Flow bench?

[caladash]

I feel ya on he fun part! Hell I'm building a somewhat budget friendly p-pumped 7.3 just because people said it can't be done. I'm all about a challenge. The flow bench seems extremely challenging in my opinion. You basically have to simulate alot of engine parameters just to fire an injector. CPS, fuel desired, MAP, and so on. So I'm thinking a spare head to put the injectors in, a pump to pressurize the oil rail, and a pump for fuel. Now the electronics side of the things I see no real easy way to simulate the IDM signal without having to use a signal generator, an oscilloscope to measure an actual IDM signal, then setting that reading into the sig gen and using the o-scope again to measure it. Also how are you going to measure your thousand shots? Frequency counter? Im the last person to $hit on someone else's idea. This is just how I see it being able to be done. I also have over five years of calibration (metrology) and repair experience with alot of emphasis on the RF and microwave side of things. All in the marine corps.

 

[Hotrodtractor]

When you write the computer application to generate the FDCS and CI signals you make some of the user inputs, RPMs, PW, and shot count - then let your computer do the rest - it can generate the signal correctly for the right speed, PW, and for the correct number of times every time.

 

[mandkole]

I just rebuilt a sweet running small block.... can someone assist me with building a dyno to run it? oke:

I agree, I was fascinated by my first DIY injector rebuild and testing on the flowbench. Best of luck to ya man!

 

[Buffalo444]

I just rebuilt a sweet running small block.... can someone assist me with building a dyno to run it? oke:

I agree, I was fascinated by my first DIY injector rebuild and testing on the flowbench. Best of luck to ya man!

Haha, very funny.

I figure worst case scenario, as long as I don't pay out the ass for hard parts, I shouldn't be invested too deeply into it. And I should learn quite a bit along the way, which should be worth it in the end.

 

[rsater1]

SKY CRAFT IN OLRLANDO FLORIDA HAS WALLS OF ALL KINDS OF MILLITARY OSSILASCOPES..how ever u spell it .

 

[N2GN2]

I'm building a flow bench. Still working on the electronics. You can simulate the FDCS and CI signals to the IDM with a $20 Arduino board.

 

[ja_cain]

I'm building a flow bench. Still working on the electronics. You can simulate the FDCS and CI signals to the IDM with a $20 Arduino board.

Those Arduino boards are quite handy for how cheap they are. I have a Labjack (or two) that would probably be overkill. Can't wait to see what you come up with.

 

[N2GN2]

Those labJacks look pretty cool! It's all about writing the software. We only need two 12vdc square waves. Pretty simple. Anyone's contribution is more then welcome on this project.

 

[ja_cain]

Those labJacks look pretty cool! It's all about writing the software. We only need two 12vdc square waves. Pretty simple. Anyone's contribution is more then welcome on this project.

If you can program in C you can do a lot of stuff. Been meaning to sit down and just learn it, but my other hobbies and life keep getting in the way. Lol!

 

[N2GN2]

I know just enough to get myself in trouble. My brother-in-law is the one who can code. Here's where I'm at if anyone was interested.

//Powerstroke Diesel Flow Bench Controller

#include <digitalWriteFast.h>
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

const int FDCSpin = 13;             // Fuel Delivery Control Signal
const int CIPin = 10;               // Cylinder Identification
const int buttonPin = 2;            // Start Button
const int speakerPin = 8;           //Speaker
bool buttonState = LOW;              // Button is off
double RPM = 1000;
double PW = 1.5;
double FDCSoffus = int(1000/(RPM/60)/4 - PW);
int PWus = int(PW*1000); 
int ciCnt;
int totalCnt;
bool CIState = HIGH;
     
void setup()
{
  lcd.begin(16, 2);
  lcd.print("READY TO TEST");                 // Waiting for button press
  pinMode(FDCSpin, OUTPUT);                      // Fuel Delivery Control Signal
  pinMode(CIPin, OUTPUT);                      // Cylinder Identification
  pinMode(buttonPin, INPUT);                  // Start Button
  digitalWriteFast2(FDCSpin, LOW);
  digitalWriteFast2(CIPin, LOW);
}

void loop()
{
  buttonState = digitalReadFast2(buttonPin);  // Read Start Button State
  
  if (buttonState == HIGH) runInjectorTest(); // Button is pressed
}

void runInjectorTest()
{
    lcd.print("TEST RUN");
    tone(speakerPin, 500, 500);
    delay(700);
    tone(speakerPin, 500, 500);
    delay(700);
    tone(speakerPin, 500, 500);
    delay(700);
    tone(speakerPin, 2000, 500);
      
    while (totalCnt < 2000)
    {
          digitalWriteFast2(CIPin, CIState);
          while (ciCnt < 4)
          {
              digitalWriteFast2(FDCSpin, HIGH);
              delayMicroseconds(PWus);
              digitalWriteFast2(FDCSpin, LOW);
              delayMicroseconds(FDCSoffus);
              
              ciCnt++;
          }
          CIState = !CIState;
          ciCnt = 0;
          totalCnt++;
    }
    
    lcd.print("TEST FINISHED");             // LCD after loop is complete
    tone(speakerPin, 2000, 500);
    delay(700);
    tone(speakerPin, 2000, 500);
    delay(700);
    tone(speakerPin, 2000, 500);
    delay(700);
    tone(speakerPin, 500, 500);
    totalCnt = 0;
 }

 

[superpsd]

Wonder if one could hook up a pcm and idm and feed it the signals needed. Then use tuning software to adjust PW and build a test tune. If you used an hpop the pcm would control IPR and the requlator is covered. You wouldn't need a huge aftermarket pump just run twin hpops with dual motors. Setup two heads and test all 8 injectors at the same time. Bringing things close to a real world environment. Icp is covered its in the head. Ile in the Hpop. Tps is simple. Just need the cam signal.

