P700 no signal to fuel injector

[onesparkplug]

Hi sent a message to the wrong place a minute ago .so here goes long story short ..my 2009 big red quit on me a few days ago ...found good spark ..good fuel pressure, sounds normal cranking, but wont fire up ...if i spray gas into the throttle body she fires up for a second...so hence ,no fuel coming out the injector( I think) put a noid light on the connector wire ..saw no flashing power light ...however did confirm 12 v to one wire cpk was changed a while back by honda the recall.....do these get a ground signal to complete the injector spray?....or?.....next step is the pull injector and confirm no fuel cranking...any help would be nice Theresa

 

[Admin]

 

[DG Rider]

Hi sent a message to the wrong place a minute ago .so here goes long story short ..my 2009 big red quit on me a few days ago ...found good spark ..good fuel pressure, sounds normal cranking, but wont fire up ...if i spray gas into the throttle body she fires up for a second...so hence ,no fuel coming out the injector( I think) put a noid light on the connector wire ..saw no flashing power light ...however did confirm 12 v to one wire cpk was changed a while back by honda the recall.....do these get a ground signal to complete the injector spray?....or?.....next step is the pull injector and confirm no fuel cranking...any help would be nice Theresa

Usually the injector is grounded to fire it.
Check: All the wiring to the injector and CKP sensor.
Also: There may be a "system" or "FI" relay and or fuses. Check them.

Do you have a factory service manual? This would be like flying blind to try and figure out without one. You may even find one on the internet to be downloaded for free.

 

[DG Rider]

Disregard my injector firing comment. I looked at the 700 Pioneers wiring diagram, and it does indeed look like they are fired from the power side, so the big red almost certainly is as well.

 

[onesparkplug]

Disregard my injector firing comment. I looked at the 700 Pioneers wiring diagram, and it does indeed look like they are fired from the power side, so the big red almost certainly is as well.

.Thank you ...could the crank sensor do the fire?...just a thought ..going to do a ohms test asap . big red is in az i work in cali

 

[DG Rider]

.Thank you ...could the crank sensor do the fire?...just a thought ..going to do a ohms test asap . big red is in az i work in cali

Yes. The ECM uses the signal from the CKP to know when to fire the injector (and the plug, for that matter). You should also hear the fuel pump start running again while cranking, though that might be tough over the sound of the starter.

BUT...that fact that it runs while spraying fuel in it means the CKP/Spark event is working. I Should have pointed that out earlier.

 

[DG Rider]

Try this for a service manual download:Big Red Service Manual 2009-2012. Divided downloads.

Unfortunately, it looks like a low res scan, so the wiring diagrams are hard to read, but it may help.

 

[onesparkplug]

Thank you very helpful...the only thing that threw my off was the fact that when i put my noid, test light on ii it never showed a light ..but there is power to one wire...and thinking it gets a ground signal to fire it ....do you think its a steady spray or pulsing like bosch injection?....T......

 

[DG Rider]

Thank you very helpful...the only thing that threw my off was the fact that when i put my noid, test light on ii it never showed a light ..but there is power to one wire...and thinking it gets a ground signal to fire it ....do you think its a steady spray or pulsing like bosch injection?....T......

Its a pulse, though at higher RPM it may look like a constant spray.

How did you find power to the injector? Test light hooked to ground?

 

[onesparkplug]

Its a pulse, though at higher RPM it may look like a constant spray.

How did you find power to the injector? Test light hooked to ground?

. Yes simple test probe light.

 

[DG Rider]

OK...ok....my next advice is to stop listening to me!!!

Forgive me...its been a while since i've done electrical troubleshooting, so i am rusty. BUT, going back and looking at the 700 Pioneers diagram, what i thought was a ground was actually a power side splice (leading to a few sensors, etc), and BOTH injector wires lead back to the ECM, so it most likely does fire by grounding, as my original instincts told me.
I wish that BR manual had better pics to see wire colors.

 

[onesparkplug]

HI DG .........been away from the big red for a while ...got fed up.actually live 200 miles away... the guy that sold it to me 2 weeks ago says it always ran ...maybe but .....I got 1 mile down the road. from forking out thousands in cash. and barley made it to my place ..I trusted my fellow american ...now back to it ....the fact that the plug fires while cranking ....does that mean the ckp is perfect?...maybe a secondary signal for the injector?....Thanks Theresa....

