Datsun 1600 HFS3-Help needed

[Fit Buddy]

Hey guys,
I have a Datsun 1600 fitted with an FJ20DET. The engine is controlled by an Autronic SM4 and CDI 500 units. After discovering your website and doing some research , I decided that the HFS3 would best suit my upgrade needs.
I have recently purchased and installed the Aquamist HFS3 system in my car. Tonight, while going through power up and testing of the system, I have experienced a few problems. I am using FIDC as the trigger. Steps 1-4 of the power up procedure was successful. After connecting the rest of the harnesses, I attempted to proceed with the manual testing. This is where my problems began. With all the harnesses connected and the ignition turn on to pre-cranking, the system began spraying as soon as it was turned on.The green, amber and red LEDs are also illuminated when the ignition is turned to the pre-crank position.
I disconnect the harnesses and double checked all my wiring. Everything seemed as it should be so I reconnected it all. It did the same thing again so I turn ever thing off and went through the manual again to see it I had missed anything. I came back about 30 mins later and turned the ignition to the pre crank position. The green, amber and red LEDs were again illuminated but this time only the water level LED on the gauge lights up even when the gauge is turned on. I have double checked all the wires and everything look fine.
If anyone call assist me to sort this problem out and get my system working correctly it would be much appreciated.
Thanks, and kind regards,
Orlando

[Fit Buddy]

Below is a photo on the unit when the ignition is turn to the pre-cranking position:

http://i1222.photobucket.com/albums/dd496/FitBuddy/car/015.jpg

Below is a photo of the gauge when its switched on and the ignition is turn to the pre-cranking position:

http://i1222.photobucket.com/albums/dd496/FitBuddy/car/018.jpg

A few photos of my car:

http://i1222.photobucket.com/albums/dd496/FitBuddy/car/09032007143.jpg

http://i1222.photobucket.com/albums/dd496/FitBuddy/car/001.jpg

http://i1222.photobucket.com/albums/dd496/FitBuddy/car/036.jpg
The water tank hold 17 litres and has good internal baffling. Probably overkill but great piece of mind.

http://i1222.photobucket.com/albums/dd496/FitBuddy/car/022.jpg
Fav mounted in the engine bay. All plumbed up and ready for testing.

[Richard L]

can you remove the green wire of the grey connector from the fuel injector and let me know if the system still turns at "pre-crank" position.

We will take this one step at a time. Very nice install BTW!

[Fit Buddy]

Thanks Richard. I really appreciate you taking the time to assist me. I have been taking my time with this install as i wanted to do it right the first time.

I did as you suggested and disconnected the green wire running to the fuel injector and turned the ignition to the pre-crank position. Non of the 3 LEDs in the control module were illuminated. The gauge was turned on and stayed the same as you see in the picture.

[Richard L]

In this case, there must be some mis-matching of the voltage level of the fuel injector that prematurely triggering the system.

The injector (-) should be the same voltage level as the injector (+) at the pre-crank position. Can you re-locate the red wire of the grey connector to fuel injector (+) and let me know this problem is overcome. Note: provided this is no resistor pack on the (+) leg of the fuel injector.

If you have a spare PWM channel on your ECU, you can create your own WI map.

[Fit Buddy]

I had it set up that way initially with the (+) and (-) voltages from injector number one. The system activated in the pre-crank position with this configuration. I then changed the (+) input to the computers ignition 12 volt supply after seeing it set up that way in a few of the wiring diagrams on this forum. In this configuration the system again activated in the pre-crank position once before it stopped working. Now all that happens is what you see in the photos.

[Richard L]

I remembered somer years ago one of our IDC based system has the same problem This due to the voltage on the injector (+12) is much lower than our designed window. The low voltage was caused by running a more power fuel pump on the same supply cable, loading up the circuit.

We solved this problem by extending the lower threshold voltage of the detection circuitry. We can try the same thing here. Are you confident doing some soldering?

Before we are do this please measure the voltage of test point 5, test pin 12 and test point 23 for me at (1) pre-crank position and (2)post-crank position.

