Fuel Injectors Rating

[Acesneights1]

WOW...opcorn:

 

[gmctd]

Analog = infinitely variable signal, voltage can be negative or positive, frequency from DC to LIGHT

Digital = signal is either on or off - signal can be negative going, as from +5v to 0v, or can be positive going, as from 0v to +5v - usually ground-based, 0v, upper level is supply-rail dependent, frequency from DC to Light

Alternating Current - analog signal crossing a baseline, 0v in AC power circuits, with positive-going and negative-going component - in analog signal circuits, baseline can be shifted to some DC level by the circuitry that generates the signal (output), or reads the signal (input) - usually applied to 60hz ac power generation, positive-going component is equal to negative-going component across the 0v baseline - due to the physical properties of magnets and iron cores, and the electrical properties of copper conductors and coils, ac power voltage generation results in a sine wave, a complex waveform of sine and cosine calculations which cannot be accurately measured with analog meters or digital meters, so the displayed voltage is not even the Root Mean Squared voltage, which would allow calculation of the Peak (and Peak-to-Peak) voltage - high-end DVM's usually have a switchable RMS converter for accurate ac power-line voltage display - it would be switched off when measuring other analog waveforms

Thus, we have:

DC - steady voltage state, either polarity, not rising\falling, no frequency component

Analog - infinitely variable, either polarity, can be "alternating", can have frequency component

Digital - steady state, either on or off (ones and zeros), switchable between ones and zeros, can have frequency component

AC - analog, varying with positive and negative voltage content, sinusoidal waveform in power generation, has frequency component - often applied to varying analog signal waveforms without sinusoidal content

 

[gmctd]

For those interested, here are the answers - most readings depend on the quality of the DVM, sample time and the ability to read multiple waveforms:

This represents a Pulse Rate\Repetition Modulated digital signal, beginning at 0v, rising to 5v, falling to 0v - no analog about it, but definite frequency content:
5v_____
0v_____ ________(a)|____________(b)|_________

What is the effective voltage from (a) to (b)? This is frequency dependent - at 1hz the on-time is minute compared to the off-time - so put a DVM on this signal to read 0v, like a dead circuit, even tho there is a viable signal - at 1million pulses\sec, DVM could read some voltage above 0v, but not 5v, depending on the DVM - "Whups, this module is dead, Vern - toss me a nuther'n off'n the floor, over there!"


5v_____
0v_____ ________(a)|||||||_______(b)|||||||____

What is the effective voltage from (a) to (b)? Same here, but since the on-time has increased, DVM could read some value greater than 0 but less than 2.5v - "Whups, low voltage, Vern - time to change the battery(s) on this rig"


5v_____
0v_____ ________(a)|||||||||||||||(b)||||||||||||

What is the effective voltage from (a) to (b)? Same here, but since the off-time (spaces between the pulses) is still greater than the on-time (pulses), DVM could read some value around 2.5v - "Hit me with a nuther one uv them modules, Vern!"


This represents a 0 to 5v Pulse Width Modulated digital signal - no analog about it

5v_____ ''''''''''''''''''''''''''__ ''''''''''''''''''''''''''''''''' __ '''''''''''''''''''''
0v_____ _______(a)| |___________(b)| |________

*What is the effective voltage from (a) to (b)? The on-time has increased, compared to the pulses above^, so the DVM will flicker to some value above 0v but less than 1v


5v_____ ''''''''''''''''''''''''''____________ '''''''' __________
0v_____ _______(a)|..................|(b)|

**What is the efffective voltage from (a) to (b) ? Here the on-time is greater than 90% so at 1hz DVM will read 5v but with a repeating flicker to some value between 0v and 5v, again depending on sample time of DVM - increasing the frequency will stop the flicker

This represents a 0 to 5v digital Square Wave signal, no analog about it:

5v_____''''''____'''''''''''''____'''''''''''''____
0v_______|.....|____|.....|____|.....|_____

What is the effective voltage of this signal? Again with the frequency, at 1hz DVM could read 5v-0v-5v-0v, depending on the sample time of the DVM - at 1mhz DVM would read somewhere between 4 to 5v - if your DVM would read voltage at frequencies that hi


5v_____ ''''_'''''''_''''''_''''''_''''''_'''''''_''''''_'''''''_''''''_
0v_____ _| |_| |_| |_| |_| |_| |_| |_| |_| |

What is the effective voltage of this signal? Here, at 1hz, DVM could flicker about 2-4v - at 1mhz DVM would read somewhere between 4 to 5v

Remember, in digital signals, the signal is driven to the upper rail, in this case 5v, but is also driven to the lower rail, 0v, so DVM must integrate and average the upper voltage with 0v - you will get different readings in DCV and ACV ranges