Sounds like a lot of work for the average guy I rather buy a good running 7.3 with good compression numbers wire it up and slide some injectors in and see if they can be dialed in to idle and run good. It would not be as good as a test bench but it the motor sounds good humming at 3500 rpm and all the PIDs look great call the injectors ready for the real motor.

 

[N2GN2]

Sure, it can be made as complexed or as easy as one sees fit.

 

[Charles]

It looks like you're calling a subroutine that's off-screen of that shot to actually do the dirty work of running FDCS and CID in that main routine.

Do you actually know the relationship between CID and FDCS in order to correctly drive the IDM? Or is that a sub-routine that others have actually written for that board you are using?

Bascially, that is the only part that will, or will not allow this to run. The IDM has to accept your communication link. Depending on the chipset used, this can sometimes become an issue, but surely by now even a 5 dollar chip is fast enough.

Explain the communications protocol between PCM and IDM in terms of what actually happens to FDCS and CID as the engine advances through say, just before cylinder 1 until just after cylinder 4. Then everyone will know if you need help, or if you've got it handled.

It's very straight-forward, it just requires some decent precision compared to what we're normally used to if you're real job isn't electronics software engineer, lol. The IDM has a short window, outside of which it will reject your signal. The second time it will reject your signal happens at elevated rpm, where your FDCS will get "stacked" for lack of a better word. This will be of no matter for a flowbench program though, you should not be at that range, except for testing refill possibly.


On Edit:

And I would forget doing this without a scope to debug with. Do not expect to use an IDM as a debugging tool. Too many reasons why it would never fire. You need to see your signals, because don't forget..... it takes your chipset TIME to turn around and execute a command. Time that you have to account for.

 

[ja_cain]

I wanted to include this for all of the individuals that are not familiar with the acronyms and signals used in communication between the pcm and idm. Hopefully this helps.

Sent from my SCH-I545 using Tapatalk

 

[Charles]

That diagram is the basic idea, but it will not run an IDM, except by blind chance, with that chance being like 1 in 10,000 that you happened to line everything up right.

In fact, looking closer, if you produced signals exactly like those, it would never run. 0% chance.


On Edit:

I thought I remembered one time arguing with people that the communications protocol between PCM and IDM would not support but XXX pw at XXXX rpm and had quickly generated the needed signals to show the limits of the com. protocol. Turns out it was still up on youtube, so, it just so happens that this is also the exact signal generation anyone needing to run a flow bench using a ford IDM (the preferred method) would need.

Look closely, because this is an accurate and real com link that would, and has run a 7.3 engine, as well as flowbench. I won't just spell out every last nook and cranny because that information was painstakingly earned and handed to me many years ago. Although I think it has all been stated in plain English since then, you are in fact wanting to build a flowbench, possibly to directly compete with those people. So, you need to do some legwork, but this is a proper, running com link I generated long ago.

https://www.youtube.com/watch?v=RfHF0hZdUZw

 

[ja_cain]

That diagram is the basic idea, but it will not run an IDM, except by blind chance, with that chance being like 1 in 10,000 that you happened to line everything up right.

In fact, looking closer, if you produced signals exactly like those, it would never run. 0% chance.

I think there is a better diagram out there, but the image quality is poor.

Like you said, scoping everything is the way to go about it. I have a digital scope and may just grab some actual waveforms and post them up.

Sent from my SCH-I545 using Tapatalk

 

[Charles]

I think there is a better diagram out there, but the image quality is poor.

Like you said, scoping everything is the way to go about it. I have a digital scope and may just grab some actual waveforms and post them up.

Sent from my SCH-I545 using Tapatalk

I made an edit to my last that you should not miss.

Btw, excuse the slow speech, I think I had been so worn down by idiots at that point that it was affecting my ability to care enough to speak clearly, lol. The same morons that continue being morons today were up in arms adamantly explaining how they could tune a truck to run hellacious pulsewidth at clearly impossible rpm points. Ever notice how the same idiots come up with the really dumb sh*t?

Anyway, turns out that video provides this thread with a good view at a real IDM com link.

 

[Hotrodtractor]

Good stuff. Glad to see someone tackling the signal issue with a nice handy Arduino.

 

[N2GN2]

I wrote an Arduino sketch and my brother-in-law who is a software engineer helped me clean it up. We wrote the code as more of an example because we didn't have actual truck scope files yet. I think I'll write a new simple sketch as that one is hard for others to read with all the variables. I think the first FDCS square wave lines up with the first CI square wave change and the 5th FDCS lines up with the second CI square wave change. Now spread out FDCS between the CI and the PW determines how long each FDCS is. I have a cheap PC o-scope that I'm learning to use.

 

[Charles]

I wrote an Arduino sketch and my brother-in-law who is a software engineer helped me clean it up. We wrote the code as more of an example because we didn't have actual truck scope files yet. I think I'll write a new simple sketch as that one is hard for others to read with all the variables. I think the first FDCS square wave lines up with the first CI square wave change and the 5th FDCS lines up with the second CI square wave change. Now spread out FDCS between the CI and the PW determines how long each FDCS is. I have a cheap PC o-scope that I'm learning to use.

Do more research, scope a running truck or look closer at the video I posted. I don't think you'll ever drive an IDM unless you scope a running truck or someone tells you exactly what to do. Even if someone tells you exactly what to do, you'll still never trigger the IDM unless you have a scope to view your output on. Remember, it takes TIME for your chip to execute commands.

Scope is the first order of business for you.