike did not start.

After several tries I connected ON/OFF switch on the fuel pump connector and now when i have to start the bike I just turn the fuel pump OFF and the bike starts. Then I turn ON the fuel pump and it keeps on running.

So the problem is that at the start or ignition ON stage the engine is getting flooded with fuel somehow because of the pump and when the pump is OFF the little fuel present in the engine is enough for starting the bike. This happens every time now, no matter if engine is hot or cold.