An oscilloscope is the desirable tool for investigating computer-controlled systems, as most everything is digital: solenoids, valves, switches, position sensors, etc - temperature and pressure sensors are mostly analog, with variable resistances and variable voltages representing response to change - these can be read with a 'scope or DVM

With inductors the system, inductive kick may be a viable part of the signal, but not even seen by a DVM - inductive kick can be as high as 2400v in a 12v system - the FS coil gives between 100-180v of inductive kick when power is applied, which is why the PNP driver transistors are hi-voltage rated, in addition to hi-current rated, designed to pass a lot of current thru the FS coil

The waveform at question * resembles the Fuel Injection Pulse Width at idle, and at question ** resembles the waveform at FWOT, but on a much higher voltage, as the drive voltage is just under +12v battery voltage, due to solid state forward voltage drop of the bipolar drivers and the steering diode in the emitter circuits - on-time to off-time is determined by demand fuelrate - the max pulse width is never as wide as the duration for the rollers to ride comletely up the ramps

(The apparent waveform misteaks are not correctable)

 

[buddy]

Yes, I was using wrong terms, thinking sampled analog/discrete vs digital bit streams, but discrete is digital. Like sampling an analog 5V DC voltage and switching it on and off, like the sensors do and PCM interprets it.

I'll hook up the scope this weekend to see what it shows going in and out of PMD.

 

[gmctd]

In elctronics, Discrete is transistors'n'diodes'n'capacitors'n'resistors'n'transformers'n'fuses'n'stuff - can have discrete digital and discrete analog circuitry

Integrated Circuit is some of that discrete stuff scrunched together on a teeny silicon circuit board, usually in an *injection-molded epoxy package - can have IC digital and IC analog circuitry

Transistor-Transistor-Logic is mostly direct-coupled bipolar transistors with a few-odd diodes thrown in as token representation

Bipolar transistors are NPN or PNP doped junctions, usually silicon but sometimes germanium flavored, are lo-impedance current devices, transfer function results in odd harmonics, single polarity drivers either pull up to the rail, or pull down to 0

Field Effect Transistors are N or P doped, are hi-impedance voltage devices, operate similar to electron tubes, transfer function results in even harmonics

Complementary Metal Oxide Silicon devices are hi-impedance FET circuits, direct-coupled circuitry is similar to Complementary Output Pair hi-fi power amps, where N device pulls signal up, P device pulls signal down (and vice versa), very sensitive to static discharge

Digital is on or off

Digital circuit control is on or off

Digital logic is multiple on\off circuits parallel-arranged in bits'n'bytes

* Tho't I'd throw that in to maintain the injection-oriented theme of this thread..............

 

[bison]

In elctronics, Discrete is transistors'n'diodes'n'capacitors'n'resistors'n'transformers'n'fuses'n'stuff - can have discrete digital and discrete analog circuitry

Integrated Circuit is some of that discrete stuff scrunched together on a teeny silicon circuit board, usually in an *injection-molded epoxy package - can have IC digital and IC analog circuitry

Transistor-Transistor-Logic is mostly direct-coupled bipolar transistors with a few-odd diodes thrown in as token representation

Bipolar transistors are NPN or PNP doped junctions, usually silicon but sometimes germanium flavored, are lo-impedance current devices, transfer function results in odd harmonics, single polarity drivers either pull up to the rail, or pull down to 0

Field Effect Transistors are N or P doped, are hi-impedance voltage devices, operate similar to electron tubes, transfer function results in even harmonics

Complementary Metal Oxide Silicon transistors are hi-impedance FET devices, direct-coupled circuitry is similar to Complementary Output Pair hi-fi power amps, where N device pulls signal up, P device pulls signal down (and vice versa), very sensitive to static discharge

Digital is on or off

Digital circuit control is on or off

Digital logic is multiple on\off circuits parallel-arranged in bits'n'bytes

* Tho't I'd throw that in to maintain the injection-oriented theme of this thread..............

You lost me long ago

 

[buddy]

So if I have reference 5VDC, and a magnetic pickup switch that activates when a metal tooth spins by, you will get an analog discrete signal that looks just like a digital discrete signal, and the PCM can take that analog signal and interpret it into digital bits.

You can modulate that 5VDC with digitally controlled switching, does that make the signal digital, or just a digitally synthesized analog signal, which was where I was heading comparing it to digital bit streams.

