Diesel Place banner

101 - 120 of 123 Posts

·
Registered
Joined
·
35 Posts
Yes perhaps by saying add 5 he meant add -5?
 

·
Registered
Joined
·
35 Posts
I always figured that if you are using(for example) a CTS for balance rate that it would be figuring in this extra calculation involving the fuel rate. That is unless theferm is the only one who knows of this voodoo balance rate maths stuff
 

·
Registered
Joined
·
22 Posts
question. When doing the calculations, do you add the Pilot injection rate also? The main fuel rate was 4.2. the pilot was .9. does this mean the actual fuel rate was 5.1? or is it still 4.2?
 

·
Registered
Joined
·
7,135 Posts
Discussion Starter #104
question. When doing the calculations, do you add the Pilot injection rate also? The main fuel rate was 4.2. the pilot was .9. does this mean the actual fuel rate was 5.1? or is it still 4.2?
You can add it to it. Pretty sure EFILIVE adds it in as well as a TECH 2.
 

·
Registered
Joined
·
1 Posts
So if I am reading this right and using the numbers from my 2003 LB7:

Raw balance rates from my Insight are

Cyl - mm3
1 - 0.7
2 - -1.3
3 - -2.3
4 - 1.7
5 - -2.0
6 - 4.1
7 - -1.8
8 - 1.0

This would initially lead me to think the number 6 injector is out of specification and potentially the problem.

My main injection rate is 6mm3 and I am at sea level so using 8mm3 I should adjust those rates by 2. Duplicating what was done in the original post gets me:

Cyl - mm3
1 - -1.3
2 - -3.3
3 - -4.3
4 - -0.3
5 - -4.0
6 - 2.1
7 - -3.8
8 - -1.0

Which now tells me the injectors on the passenger side bank are the worst with two being out (3, 5) and one borderline (7).

My truck just the other day had a small white haze coming out of the tail pipe and a diesel smell noticeable. I added a large dose of DK and it has certainly gotten a lot better already but did start me on the education of balance rates. This is my first diesel so I am still learning a lot about the motors.
 

·
Registered
Joined
·
6 Posts
by that method I only have 1 injector at borderline but I get heavy smoke at idle, but only 50% of the time, other times it idles clean.
here are pics of my rates and fuel rates, please correct me if I have done it wrong





 

·
Registered
Joined
·
10 Posts
3rd set of injectors bad?

I'm new to forum not really a mechanic but do turn wrenches. I bought a 2001 Silverado 2500HD Duramax a few years ago. Within 2 months I had 4 injectors replaced. (the other 4 were replaced by previous owner) Within 20k miles smoke out back and was told that I needed to replace 3 injectors, and 2 others are going out. I tore down and sent out injectors to a place in Tx to rebuild. When I got them back and installed still smoked. Balance rates were
-7.81
14.16
-3.71
-0.27
-4.81
-0.73
-1.40
-2.46
Returned injectors to him and he said that he rebuilt them again and all were working fine within specs. I installed the injectors, a Cat fuel filter as well as a marine water separator and filter. I also had a lope in the RPM so I installed a new FPR along with new fuel lines. Now I get a P0093 and truck goes in limp mode. New balance rates
-1.32
-3.24
-3.21
3.08
14.16
-5.66
-5.75
-5.61
I have a predator tuner but am running it stock now. The only other thing I have done is put on a 4 inch exhaust from the turbo down. I can't believe that these injectors are bad again. Truck is idling rough and after it warms up goes into limp mode.
 

·
Registered
Joined
·
2 Posts
2004 injector recall

does anyone know if there was a recall for an 04 Chevrolet Silverado 2500 HD if so how can I find out if the have been done or need done, I just bought the truck in Sept of last year and it's my first diesel and I'm trying to sell it now and everyone keeps asking me if they have been changed.


Thanks
Jimmy
 

·
Registered
Joined
·
6 Posts
jimmythegreek

jimmythegreek 2004 has 2 motor options depending if yours is early or late in the year, check the 8th digit of the vin, if its a 1 you have the lb7 and you can check at a gm dealer if the truck has been done under warranty if it hasn't you can still get it done, if the 8th digit is a 2 then you have the lly and you don't have to worry about the injectors as they don't have the same fail rate as the lb7 does
 

·
Registered
Joined
·
6 Posts
as long as you are within the milage coverage it won't matter if you are the original owner, im not sure if its different in the usa but in canada they can't put a time limitation on stuff like this, if they did charge you i was quoted on my 2002 at $7500 cdn at the dealer, but the bd power shop quoted me $4500cdn for upgraded ones, those are both installed all taxes in.
 