[forrest]

WOW, this is really similar to the problem I'm having. You don't have racelogic do you? I just figured out that is contributing to my issues

[Fit Buddy]

Cheers Richard. I'm away until Wednesday so I'll try what you have suggested when I get back. Please excuse my ignorance but can you tell me where the 3 test pins are located and how to identify they as I am still learning my way around this system.

The ECU I'm using is an Autronic SM4. It does have a spare PWM output but I wouldn't know how configure it to the aquamist system.
I am confident with a soldering iron too.

[Richard L]

test pin/points are on top of the jumper links, all 30 of them.

I will the best way to modify the circuit your overcome your trigger problem after I have the infos..

[Fit Buddy]

Hey Richard,
The data you requested is listed below:

PIN - Pre Crank Voltage - Post Crank Voltage

1. 12.71 - 13.48
2. 0 - 0
3. 12.71 - 13.48
4. 4.50 - 0.06
5. 12.71 - 13.48
6. 0.54 - 0.55
7. 0.76 - 0.75
8. 0.02 - 13.48
9. 9.58 - 2.64
10. 0 - 0
11. 9.58 - 9.62
12. 12.02 - 13.48
13. 2.81 - 2.81
14. 0.24 - 0.18
15. 5.23 - 5.24
16. 5.60 - 0.08
17. 0 - 0
18. 4.95 - 0.07
19. 4.77 - 0
20. 2.38 - 2.32
21. 0.53 - 0.58
22. 2.40 - 2.40
23. 12.71 - 13.48
24. 0.01 - 0.01
25. 8.30 - 8.32
26. 4.64 - 4.65
27. 0 - 0
28. 2.57 - 2.57
29. 7.41 - 0
30. 0.88 - 0.76

[Richard L]

Thanks for the voltage, nice.

I can see the problem. Your 12V rail volatge is very low compared to a normal car. The H3 is comparing the rail voltage against the injector(-) voltage if it lower than 0.5V, it is considered as injector activation.

We have a few solutions:

1. Beefing up 12V cable size to the fuel pump and injectors. It is good practice anyway to have as little drop in voltage as possible.

2. Modifing the HFS-3 to allow a wider detection window. I think in your case, 2V is about correct.

I suggest doing solution #1 first, allowing the voltage on test pin#5 less than 0.5V.

[Fit Buddy]

Thanks Richard. I don’t yet fully grasp concept of how the H3 unit uses (+) and (-) voltage to trigger the system. As for the low rail voltage, is this pre or post cranking? My car has a pretty low idle. When I rev it up while taking the reading I saw over 14 volts at pins 5, 12 and 23.
Beefing up my fuel pump and injector cables poses a bit of a problem as it would require considerable modification to my wiring harness. I could possibly reduce the load been drawn by the fuel pumps by running them straight from the battery and using their current supply from the ECU to activate a relay. Would this solve the low rail voltage problem? If not the modifying the HFS-3 might be my only other option.
Cheers, Orlando

[Richard L]

Can you tell me the colour of the circuit board so that I can identify the version.

Let me a moment to work out the best way to tackle this.

Richard

[Richard L]

There is odd that you fuel injectior is not powered up at the pre-crank position.

Please re-locate the red wire of the grey connnector directly to fuel injector (+).

[Fit Buddy]

I?ll double check the circuit board when I get home and I?ll change the wire on the weekend.

Here is a quick recap of events so far:

(1) Installed HFS-3 unit. (+) and (-) input to unit both taken from injector number 2.
(2) Followed the start up guide to the letter. Everything worked as it should in this initial phase.
(3) Moved on to the system priming phase. Ignition to the pre crank position and gauge turned on. As soon as the delay passed and the gauge powered up the system activated and started spraying water.
(4) Tried several times, all with the same outcome. During the times the system was activated and spraying, the bar graph on the gauge never went past 2 bars. This was the same for both pre and post crank position.
(5)When away for a few weeks. Did some head scratching and some research while I was gone. Came Across and few wiring diagrams on this forum which showed the (+) input taken from the computer 12 volt ignition supply. So I changed mine to match that configuration when I came back.
(6) Gave the system a thorough going over. Powered it up and the same happened as I've explained at number 4.
(7) Left the gauge on and turned the ignition off and back on again. This time the gauge didn?t light up as it had done previously. The only light it displayed was the yellow water level LED. The system did not activate and hasn?t since.