 

[DG Rider]

HI DG .........been away from the big red for a while ...got fed up.actually live 200 miles away... the guy that sold it to me 2 weeks ago says it always ran ...maybe but .....I got 1 mile down the road. from forking out thousands in cash. and barley made it to my place ..I trusted my fellow american ...now back to it ....the fact that the plug fires while cranking ....does that mean the ckp is perfect?...maybe a secondary signal for the injector?....Thanks Theresa....

To me the fact that it ran while you supply fuel tells me that the ckp is okay.

You said you had power to one side of the injector, correct? The next step to me would be to check continuity from the other side of the injector... The ground side, back to the PGM fi connector ( the computer). That service manual may have the PIN numbers for this somewhere in it.
Look in the trouble codes section for injector codes and tests.
And speaking of DTC's, is your check engine light staying on while cranking or flashing? That code might be a good clue as to what's going on. The manual should tell you how to pull those as well.

In the meantime let's get somebody who works on these daily involved here:
@HondaTech , you got anything?

 

[70Bones]

Hi Theresa, I'll echo much of what DG has written above.

I have the Pioneer 700 wiring diagram, not the Big Red diagram, and the fuel injector and ignition coil both get the same positive voltage signal. The negative for each is provided through the PCM, which cycles them both, as per DG Rider, so the CKP must be fine.

The two wires on the injector, on the P700, are red/black (+12v when the key is turned on) and green/white, which goes directly to the PCM for switching. If the wire colours are the same, maybe the PCM is the same? This is way out there, but the green/white wire goes from the injector connector directly to B33 on the PCM.

To me is looks like the green/white wire is broken... or the PCM isn't switching it.

Just so I'm clear, your noid light is not flashing when hooked to the injector connector and the engine is cranking?

 

[Neohio]

If noid light isn't lighting, try reversing it in the connector.
I haven't used one in a bit, and I don't remember if they are polarity sensitive.

 

[onesparkplug]

Hi Theresa, I'll echo much of what DG has written above.

I have the Pioneer 700 wiring diagram, not the Big Red diagram, and the fuel injector and ignition coil both get the same positive voltage signal. The negative for each is provided through the PCM, which cycles them both, as per DG Rider, so the CKP must be fine.

The two wires on the injector, on the P700, are red/black (+12v when the key is turned on) and green/white, which goes directly to the PCM for switching. If the wire colours are the same, maybe the PCM is the same? This is way out there, but the green/white wire goes from the injector connector directly to B33 on the PCM.

To me is looks like the green/white wire is broken... or the PCM isn't switching it.

Just so I'm clear, your noid light is not flashing when hooked to the injector connector and the engine is cranking?

Hi yes no flashing ...but power to one wire,red thank you sounds good, ill trace the grn wire back to the pcm....tht will be maybe fri or sat, have to work till then ..Theresa ps Bendix Magnetos still use points and condenser ,and rarely fail ...love that technology

 

[onesparkplug]

Hi Theresa, I'll echo much of what DG has written above.

I have the Pioneer 700 wiring diagram, not the Big Red diagram, and the fuel injector and ignition coil both get the same positive voltage signal. The negative for each is provided through the PCM, which cycles them both, as per DG Rider, so the CKP must be fine.

The two wires on the injector, on the P700, are red/black (+12v when the key is turned on) and green/white, which goes directly to the PCM for switching. If the wire colours are the same, maybe the PCM is the same? This is way out there, but the green/white wire goes from the injector connector directly to B33 on the PCM.

To me is looks like the green/white wire is broken... or the PCM isn't switching it.

Just so I'm clear, your noid light is not flashing when hooked to the injector connector and the engine is cranking?

Thank you for the reply .....will trace an open in the green wire asap Theresa..PS...noid light not flashing

 

[70Bones]

Hi yes no flashing ...but power to one wire,red thank you sounds good, ill trace the grn wire back to the pcm....tht will be maybe fri or sat, have to work till then ..Theresa ps Bendix Magnetos still use points and condenser ,and rarely fail ...love that technology

lol, yup, the magnetos, points and condensers did the job for many years. Hope they're not still in service in those airplanes!!!

 

[onesparkplug]

lol, yup, the magnetos, points and condensers did the job for many years. Hope they're not still in service in those airplanes!!!

Hi .. yes,, Cessna, piper, mooney etc still use points ...slick mags also ...so easy and reliable....T

 

[onesparkplug]

If noid light isn't lighting, try reversing it in the connector.
I haven't used one in a bit, and I don't remember if they are polarity sensitive.

Hi ill try that ...Thanks T

 

[70Bones]

Did you get a chance to work on the Big Red? Any luck?