 

[gmctd]

Not perzackly - a coil around a magnet will give an analog signal something like a sine-wave when the tooth sweeps by, as in the speed sensor for the speedometer, and the two speed sensors in the 4L80E - those are 2-wire twisted-pair because of the low-voltage ac signal, and go thru an amplifer\squaring circuit in the PCM and VSS module for conversion from analog ac to digital suitable for PCM logic circuitry

In a Hall-effect device (magnetic-type) sensor you will get a digital off till the tooth sweeps by the pickup, then an abrupt rise to on then back off - it is a square pulse, as from the Crankshaft Position Sensor (and Cam Sensor in gassers (patooie!)) - this type sensor has 3-wires, one for +5v power, one for ground, and one for digital signal to PCM logic circuitry (PCM is +12v powered, but has internal +5v regulators for logic and sensor reference)

You will get a similar square on-off pulse when the window sweeps between the Infra-Red diode transmitter and the photo-transistor receiver, as in the Optic Sensor - this type sensor will usually have 3-4-wires, +5v power for the diode, ground for the diode and transistor, digital signal output

The analog tachometer in your truck operates off one phase of the 3-phase winding in the alternator, which is a variable-frequency 3ph ac generator with solid-state rectifier diodes and regulator

A digitally-synthesized signal is how a digital computer with ones'n'zeros makes an analog signal - similar to the on-screen display of curves on the old b-w, cga, vga monitors, which was a series of digital steps that formed coarse curves and circles - the more and finer the steps the smoother the curve

 

[gmctd]

Ok - I think what will make this easier to comprehend, Buddy, is if you lay back.....get comfortable........now take slow deep breaths......relax......slow breaths.....think peaceful thoughts......slow, even breaths........relaxing.......breathing........now, wipe computer synthesis from....relaxing,breathing....your mind........peaceful..........receptive.........

The 6.5 PCM is too primitive for computer synthesis - the nearest thing to c\s in your truck is the stereo\cd\dvd\mp3\serious radio - also the radar detector - then your cell phone - blackberry - pacemaker - XBox - Wii - Buck Rogers space toy.................

Here are the modules, sensors and signal-types used by the PCM - passive sensors are part of a 'nuther separate circuit, do not generate output without external influence - active sensors are solid-state devices requiring power and ground to generate a signal on a third wire:

IAT, ECT sensors to PCM are passive temperature-variable resistors in a +5v ref voltage-divider circuit in the PCM - an analog-to-digital converter in PCM changes the variable analog voltage to 16-bit digital 1-2-4-8 1-2-4-8 1-2-4-8 1-2-4-8

Boost and EGR sensors are active analog-voltage pressure transducers using +5v ref - the analog voltage to PCM varies as pressure changes - an analog-to-digital converter in PCM changes the variable voltage to 16-bit digital

Crank Position Sensor, Optic Sensor are active - pulses increase as rpm increases - to PCM:
5v_ ''''''''''''''''''''__ ''''''''''''''''''''''''''' __ '''''''''''''''''''''
0v_________| |___________| |________

NOTE: PCM can use clock ticks to turn on electronic switches for any length of time, as below:
5v_ ''''''''''''''''''' __ '''''''''''''''''''''''''''' ______ '''''''''''''''''''''
0v_________|||___________||||||||________

Wastegate Solenoid drive, pulse width modulated - WG duty cycle runs ~66%, decreasing to reduce Boost, increasing to raise Boost - also EGR solenoids - from PCM:
~10%duty cycle
12v_____''''''_ ''''''''''''''''''''''''''''''_''''''''''''''''''''''
0v________||___________||_________

~50% duty cycle
12v_____''''''_____ ''''''''''''''''''''_____ '''''''''''
0v________|||||||_______|||||||____

~100% duty cycle
12v_____''''''_______________________
0v________|||||||||||||||||||||||||||


Fuel Inject signal from PCM to FSD - pulse width increases to increase fuel rate - (Note:any of these three signal examples may be inverted - I've slept some since '03\'04) :
5v_ ''''''''''''''''''''__ ''''''''''''''''''''''''''' __ '''''''''''''''''''''
0v_________| |___________| |________

Fuel Solenoid Driver to FS - pulse width increases to increase fuel rate - from PCM:
Idle
12v___''''''''''''''''''''''''''__ ''''''''''''''''''''''''''' __ '''''''''''''''''''''
0v______ _______| |___________| |________

FWOT
12v___ '''''''''''''''''''''''''____________ '''''''' __________
0v_____ ________|..................|___|

:
Timing Stepper Motor drive, 2 phase - each pulse steps motor ~5* - TSM reverses direction when lower signal leads upper signal - from PCM:
5v_____''''''____'''''''''''____'''''''''''''____
0v_______|.....|___|.....|____|.....|_____
5v_______''''''''''''____'''''''''''''____'''''''''''''____
0v___________|.....|____|.....|____|.....|_____