[Fit Buddy]

The circuit board is black.

[Fit Buddy]

Richard, I'm not sure if it will help but just in case here is the link to the manual for my ECU. http://www.mrm-racing.se/bag/SM4MANUAL.pdf
The wiring diagram is on page 128. The only difference to the wiring on my car is that I now run the Autronics CDI unit. I'll see in I can find and wiring diagram for that too just incase.
Cheers, Orlando

[Fit Buddy]

CDI Info and wiring:
http://www.mrm-racing.se/bag/500R%20CDI%20Specifications%20Oct2009.pd f
http://www.mrm-racing.se/bag/DFCDI%20BASIC%20WIRING.pdf

[Richard L]

One step at a time...

Can you check the voltage at the injector(-) Pin#8 at pre-crank position. It should have 12V there.

According to the test voltages above, it showed near 0 volt!

[Fit Buddy]

Just tested it mate. The reading is 0.02 volts.

[Fit Buddy]

Hey Richard,

In following your instructions, I ran the (+) supply from the injector supply. In the pre crank position the LEDs in the control module no longer illuminate. In the post crank position the green LED flickers, increasing and decreasing as engine speed does. The water level light stayed illuminate in both pre and post crank position for about 5 mins then it went out. There is now no LEDs illuminated on the gauge in either pre or post crank position when the gauge is turned on or off.
I also re tested the voltage at pin 8 in both the pre and post crank position with the same results as before. As per the autronic wiring diagram, the source for the injector positive supply comes from the fuel pump relay. In the pre crank position, this circuit is energized for 5 seconds then cuts out as the engine isn't running. I test pin 8 voltage as so as the pre crank was selected and the reading was 12.81 volts until the circuit de-energized.

[Richard L]

Now I can see the problem.

It appears after 5 seconds, the (+) of the fuel injector drops out hence the HFS-3 turns off. Reason being the system will not spray accidentally if there is not (+) supply to the fuel inejctors.

If there is a switch between the +12V to the fuel injectors (+), the system will work properly without the 5-second timing turning the system off. Is it possible for you to disable this timer?

[Fit Buddy]

The timer circuit is a safety feature of the ECU to stop the fuel pump in case on an accident. I'm sure you already know this though. To disable the timer the injectors power supply has to be re-routed as per the Autronic's alternate wiring diagram. It doesnt look like a difficult job. I'll tackle it later on in the week when I have a little more spare time.
Thanks again for your help mate.

[Richard L]

I think it is a good idea to power up the fuel injector (+) with out powering up the fuel pump.

[Fit Buddy]

Ok mate. No probs. I should have that sorted by tomorrow evening. Is there anything you want me to check after I've made that change?

[Richard L]

I think this is the only change you need to make.

[Fit Buddy]

G'day Richard.
I tried rewiring the injector supply. My attempt was unsuccessful as contrary to the alternate wiring diagram, the system cannot work that way. I have since returned the ECU wiring to its original configuration. Both (+) and (-) signal to the Aquamist control module are taken from the injector. With the (+) and (-) signal taken from the injector, the LEDs in the control module no longer illuminate in the pre-crank position.
I understand that once the fuel pump relay de-energises in the pre-crank position the unit senses no power and switches off. I don't understand though why, in the post crank position when the engine is running and power is being supplied to the unit, the gauge doesn't turn on as it did on the first few occasions.

[Richard L]

So far this is the only time I have encountered the fuel injectora re not powered up (only 5 seconds) at the pre-crank position.

We insisted on the system will only turn on when there is 12V present at the fuel injector. This will avoid any accidental/pre-mature spray when the engine is not running.

