i just figured my fuel ecomomy getting 13 mpg high way at 120km. per hour

 

where are you crossbones ive been playing all day i pulled all my injectors and bench tested 2 had leek down and i replaced them with nown good ones cross threded #8 injector lind oops the only one i had was for a 6.9L it a little shorter but it dosent seem to run any differnt did what you said filled her up 4x the dose of howes and went out now on flat cruise 11.mv up hill was better 14,15mv. and advaced was higher numbers flat cruise 13mv. up hill 18,19mv.what time zone are you in cause you dont seem to be around

 

On a side note.... if you did this check on individual GPs you may be able to isolate a bad injector, low compression or any other interesting phenomina.

 

So now that were going somewhere with this, well done! With truck warmed up advance off I checked my #1 GP and got 13mv. This is quite different than Vintage super duty, but should be same type of GP's in my 93! Confirm this check being done off of one GP at this time, or are you hooking up the VOM to the Controller terminal to get a reading off the entire system?

Truck starts well and idles evenly so I do not think there are any bad GP's, do have ram air intake and headers with big exhaust for N/A engine. Also at idle the pyro reads about 250.
When I verify the meter hook up procedure I can get some #'s and relate the EGT at the same time.

 

i hooked mine right to the gp realy and i know all my gp's are good i just checked them the other day 0 ohm's to ground on all of them im going on a 230 mile trip tomorow and im taking readings all the way

 

Hello everyone.........I am dealing with a extend family member medical issue.......please be understanding of my time................

I really would like people to just get information about their reading now and not make any major changes............I do not want people working their royal off on this........there is a lot to understand about what the readings are telling you.........the things to learn are very simple and very logical, BUT......some of them will be the Opposite of what you have been lead to believe about tuning a diesel engine......................

I believe we have got to the point where people are at least willing to consider that this method just may have value.........so.............the very first thing is this.........Forget every thing you have ever been told on how to test a glow plug to see if it good or bad..........not only will this test be good for tuning the engine...................it will help cold starts by 100% even with a set of brand new Beru plugs and it will Completely Stop glow plug "blow out"...................

The Only Way to test a glow plug is in the (hot) engine with the engine running................(all new glow plugs Must be Tested as well............we Assume Nothing..............)

With the glow plug relay disabled, we disconnect the wiring harness at every glow plug.............

Start the hot engine, set the idle at about 2000 rpm's.............check the readings at every cylinder and write the reading down......keep track of the cylinder/reading...............what we want is all glow plugs to read within about .5 mv's of each other.........example: say we have six plug readings within this range and one much higher and one much lower...............exchange these two glow with two plugs that were within range (noting the cylinders) and retest..........this tells you if it's the glow plug or the cylinder.................if it is the glow plug and even if they are brand new...............replace them...............it is not uncommon for 20% of new glow plugs to fail this test of any brand..............any engine...........

Now, if the above test showed that there is a issue in the cylinder.........Do Not just jerk out that injector without having a full set of replacement "o" rings.....................and if you are super tuning your engine,,,,,,you need to know what is the torque speck on the injector assembly.....(sorry I do not have this info at this time.........trust Nobody except from the factory manual)...................maybe someone can post these specks...............

now if you just want to clean your injectors.........disassemble them and keep Every Single Part Isolated to That Injector..........you can use carb cleaner, oven cleaner,,,,any strong cleaner...........use wood to rub the small parts........you can not over clean them.........

Now, assembly of the cleaned injector is CRITICAL.........if I am not explaining this well, then Ask questions until I have explained it to your satisfaction.................

After cleaning, spray the nozzle and pintle with WD 40........from this point on Do Not Touch the pintle with your bare finger ...................now with the nozzle and pintle wet with WD 40, put the pintle in the nozzle and without much pressure slowly turn the pintle while you work it up and down in the nozzle.........you will "feel it free up"...............

the next step is CRITICAL...........now with the pintle and nozzle assembled........turn the nozzle and pintle to about a 60° angle to the ground...........while at this angle pull the pintle out to its full range of movement (on a used pintle you should see the "Range wear marks").....when you "let go" of the pintle....it MUST GO TO THE SEAT WITH GRAVITY ALONE............test it several times slowly turning the pintle to different clock positions............IF you can not get the nozzle/pintle this clean.........REPLACE IT........

Now, if you have the means to pressure test the nozzle pop off...........Example: say your pop off speck is 1425 PSI and it a "perfect world" all injectors are at this pop off.................there is another test that is Super Critical.................this is the drip test............this test separates the men from the boys ................this is another time that I am telling you to forget what ever you have been told.................on this example of a pop off of 1425 PSI.................MY SPECKS is that this injector MUST HOLD A PRESSURE OF 1420 PSI FOR DAYS AND NOT LEAK A DROP,,,,,,,,,,,,if it leaks down, it is NOT cleaned well enough or it needs to be Replaced on the spot.......................do not worry about fan spray patterns at all.........these too specks will Give you the Correct Pattern for Your injectors.......

I am not asking every one to run out and do all this stuff.............I am only saying that if you do any of this..........lets do the "right" the first time and not have to do it over..........

I know I am getting ahead of the discussion a lot........but I do not want anyone to do any more work than is needed.............be patient.........we will get there and we will cover every aspect of this method in detail as time goes on..............again, please be understanding of my time available at this time...............

crossbones

 

OK CB2, here is some data. Truck has 249000km, small town driving rarely gets out of 3rd gear and short runs gets about 14 IMP miles/gal. Highway empty truck I have got as good as 22.5-IMP miles/gal. Injectors rebuilt have 7050 km, IP rebuilt has 5000 km fuel filter is 3 weeks old, and aircleaners is older, but clean. No timing tools in area, powerstroke rattle cold advance on powerstroke rattle gone with advance shut off. (ear method works when it has to,LOL)

Indivdual glow plug output in order at idle: 13.1, 12.8, 13.6, 12.8, 12.8, 13.1, 13.3, 13.8

At 1500 rpm (with headers the neighbors would complain if I ran it higher) the individual output in order: 13.5, 14.1, 13.8, 13.5, 13.8, 13.8, 13.8, 14.1.

