[barnett468]

Hello

My bike is instantly loading up the 2 right side spark plugs with excess fuel. It is the stock CFI injection. I'm guessing that either the fuel injectors are leaking or the computer is bad.

Any idea what might cause this?

Any idea how to test the injectors or computer to determine what the cause is?

Thanks for any help

 

[RambozoClown]

Swap the injectors Left/Right and see where the problem goes.

 

[barnett468]

Swap the injectors Left/Right and see where the problem goes.

Swap the injectors Left/Right and see where the problem goes.

Swap the injectors Left/Right and see where the problem goes.

Xlnt idea, however, I was hoping there might be a simpler way to determine if it is the injectors instead of the computer instead of dismantling half my bike to get to them, however, I do have a sawzall to simplify the removal of the fairing!.

 

[barnett468]

Xlnt idea, however, I was hoping there might be a simpler way to determine if it is the injectors instead of the computer instead of dismantling half my bike to get to them, however, I do have a sawzall to simplify the removal of the fairing!.

if the injectors are leaking is there a way to fix them or are affordable ones available?

 

[RambozoClown]

There are simpler ways if you have the right equipment. Injector leakage and flow test, and injector signal measurements would tell you a lot with minimal connections.

 

[DaveO430]

Check the vacuum hose to the Pb sensor near the top of the frame above the engine.

 

[barnett468]

There are simpler ways if you have the right equipment. Injector leakage and flow test, and injector signal measurements would tell you a lot with minimal connections.

There are simpler ways if you have the right equipment. Injector leakage and flow test, and injector signal measurements would tell you a lot with minimal connections.

unfortunately i dont have that.

Do you know if the main fairing has to be removed to access the injectors?

Also, if the injectors are bad are there replacements or a way to repair them, because if there isn't then there is no point taking it apart.

 

[barnett468]

Check the vacuum hose to the Pb sensor near the top of the frame above the engine.

what is a pb sensor and what does it look like and what do i have to disassemble to get to it?

what does the pb sensor do?

is there a separate hose to the left side and one to the right side injectors?

if there are not separate hoses, it would seem that this could not be the problem since only 2 injectors are a problem.

thanks

 

[DaveO430]

The Pb sensors are vacuum sensors, 1 on each side, each with a separate vacuum line. They sense the vacuum in the intake to tell the computer how long to open the injectors, if the vacuum is low as in a broken vacuum line it tells the computer to send more fuel to those cylinders. You have to remove the false tank to get to them.

 

[barnett468]

The Pb sensors are vacuum sensors, 1 on each side, each with a separate vacuum line. They sense the vacuum in the intake to tell the computer how long to open the injectors, if the vacuum is low as in a broken vacuum line it tells the computer to send more fuel to those cylinders. You have to remove the false tank to get to them.

The Pb sensors are vacuum sensors, 1 on each side, each with a separate vacuum line. They sense the vacuum in the intake to tell the computer how long to open the injectors, if the vacuum is low as in a broken vacuum line it tells the computer to send more fuel to those cylinders. You have to remove the false tank to get to them.

xlnt, thanks very much, i can do that, and that sounds the most plausible cause.

will i see a vacuum line coming from the injectors up to the sensor so i can identify the sensor, otherwise how will i know the sensors when i see them?

also, does the front fairing need to be removed to remove the fuel injectors?

thanks

 

[DaveO430]

xlnt, thanks very much, i can do that, and that sounds the most plausible cause.

will i see a vacuum line coming from the injectors up to the sensor so i can identify the sensor, otherwise how will i know the sensors when i see them?

also, does the front fairing need to be removed to remove the fuel injectors?

thanks

Yes you will see a vacuum line going to them. No, you do not have to remove the fairing.

 

[barnett468]

Yes you will see a vacuum line going to them. No, you do not have to remove the fairing.

Well I just looked on youtube to see how to remove the false tank to see the vacuum lines for the injectors, and it is easy to remove UNLESS the bike has an air pump like mine does.

Is there any easier way to tell if the right side vacuum line to the injectors is bad?

Exactly what needs to be removed to be able to remove the injectors if needed, and is there step by step instructions anywhere explaining how to remove these pieces to access the injectors?

Thanks again.

 

[DaveO430]

Here is a shot from the service manual. The vacuum line is not to the injectors, if you find the hose is leaking you shouldn't have to remove the injectors, they seldom go bad anyway.

 

[barnett468]

Here is a shot from the service manual. The vacuum line is not to the injectors, if you find the hose is leaking you shouldn't have to remove the injectors, they seldom go bad anyway. View attachment 329771

Thanks for the reply, however in your previous post, your comment implied that the vacuum hose goes to the injectors and now you say it does not, plus you didn't answer any of the questions I asked, so none of the info in the manual will help me unless I first know exactly how to access the areas in the photo, which appears to me to be the injectors.

 

[DaveO430]

Thanks for the reply, however in your previous post, your comment implied that the vacuum hose goes to the injectors and now you say it does not

I implied no such thing. I'll let someone else help you.