At the post crank postion, I suspect the same reason, if the engine is not running, the ECU switches off the (+) supply to fuel pump and injectors.

[Fit Buddy]

Cheers Richard. All other things aside though, I still dont understand why when the car is running and power is being supplied to everything, the unit still doesnt function.

[Richard L]

If you don't mind taking the voltages agian for me. Without those information, it is difficult for me to know where the problem is. (with the engine running of course)

[Fit Buddy]

No probs mate, I'll get you those readings tomorrow.

[Richard L]

the most important pins are:

pin #5 ........ injector (+) This must have 12V there to power up the system.
pin #8 ........ injector (-) We retrieve the idc signal from here.

[Fit Buddy]

Hi Richard,

I apologise for not replying to your last post. I am in the Navy and had to crash sail. I have only recently returned and picked up where I had left off.

Over the past few weeks I have managed to get my car up and running again. After some modifications to the ECU wiring a few weekend ago, the Aquamist powered up as per the instruction manual. I then dropped the car of to my tuner and it was agreed that he would do the system test of the Aquamist and complete the tune.

This morning my turner rang and said that he was able the get the system to work in the “test” mode but the system does not trigger in the normal working mode when the 40% injector duty cycle trigger point is reached.

I was wondering if you have ever encountered this problem before and what the cause would be. If not would you have any suggestion on where to look for a likely cause to this problem noting the following:
1. The Aquamist inputs are the (+) and (-) supply from the injector as per the instruction manual
2. The system powers up fine and the F-IDC light increases and decreases with engine RPM.
3. Tank level is over ?
4. The system can be manually activated in “test” mode, where it performs as per the instruction manual.
5. My tuner has tried turning the threshold knob all the way anti clock wise and still no spray activation
6. The ecu data logger shows a peak injector duty cycle of 70%

Thanks Richard,

Kind regards,
POMT Orlando Barrett
HMAS Success Manager AAS
Level 3, Building 89/90
Garden Island

orlando.barrett@defence.gov.au
(tel) 02 9359 6167
(mob) 0418 315 466

[Richard L]

Good to know we have moved on a bit further.

To test if the system is reading the F-IDC or not, please do the folllowing:

1. Remnove jumper link "PRK"
2. put it on to "FDC"

Now the gauge will display the F-IDC on the gauge. Please let me know the result.

[Fit Buddy]

Hi Richard,

I did as you instructed and there was no change to the gauge other than the little red s disappearing.

[Richard L]

It appears the f-idc (injector-) is not getting into the circuit board

Please check the green wire of the grey connector is wired to the fuel injection(-).

Also check the wire order of the grey harness is as following (from gauge end):
red, green, orange, white, yellow, blue, black and brown.

[Fit Buddy]

Hi Richard,
I can confirm that the f-idc (injector-) is wired to the fuel injection(-).

I can also confirm that the wire order of the grey harness is as following (from gauge end):
red, green, orange, white, yellow, blue, black and brown.

[Richard L]

Good.

There are 30 test pins on board. Please read the following voltage on the following pins for me:

Pin 8 (-) ........ raw negative-going pulsed signal from injector
Pin16 .............. processed IDC%

If you blip the throttle the enigne, you should see some voltage change on those pins.

[Fit Buddy]

Pin 8 (-) ........ 13.10 - 14.10 volts (as the RMP increased and decreased)

Pin16 ............ 0.06 - 0.24 volts (as the RMP increased and decreased)

Not sure if this helps Richard, but I thought I'd try swapping the red and green wires around just in case. The result was exactly the same readings as above.

I also made a video. The lighting isn't the best but I hope it helps.

http://www.youtube.com/watch?v=9UeddFJE3tM

[Fit Buddy]

G'day Richard,

Today I disconnected the red wire of the grey connector from the positive injector feed. I then connected it the positive supply from the ignition. When the ignition was turned to the pre crank position and the gauge turned on, the unit powered up and activated. All three LEDs in the control unit illuminated, I assume indicating that the trigger point had been reached.

