Injector pulse Pin 17

[flyingbrick242]

Symptom: Back feed through injector circuit causing green INJ/IDC and Red "sys on" led to stay illuminated all the time after starting engine. Shutting off while pump and system still spraying and both leds still illuminated. It will stop when disconnecting pulse signal.

Background: Sequential injection, pin 17 tapped into pulse signal of # 5 injector.

Engine: 2004 Volvo B5254T with ME7 Bosch fuel injection.

Any help would be appreciated.
Thank You. :D

[Richard L]

In future, please post aquamist relatived problems to the aquamist section., I don't always visit every forums on thsi site.

I need to know a few things first:

1. Which aquamist system do you have.
2. What version of the DDS3 junction board.
3.Serial number of the flow sensor.
4. Do you have a wiring diagram of the ECU pin you can post here?

I think there is a wiring problem. But I need the above anwsers to be certain.

[flyingbrick242]

My appologies to submitting in wrong section.

1-HFS-5
2-DDS-3 V10
3-Flow sensor serial# 3884
4-Sorry but No ECU wiring but can tell you its a typical ground pulse signal.

Let me know what other information you need .
Thank You

[Richard L]

OK, I have just had a chat with Jeff Howerton.

Your system is now basicalluy working as it shoudl apart from the injector pulse pick.

Lets work on this now:

1. Please disconenct the wirung that oyu splice into fuel injector's pulse leg.
2. Start the car
3. Does the resd and green led trigger?
4. With the engine still running.
5. Manually stabbing the injector pulse "pick up" wire to ground (from pin17 pg fthe juction box)
5. Tell me if this triggers the red and green led.

We stop at this stage and wait for your results.

[flyingbrick242]

Pulse lead disconnected engine running NO green led or red led.
While engine is running take pin 17 to ground green led is on including red led and pump stats to operate.

[Richard L]

This sounded like the pin 17 is picking up the wrong injector pulse signal. The system appeared to be working as it should.

OK, lets go a bit further....

1. Where are you picking up the "injector pulse" signal? Is it from the actural injector or ECU?
2. What type of fuel injector is it? 16 ohm, 10 ohm of 2.5 ohm?
3. Does the injector use a "resistror pack"?
4. Did you splice the wire from the ECU or at the fuel injector harness.
5. Important: Where are you picking up the 12V supply to the DSS3 junction board (pin24).

[flyingbrick242]

The injector- I made up connectors to splice in between

12 ohm injector

No resister pack

Right at the injector harness

Directly into the fuse box which is only powered when in pos II and cranking.

[Richard L]

Everything looks perfect.

1. Can you measure the voltage of the 12V wire from the fuse box at idle. (DDS3 pin24)
2. Can youi measure the volatge at pin 17 when the engine is at idle. (DDS3-pin17) with the green wire spliced into the inj(-).

All relative to a known good ground.

[flyingbrick242]

Pin 24 at idle 14.2v

Pin 17

Injector pulse disconnected 13.3v
Injector pulse connected 11.2v

[Richard L]

Pin 24 at idle 14.2v

Pin 17

Injector pulse disconnected 13.3v
Injector pulse connected 11.2v

I think we might have discovered the problem. The differecne of voltage between pin 24 and pin 17 is outside our designed limits. There seem to be a dropof 0.9V between the two points. The design limit is 0.45V.

The best way to over comthis is by taking the 12V from the fuel injection +ve. (powering the DDs3's pin24). This way you willnot get the false trigger.

If you have time to look into this closely, check at each point of the electrical function between the Battery+ to the Injectot (+):

Battery -> FI relay -> Fuse -> fuel injector + , somewhere along this line, there is a high resistance junction. Or possibly the wire gauge is too thin. Another possibility is the fuel pump is load up the same supply anf drop it from 14.2V down to 13.3.

Alternatively, I can modify the v10 to suit your car. Either way, Try the first suggestion.

[flyingbrick242]

Richard,

If I am following your thoughts:

1-Check for voltage drops between inj+ and fusebox +, this difference might be highier then your limit allows.

2-Take the +12v from the fusebox currently powering up my DDS3 and connect it to my fuel injection ecu switched power.
Is this correct?
Thank You

[flyingbrick242]

Richard,

If I am following your thoughts:

1-Check for voltage drops between inj+ and fusebox +, this difference might be highier then your limit allows.

2-Take the +12v from the fusebox currently powering up my DDS3 and connect it to my fuel injection ecu switched power.
Is this correct?
Thank You

Richard,

Update to above.

There is a 1.2 voltage drop between the +injector signal from ecu and fusebox cable pin 24
Will there be any advantage taking +15 or switched key voltage from ecu to correct this concern??
It looks like we are too far apart from your desired threshold.
What are your thoughts?
Thank You for your support.

[Richard L]

Richard,

If I am following your thoughts:

1-Check for voltage drops between inj+ and fusebox +, this difference might be highier then your limit allows.

2-Take the +12v from the fusebox currently powering up my DDS3 and connect it to my fuel injection ecu switched power.
Is this correct?
Thank You

Richard,

Update to above.

There is a 1.2 voltage drop between the +injector signal from ecu and fusebox cable pin 24
Will there be any advantage taking +15 or switched key voltage from ecu to correct this concern??
It looks like we are too far apart from your desired threshold.
What are your thoughts?
Thank You for your support.


Basically, it will work well if you move the DDS3 power in to the fuel injector +. This way, the difference will be much cloaser to each other.

I can modify the DDS3 for you to allow the bigger volatge drop at your injector. At present it is 0.5V but I increase it to 5-6V. No rcharge, just need you to send the DDS3 Junction board back to me.

[flyingbrick242]

Richard,

It will be very simple for me to tap into the +feed for the injector and see what results occur.

Question and concern:: What is the power consumtion of the DDS3 box?
My concern will there be too much taken from the + signal of injector and ecu.
Please Advise.

[Richard L]

Richard,

It will be very simple for me to tap into the +feed for the injector and see what results occur.

Question and concern:: What is the power consumtion of the DDS3 box?
My concern will there be too much taken from the + signal of injector and ecu.
Please Advise.

The DDS3 draw about 100-250mA (low to full backlight intensity) to 1.2A when the HSV is at full flow. You can always run a separate +12V to the HSV.

[flyingbrick242]

Richard,

I have rewired the +12v for the dds3 directly off of the ecu power up supply and have the following observation:

1-The flow gage has a hard time to start up, the illumination is flickering then a few seconds later gage is running.
2- The inj/idc led is lit up all the time.
3-When trying to run test mode the flow gage shuts on and off with no flow meter working.
Yellow led is on all the time.
Please advise.

[Richard L]

By moving the DDS3 12V source to the injector supply rail, the start-up timer will be interfered with by a large amount of spike and quiet a bit of noise ripples.

I think we can solve this problem by sendng you a modified v10 board and upon receiving and successful install, return the board to us by USPS in your own time.

I therefore need your postal address by pm. I will airmail you a v10 tomorrow.

Richard

[flyingbrick242]

PM has been sent

[Richard L]

Just a matter of interest, did the person who you bought the system from had this problem?

[flyingbrick242]

Just a matter of interest, did the person who you bought the system from had this problem?

He claims NO.....and I would have to believe this since it was about 1,5 months ago when he had purchased it.

[Richard L]

I suppose the he may not have the voltage variation on his car. It does not matter anymore, will solve the problem by changing the configuration a bit.