I am thinking if I can put a delay loop at idle only in the injection signal, wouldn't this reduce or elimate pre-ignition?

Do you have a pre-ignition problem? Would you delay the FSD signal to the Fuel solenoid? Curious, so tell us whats going on.

I assume all the noise at idle is pre-ignition on a diesel. If not, what is making all the noise?


Thanks,

I am looking at delaying the fuel injection signal into the PMD (Pin E).

Could you explain how the loop works. Would you dial in the exact delay for desired idle? I would assume the delay would be in fractions of a second.

Are you trying to add wire before it reaches the PMD to get the delay you need? You will only be talking about nanoseconds, unless you have a really LONG wire.


You are trying to delay the fuel opening time to quiet the engine down? Wonder if you could do something with the advance instead?

Combustion in a Diesel engine can occur when increasing cylinder pressure results in a temperature of ~1700deg.


Injection timing is set to place fuel into the cylinder after temps have reached that level.


Fuel injected early results in some fuel never reaching combustion temp, and the un-ignited fuel passes out the exhaust as white vapor.


Fuel injected late results in some fuel not burning when combustion temp starts dropping, and the un-burned fuel passes out the exhaust as black smoke.


Pre-ignition does not occur in a Diesel engine.


Diesel rattle occurs as the combustion flame front causes stress shifts in the heads, cylinder walls and pistons.


The 6.5L engine is of the indirect injection type, where fuel is injected into a separate pre-combustion chamber in the head.


The different sound in the 6.5L occurs as combustion takes place in that 'pre-cup', with the resultant stress shifts transferred into the heads.


Burning high-quality fuel with lubricity additive and cetane booster will ensure that you continue to hear that sound for many years to comehttp://www.dieselplace.com/forum/smileys/Cool.gifEdited by: gmctd

If you want to take some of the "rattle" out of the engine then advance the timing to -.25TDC. You might have to move the Injection Pump oh so slightly before you get into the programming. Turn the pump toward the passenger side. Now you will need a bi-lateral reader like a Tech II to complete the job. Just turning the pump won't accomplish anything.

GMTCD,


Are you saying there is no way to lessen the noise ( except those items you mentioned)?

As Charlie suggested, you can alter injection timing a little, but that could also reduce power output.


What Cummins and NavStar have done is refine Electronic Fuel Injection (EFI) technology to allow pilot injection, and increase injection pressures.


Pilot injection allows a minimal initial combustion event, reducing the shock to the combustion chamber, along with the associated noise.


As combustion progresses, more fuel is injected to develop power.


The high injection pressure, up to ~22000psi, super atomizes the fuel, allowing complete combustion of each injected fuel charge.


Recently rode in a '04 Cummins-dodge 350hp 6-spd manual, showing around 23-24mpg.


Bro kicked it 50-75mph in 6th as traffic opened up.


Turbo began to sing like an 18-wheeler, and it pulled like a bad-boy 454.


Can still tell it's a Diesel - wouldn't be as much fun driving it if it were any quieter, tho.


Gots to love the sound of BTU's being noisily forced from their enviroment.


Edited by: gmctd

rut-rut-rut-rut-rut-rut-ruuuuOOOOOOOOOOOOOOOm...rut-rut-rut-rut


gotta love it

Could it be possible to loop the signal to where you get a preinjection and then an injection on the DS-4 pump? prom could always be tweaked to compenste for timing change.

How much detonation clatter are we talking about here HRJ? If its only at idle, either watch with a scanner to see where des/act timing is, or use a flash light to see if the stepper motor is bottomming out. if either condition is present, retard the pump so it can reach desired timing and the problem will be solved.

I found the stepper arm, finally, I have to look under the watercrossover on mine with a flashlight. I'm still not sure how it corresponds to timing on the scanner. I can't tell if it moves up and down or not but it's not that easy to see.Edited by: quantum mechanic

down = internal timing retard, up = internal advance timing. the higher the desired/actual timing, the more the stepper pulls the contol lever up to advance timing, its that simple.

Hey GMCTD, I was thinking tonight about what you had said before about the way the newer Cummins and IH's work with pilot injection. . . Is that two seperate injection pulses per stroke, or like a modulated slow opening type of event.

Wasn't the Duramax the first one (at least in the US) to use pilot injection?

The injectors are electric solenoid valves, allowing full control of timing and rate - I would assume it is modulated rate, starting slow and increasing into the power stroke.


Haven't taken the time to get into it yet, but axe me again in December.

I was wondering how more it works. I don't have a clue who was first or not.

It makes a huge difference. If you see a dodge that says Cummins on that is running and can't hear (and feelhttp://www.dieselplace.com/forum/smileys/HiHi.gif) it, then it has the pilot injection.


A properly running stock electronic 6.5 is quieter than most of them. If you dump a quart or two of ATF or 2 cycle oil in the fuel tank, it should make it even quieter.

I've heard that ATF is not a great thing to add to the tank. It is not combustion friendly from the little I've read. Does great for everything until it goes boom in the cylinder.


Does the 2 cycle oil cause any smoke or anything, or is that just on weedeaters?

My Dr sez add 2oz 2-cycle oil, which is formulated to burn at combustion, per 20gal for lubricity - your inj pump will love you for it.


2-cycle engines generally get 2-to-4oz per gallon.


ATF is red, can cause some problems if vehicle is stopped for DOT fuel opacity test - red Diesel is tax free, for Farm Use only.


The clincher is : Diesel fuel is a light oil - IT'S SUPPOSED TO SMOKE, fer cryin' out loud! ! ! ! ! ! ! ! http://www.dieselplace.com/forum/smileys/Wink.gifEdited by: gmctd

Pilot injection is delivered from a 25,000 psi common fuel rail. The "pilot" part is a small pre-injection that comes a nanosecond before the actual injection. The theory is that the main injection will burn better if a small amount of fuel is alreadly burning.


Biodiesel is my prefered lubricity addative. After examining my last injector pump, biodiesel was found not to have caused it's failure, as it was the optical and fuel solenoid. Biodiesel will change the sound and smell of your diesel engine at greater than 2%. Sounds like a well oiled machine and smells like what ever oil your burning.(resturant oil=french fries, or type of food, virgin oils smell less)

Powerstrokes 96+ use a 'split shot' injections, so no the Duramax was not first. Common rail systems acually use a series of small injections, as many as 7 in one firing stroke.


As far as your analysis of effects of biodiesel QM, I'm not saying it DID cause your failure, but it COULD have concievably contributed to it. Biodiesel is a much higher viscosity, so things tend to move slower in thicker fluid (such as fuel solenoids) And its also known to degrade someplastics, possibly the optic sensor and the insulation in the FSOL. Don't have any personal experience with it, but I'll hound my Stanadyne rep about it again next chance I get.Edited by: Texas Diesel Guy

I noticed all my o-rings had lost their pigment coating(red/blue) but were intact. My optical died because I opened the pump too many times when I had that trouble and the wires came loose on the encoder. Then the fuel solenoid broke because the armature was contacting off center and torqued the head of it's screw off. The bad load of fuel I bought was eating fuel lines and water in fuel sensors, probably full of benzene and other solvents by the way it made my head hurt.


Ethyl-esterfied fuel oil or biodiesel for lack of a better word was not the problem.

good enough for mehttp://www.dieselplace.com/forum/smileys/Embarrased.gif