In the post crank position, the system operated as it did in the above post, from yesterdays testing.

Below is another video I took showing what happened during today's testing

http://www.youtube.com/watch?v=054nuarOaCs

Cheers,
Orlando

[Fit Buddy]

Hi Richard,

I did as you instructed and put the park jumper link on FDC. When I took the car for a drive the only light which came on on the bar graph was the red "s". This didn't start to occur until about 5000 RPM. My injectors are rated at 750cc each and with this current set up are reaching a maximum of 70% duty, as indicated by the ECU data logger. Hope this helps.

Cheers, Orlando

[Richard L]

I watched both videos. The action of the HFS-3 is working as designed. There are no surprise there.

In the absensce 12Vfeed to the fuel injector(+), the HFS-3 will be seeing the injector(-) as in full-on condition. The IDC% detection circuitry is looking for a digital wave, ie +12v or 0V.

I can see a solution: Why don't you separate the +12V supply to the fuel pump and the fuel injector(+). Relocate the fuel injetcor(+) to the other side of the relay. You still retain the safety aspect of cutting off the fuel at the fuel pump.

It is unlikely the fuel injectors are held 100% full on in the event of an accident.

Question: have you tried driving the car on load and see if the HFS-3 triggers? Or link FDC to see what the H3 picked up.

[Fit Buddy]

Hi Richard,

I have driven the car under full load (22 psi boost and 70% injector duty cycle) and the H3 did not trigger.

I did as you instructed and put the park jumper link on FDC. When I took the car for a drive the only light which came on on the bar graph was the red "s". This didn't start to occur until about 5000 RPM. This means that although my injectors are at 70% IDC, the H3 is seeing maybe 5% IDC, which is well below the trigger point. I this your understanding of the problem?

Cheers, Orlando

[Richard L]

I think there is something wrong for sure. Please pm me your postal address and I will send you replacement controller ahead of you returning the faulty unit back to me.

Just to know that the injectors are not low impedance/peak and hold type. If they are, you need to use the green harness. Please check if you haver a green harness becuase you can use this for conventional injector as well.

[Fit Buddy]

Hi Richard,

I checked my injectors and they are 2.4 ohms, 2 amps peak and 0.5 amps hold. I was not supplied with a green harness on my kit.

I've also sent you all the postal details. Thanks again.

Cheers,
Orlando

[Richard L]

Thanks for the update.

I now know why the system is not picking up the IDC signal. The green harness must be used. On its way.

[Fit Buddy]

Hi Richard,

It has been a few years since I last spoke to you so I thought I?d touch bases and update you onthe progress with my HFS-3.
A few weeks after we last spoke, I managed the get the HFS-3 system running correctly on my car once I fitted the green harness you sent. I got my car tuned shorty after and it made 260rwkw @ 22psi without WI and 290 rwkw @ 26 psi with WI. The car ran like a dream and was a lot of fun to drive. I am not 100% sure why you guys fit the gauge with an on/off button, as I?m sure that no one actually turns their system off once they have driven with it on. I sure as hell haven?t!
Anyway, about two weeks after tuning the car the gearbox decided that it had had enough of the extra power and torque and retired as I was accelerating through third gear. The car was garaged for a year and a half while I sourced and fitted more suitable drive train components to handle the extra power, fabricated my own twin scroll manifold and exhausts system, oh, and started a family. It was a very busy 18 months!
So I finished all the modifications and finally got a chance to get the car retuned a few months ago. The power was roughly the same and the WI is still working like a charm. I can?t speak highly enough of the Aquamist WI system. The system, installed and tuned, including the purchase price of the unit, was less the $1500. Dollar per kilowatt, the Aquamist WI system has been the best value power upgrade to my car in the 10+ years I have been modifying it.
In conclusion, I just want to say thanks to you and your team for a great product and excellent after sales support. It has made a world of difference to do-it-yourselfers like me.

Thank you and kind regards,
Orlando