VSS after being squared from magnetic pickup - output frequency varies with vehicle speed - mag pickup is passive, becoming 'active' as "tone-wheel" tooth approaches sensor: a real conundrum - to PCM:
5v_____ ''''_'''''''_''''''_''''''_''''''_'''''''_''''''_' ''''''_''''''_
0v_____ _| |_| |_| |_| |_| |_| |_| |_| |_| |


Speedo, Tach drive from VSS, PCM - active - frequency varies with vehicle speed and engine rpm - to speedo, tach:
5v_____ ''''_'''''''_''''''_''''''_''''''_'''''''_''''''_' ''''''_''''''_
0v_____ _| |_| |_| |_| |_| |_| |_| |_| |_| |


4L80E = PCM uses pwm at ~30hz to apply TCC clutch, PCM uses prm to vary line pressure



__________________

 

[Goldsburg]

Because the rollers ride up the ramps quicker as rpm increases, with resultant quicker pressure rise - the rollers do not need to make the entire transition from the valley to the ramp peak to generate pop pressure - residual pressure in the pipes mean the pressure does not have to build from 0 - housing pressure @25psi at idle rises above 125psi as rpm increases, so pressure is greater than 0 when rollers are in the valleys at the start of the ramp

So I guess that the pump is not "fixed start and variable ending" (because of the spill valve), right? And BTW, the the residual line (aka "pipes" using your vernacular) pressure is controlled by the delivery valves at the outlet(s) of the head (ya know, where the "pipes" connect?). Not the housing pressure.

Sooooo really the pump is technically capable of nearly infinite start and nearly infinite end timing, within the given limits of the ramp. This system is very similar in functionality to the injection system of Deere PowerTech engines...

Regards,

 

[gmctd]

Hmmmm....would appear as tho somebody else was texting some floozy when he shoulda been concentrating on the context, eh - put your cellphone on silent running, vibrate off, then reread the part about the one-way valves in each port in the distributor head, and the indicated function..............

Hmmmm, some more..........looks like I didn't call them specifically 'delivery valves', so it behooves me to amend that, soonest, if no one raises any objections

Because housing pressure increases and waste-volume increases and rpm is variable and residual line-pressure in the pipes is relatively constant, IP timing can be advanced within the constant-beginning concept - keep the constant-rpm constant-volume pumping theories in mind, but factor-in the variable-rpm variable-volume (and variable-pressure, if you will) concepts - makes it easier to accept until someone from S comes along and blows it all wide open.....shortly after hell freezes over......................

FYI - in automotive engineering lingo (and parts and service manuals), pipes are non-flexible "lines" made of metallic metallurgy - you know, like in exhaust pipes, instead of exhaust tubing (Hmmm...exhaust lines.....how cute!...'yeah, put me summa thet 4" alumnised exhaust line on there, buddy!') - hoses are made out of rubber metallurgy - hosers are.....neb'mind - small plastic tubing is sometimes referred to as tubing, and is usually of plastic metallurgy - oddly enuff, modern-day fuel and hydraulic pipes are also made out of plastic metallurgy - just something else to argue about with the parts guy..........

Strangely, piping is figgered on the inside diameter (which is why 3/4" pipe won't fit thru a 3/4" hole), where tubing is figgered on the outside diameter (why a 1/2" bit won't fit into 1/2" tubing) - yet we got tubes called pipes - somewhat like motor oil, and motorcycle, and Indianapolis Motor Speedway, not to mention inner tubes, etc...........

 

[turbovanman]

The signal from the PMD to the FS is not digital.

Change in frequency would not show a change in amplitude on a DVM, thats just nonsense. Voltage is determined by the peak to peak amplitude, has nothing to do with frequency. It could be 60Hz like commercial power 120V, or that same 120V could come out at 400Hz or whatever.

The signals on these trucks ARE digital, this link tells it plain as your nose, :thumbsup:

http://cbdd.wsu.edu/kewlcontent/cdoutput/TR502/page8.htm

OK but what that thread was about was Tony kept referring to the injectors as nozzles which was getting me confused. The GM 6.5 Manual also refers to what we tend to call injectors, nozzles . Tony was trying to explain to me that what I have a nozzles not "injectors". That is why I was getting confused. When Someone says nozzle I think like the end of a powerwasher and that would not make sense. The engine being discussed in that thread was a 3208T cat but same thing really applies to 6.5 ?? Or am I just more conused ??
The other issue was I could not get the truck to strat even after priming i but that was because I was not priming it properly. How we finally got that truck started was dragging it down the road in gear to spin the motor faster than the starter could because as I have said before I really really don't like ether even though in the case of a low compression 3208T it's almost a nessecity..