Wired up at the glow plug lead at the controller, results as follows:
7.4 mv-300egt @ downhill no power; 9.7mv-250-300egt@ normal idle; 14.4mv-400egt @ 3rd town crusing; 16.4mv-500egt@4th level accelerating; 17.4mv- 700egt @ 4th gear engine slow after hill climb; 18.9mv-650egt@kick down to 3rd accellerating; 20.5mv- 700egt@ 2500 kicked down up hill.

You can see from these numbers that the EGT output maintained a parallel relationship to the cumulative mv output of the glow plugs.

 

Very interesting thead, I only wish I checked it out sooner.

I think this is a good example of thinking out side the box, well done crossbones. I have seen a similar idea for tuning a propane powered a engine that still has the 02 sensor in the exhaust. I think your method is definately sound.

If I were to use a digital selfranging voltmeter would that be acceptable? Or would anolog be better?

 

Ok i have read the thread but i am still confused on where you make the connections exactly with this meter, hot goes to what and ground goes to what? I would like to see what numbers my truck is getting, and about working on the injectors and IP i'm afraid to even touch these things i know nothing about these, i know a lot about everything else but the fuel delivery system scares the hell outa me i won't lie, can someone explain all the parts to the injectors, also where would you go to for a rebuilt bosch pump for one of these engines(does bosch even make a rotarty pump for a v8 like we have?) and where does everyone go to get their rebuilt injectors? Thanks much, keep up the work CB2, i'm very interested in this thread

 

Excellent work KJLYPW not only with the glow plug readings, but with the many hours of work on your engine..........you have a well "balance" readings between cylinders......the hours you spent on the injectors paid off...........how dare you cheat with the headers

It's important for everyone to understand that the actual numbers posted may or may not be ideal numbers.................we are looking for the relationship of the numbers to other things........in this case he has a second tool in place for a comparison.........the egt gauge..........

Lets look at exhaust temperature for a second........in order to get a "handle" on what it should be, we must consider a lot of things.............this is not meant to be exact because of the complexity of all things to consider.................

First is that using #2 diesel fuel with regular air that we breath, a ideal Isothermal event should produce about 980°F temperature in the cylinder .................the first thing is to subtract the amount of heat going into the coolant.....say 195°F........now we have 785°F , now we need to figure in the radiant heat loss at the which is about 10% ..say 100°F........now we have 685°F to make "work" for us..........just for kicks, let's shoot for 40+% Efficiency (by the way, what is the efficiency rating of the all mighty Power Stroke)........now if we put 40% to work for us we have 411°F left........for our egt gauge reading....................

Now, let get down............it is stated that a "perfect diesel can be 56% Efficient"...........uumm using the crude math above, I do believe that comes out to about 300°F.............unbelievable.....but wait...................he reported a exhaust temperature of 300°F at idle.....................................if the engine has the proper timing and the proper amount of fuel for the rpm that the engine is running at..................the target exhausts temperature window is say 300-470°F............this does not count acceleration conditions and changing pay loads.....

The glow plug readings and exhaust temperature are in a direct relationship at a steady state rpm and load..................I just find the glow plugs to be faster in response and to be more accurate for my purposes........and I can get info about each cylinder from them.........

As I stated before, at this point, it not the actual number, but the relationship of the numbers.............what we want to achieve is the lowest possible glow plug readings(and exhaust temperatures) at idle as we do at any Steady State RPM and load (level ground as well).................it can be done......I have got as close as .5mv variance from idle to steady state highway speeds (55 MPH , hey I am a old man) on a Isuzu engine...........

keep the reports coming......we can do it.........

crossbones

 

David.....use a digital auto range.......anolog is to slow and hard to read

caterpillar.......hook the ground lead to the block and the positive to the glow plug relay on the glow plug side.....

 

With the mods to my engine I am a long way from you guys.
But the batteries were a little low in my meter.

Cold start advance on 750 RPM - 18mv
Cold just as advance kicks off 650 RPM - 15 mv
195 head temp 650 RPM - 10.2 mv
195 head temp 675 RPM advance on - 14.1 mv

I will try again next weekend.

Depending on the meter you have, if it is manual ranging you may want to unhook it when the glow plugs heat.
Battery voltage may be bad for some meters in the millivolt range.

Lowered compression - 20.25 to 1 base CR
DPS Stage 1 injectors
Cold air intake
ATS turbo - max boost
94 7.3 turbo IP - max fuel
Advanced timing
14,000 miles on complete rebuild

 

82F100SWB,
Where is your thermocouple?

If it is after the turbo you don't want to see much over 800 degrees anyway.
Do you have any black smoke pulling a hill?

 

David........your readings are not that far off from KJ's at idle.......
9.7 versus your 10.2....................

Again, please do not assume that these numbers are either good or bad............

Do not assume that something "must be bad wrong with my engine" if your numbers are very different from these.....

David has mentioned compression ratio................we will get into how the compression ratio is used for different things (like boost)...........but for now,,,,,,, just make a mental note...........what we really want to know is the Effective Compression Ratio..........this number is derived from the actual cranking compression in PSI....example: a cranking compression of 441 PSI is a ECR of 21 to 1...............simply get the square root of 441..............

crossbones

 

macman......absolutely