 

[Rednaxs60]

Hello

My bike is instantly loading up the 2 right side spark plugs with excess fuel. It is the stock CFI injection. I'm guessing that either the fuel injectors are leaking or the computer is bad.

Any idea what might cause this?

Any idea how to test the injectors or computer to determine what the cause is?

Thanks for any help

I'll chime in here. First, do you have the manuals needed for your bike. These are the OEM service manual, Electrical troubleshooting manual, and the supplement - this is the real important one. Without it you are going to ask a lot of questions and get a lot of opinion.

Loading up the spark plugs. Have you adjusted the idle on your bike at any time and if so, which screw did you use? There are two screws that can be used, but only one is specifically for the idle - located in the centre rear of the air chamber. The other is to balance the right left cylinder banks located behind the right CFI cover and is not to be used to adjust engine idle.

If you use the screw for the cylinder bank balance adjustment to adjust the engine idle, you will affect the fuel to the cylinders. This screw should only be adjusted when you have vacuum gauges connected to each cylinder bank. The engine idle will have to be adjusted as well if you change the engine cylinder bank adjustment.

The PB sensors should not affect your issue.

There are aftermarket injectors that can be used but must be low impedence injectors - 3.0 ohm or less. Injectors for an early model Civic/Prelude - 1985 will do.

ECU will affect fuel to the cyclinders, but primarily because of the TPS setting. Calibration too high, excess fuel used. Calibration too low, lean condition.

Good luck.

Are there any error codes on the ECU? These ECU are very robust and don't fail too often.

 

[barnett468]

I'll chime in here. First, do you have the manuals needed for your bike. These are the OEM service manual, Electrical troubleshooting manual, and the supplement - this is the real important one. Without it you are going to ask a lot of questions and get a lot of opinion.

Loading up the spark plugs. Have you adjusted the idle on your bike at any time and if so, which screw did you use? There are two screws that can be used, but only one is specifically for the idle - located in the centre rear of the air chamber. The other is to balance the right left cylinder banks located behind the right CFI cover and is not to be used to adjust engine idle.

If you use the screw for the cylinder bank balance adjustment to adjust the engine idle, you will affect the fuel to the cylinders. This screw should only be adjusted when you have vacuum gauges connected to each cylinder bank. The engine idle will have to be adjusted as well if you change the engine cylinder bank adjustment.

The PB sensors should not affect your issue.

There are aftermarket injectors that can be used but must be low impedence injectors - 3.0 ohm or less. Injectors for an early model Civic/Prelude - 1985 will do.

ECU will affect fuel to the cyclinders, but primarily because of the TPS setting. Calibration too high, excess fuel used. Calibration too low, lean condition.

Good luck.

Are there any error codes on the ECU? The ECU are very robust and don't fail too often.

Thanks very much for the reply.

1. I do not have any manuals other than what is available online.

2. Have not adjusted the idle, but I did read to see which screw was for the idle and which one was for the carb sync. Thanks for that info though.

3. Exactly what is a PB sensor and what are the vacuum hoses for that go to it?

3. a. Are you saying that the injectors will not over fuel the engine if the vacuum hose to the PB sensor/sensors, is leaking?

4. I did read on either this site or another site about which automotive injectors will work, and thanks for that info.

5. It is only over fueling the 2 right cylinders. Is the ECU split inside so that if one part of it goes bad it can over fuel the cylinders on one side or the other?

6. I had no idea there was a way to check for error codes and have no idea how to do that.

It is flooding both right cylinders the exact amount, which made me think that the problem was in something that controlled both right side fuel injectors independently from the left ones, instead of both fuel injectors failing at the same time.

I have been a vintage auto and motorcycle mechanic for over 40 years, and I also a high performance engine builder and tuner, and have jetted over 2,000 carburetors, but I know very little about fuel injection and computers or electronic control modules of any type.

.

 

[barnett468]

...in your previous post, your comment implied that the vacuum hose goes to the injectors and now you say it does not...

I implied no such thing. I'll let someone else help you.

ummm... You most certainly did as can plainly be seen in the quotes below.

Me

"will i see a vacuum line coming from the injectors up to the sensor..."

You

"Yes you will see a vacuum line going to them."

My question was very specific, and was not vague or ambiguous whatsoever, and your reply to my very specific question was YES.

 

[AZgl1800]

=> barnett468 said <=
Thanks very much for the reply.

1. I do not have any manuals other than what is available online.
===============================

so, what did you do with the manuals that I sent to you?

 

[barnett468]

...in your previous post, your comment implied that the vacuum hose goes to the injectors and now you say it does not...

=> barnett468 said <=
Thanks very much for the reply.

1. I do not have any manuals other than what is available online.
===============================

so, what did you do with the manuals that I sent to you?

I have everything you sent me, I meant that I don't have any original manuals in my hand. Sorry if my answer was confusing.

PS - When I say over fueling or flooding etc, I mean hurling fuel into the cylinders like the biblical flood. It will turn 2 brand new plugs as black as night with a heavy coat of carbon in around 2 - 3 minutes.

Compression is 150 in every cylinder with the throttle wide open. Initial compression after 1 engine rotation is around 60 in each cylinder, so the compression is good.
.