I have never had to prime a 6.5 or 6.2 with an electrical fuel pump, I just turn the key on for a few secs, off, then on a few times, then crank, usually fires up with 10 secs, :thumbsup:

While we are talking about injectors, what makes 40/80 hp injectors so?

 

[gmctd]

The "tuning" of the IP..................

And, tnx for that link, turbovanman - my 'search' acumen is infamously notorious

BTW - would appear as tho we have similar exhaust\tailpipe (there's that p-word, again!) preferences, from the 'blue oval' - mine's late '90's F350 cc longbed powerstroke, 3" down-pipe, 3.5" back (cat's in the back yard, hiding in the tall-grass), cut'n'electrically-resectioned with 308ss rod - smooooth.........

 

[turbovanman]

The "tuning" of the IP..................

And, tnx for that link, turbovanman

So putting on "40/80" hp injectors without IP mods has no gains?

NO worries, my head started to hurt after the first argument that they are analog, :nono: lol.

 

[gmctd]

Correct - if the injectors are capable of +80hp at 60lbs\hr fuel rate, but yer pump puts out only 40lbs\hr, you def ain't gonna get no 80hp increase outta them injectors, right? Gotsta turn up the pump to get the job done - was easy with the DB2

Could get some improvement if original injectors were restricting\limiting full functional flowrate of the IP, and the potential engine output

 

[buddy]

With the link as an argument though that means I could take a 12VDC power signal on a momentary switch and press it in at a frequency of my choosing and call it digital. Which it is not. I still would not call a switched power source a digital signal, digitally switched perhaps.

 

[gmctd]

Not necessarily - to be digital usually implies switching is by an electronic source, tho could be by mechanical source, such as a cam-operated switch as input to a digital counter

- or, the brake switch input to the PCM, or the Cruise switch inputs to PCM - or dipswitch inputs in any circuit - these types of digital signals are usually known as STATUS inputs, ON or OFF to indicate a change in status of some circuit or device within the computer system, that affects the system

- in your example, it would be digital also if you were part of Pavlov's experiments, pushing that button due to external stimuli, trying to maintain a specific count repetition to an elecric counter in order to avoid the hi-voltage electric stimulation of certain sensitive parts of your anatomy - knowwhuttimean, jellybean?

Then, there is the ubiquitous RESET switch - certainly no less digital for being manually activated with but a single digit on either hand (or foot) to satisfy a status input, yet having global consequence: it amply satisfies your example, 'n est ci pa?

Let us not also forget the Power switch on nearly all modern electronic devices - and on your PC - no longer a real power switch that connects\disconnects ac line power, it, too, satisfies a status input that alerts the continuously-powered CPU to begin awakening the various intelligent devices within it's managed system(s), quickly restoring commerce with the gui display and keyboard, and modem under authorized conditions - also allows unscrupulous businesses and giant operating system software conglomerates to remotely awaken your PC in the wee hours of the morn while you yet slumber, perhaps in alcoholic stupor, for an unauthorized, unbridled session of ransacking your files for passwords, i.d. numbers, account numbers, phone numbers, contacts, etc, anything usable\salable on the www - be afraid.....be very afraid................

 

[Brooklyn Tow]

also allows unscrupulous businesses and giant operating system software conglomerates to remotely awaken your PC in the wee hours of the morn while you yet slumber, perhaps in alcoholic stupor, for an unauthorized, unbridled session of ransacking your files for passwords, i.d. numbers, account numbers, phone numbers, contacts, etc, anything usable\salable on the www - be afraid.....be very afraid................

ROFLMFAO........good 1.

 

[gmctd]

Me, too.........but the Master switch on my surge-protection and power center is in the OFF position when I walk away from this PC at nite, completely disconnecting ac power from the PC and all peripherals - even have a switch to disconnect the modem from the phone line - my PC is in enforced seclusion while I sleep, aye, perchance to dream........

 

[Missy Good Wench]

Too much fretting over all this high tech info.

Set the stock Nozzles to the top of the spec, keep the pop pressures even across all 8 nozzles and Live Long and Prosper

Too much goes on inside the Fuel system on the DS4 to really worry about it.

The whole system is great (When its working)

The Marine injectors were designed to accomodate the DB2 high output and the DB4 High output pumps.

The main reason we dont normally use the Marine pumps on the trucks is that the heat rejection through the cooling system falls short of the task at hand.


Use stock components and keep the stuff in spec and it will work great.


Missy