·
Registered
Joined
·
1 Posts
I just replaced 8 injectors that by this math had 3 out the 8 injectors bad and the calculated fuel rate was 5.8mm3. Now the balance rates with new injectors look great with all being +/- .75 or so. the problem I'm having is that my oil level still seems to be increasing and my calculated fuel rate is still right around 5.8mm3. Please advise as to why the fuel rate is still low and what i should look for.
 

·
Registered
Joined
·
27 Posts
I had no idea of correcting the raw figures I saw in the CTS2 Edge, good to know the proper method, although I'm still trying to make full sense of it all.
 

·
Registered
Joined
·
48 Posts
Fuel Rate/Injection PID for Duramax for Torque

To get the actual balance rate of your cylinders, you must know the fuel rate/injection amount at the time the balance rates are taken (this will become VERY clear in a few minutes why you MUST know this number). The engine should be at 170 degrees or hotter, at a normal 680 idle (01 idle at 600, and LMM's idle at 720), rail pressure should be 35MPA for federal LB7's, and 30 MPA for most others, the battery should be charged with no abnormal loads on the engine (IE A/C off), and vehicle speed is 0MPH (the ECm only does balance rates when the engine is idling, and vehicle speed is less than 2 MPH). The fuel rate/injection amount should be at 8-9MM3 of fuel with all of these conditions met (at sea level it is safe to use the 8MM3 of fuel number, at 5000+ feet use the 9MM3 of fuel number. VVT trucks(LLY+) with the turbo closed at idle like in stock tuning will be closer to 9-almost 10MM3 of fuel at idle due to the extra engine load to spin up the turbo at an idle with the veins closed.
I'm using Torque with a Clone ELM OBDII Reader. I have balance rates for Cylinders
1 thru 8:

Cyl 1 = 1.3
Cyl 2 = -2.1
Cyl 3 = 1.5
Cyl 4 = -3.5
Cyl 5 = -2.8
Cyl 6 = 3.0
Cyl 7 = 2.6
Cyl 8 = .1

680 RPM
Temp = 176 Degrees
Fuel Rail = 5008.2 PSI = 35.026 MPA (MPA = PSI / 145.0377)

Fuel Flow = 84.08 cc/min (as read from Torque)

This fuel flow looks incorrect for idle on the Duramax, or it's a value of some
flow that I don't understand. I don't have any other options on the application
Torque to see how much the injectors are really applying in idle.

I'd think it would be ((8 mm3/sec +-the Balance) * 8 Injectors) * 60

If I assume a flow of (6 mm3/sec + maybe 2 mm3/sec per cylinder * 8 ) *60
I'd think the flow would be around (64*60) or 3840 mm3/min or 3.84 cc/min

So, why is the rate showing as 84.08 cc/min? What is the actual PID that
should give the Fuel Rate/Injection?

Is there a way without a Tech 2 to get that Fuel Rate/Injection value?

Thanks for a GREAT posting on Balance rates.

Larry
 

·
Registered
Joined
·
174 Posts
I just replaced 8 injectors that by this math had 3 out the 8 injectors bad and the calculated fuel rate was 5.8mm3. Now the balance rates with new injectors look great with all being +/- .75 or so. the problem I'm having is that my oil level still seems to be increasing and my calculated fuel rate is still right around 5.8mm3. Please advise as to why the fuel rate is still low and what i should look for.
You could STILL have a leak from somewhere other than an injector, e.g. a fuel return line.
 

·
Registered
Joined
·
13 Posts
I'm using Torque with a Clone ELM OBDII Reader. I have balance rates for Cylinders
1 thru 8:

Cyl 1 = 1.3
Cyl 2 = -2.1
Cyl 3 = 1.5
Cyl 4 = -3.5
Cyl 5 = -2.8
Cyl 6 = 3.0
Cyl 7 = 2.6
Cyl 8 = .1

680 RPM
Temp = 176 Degrees
Fuel Rail = 5008.2 PSI = 35.026 MPA (MPA = PSI / 145.0377)

Fuel Flow = 84.08 cc/min (as read from Torque)

This fuel flow looks incorrect for idle on the Duramax, or it's a value of some
flow that I don't understand. I don't have any other options on the application
Torque to see how much the injectors are really applying in idle.

I'd think it would be ((8 mm3/sec +-the Balance) * 8 Injectors) * 60

If I assume a flow of (6 mm3/sec + maybe 2 mm3/sec per cylinder * 8 ) *60
I'd think the flow would be around (64*60) or 3840 mm3/min or 3.84 cc/min

So, why is the rate showing as 84.08 cc/min? What is the actual PID that
should give the Fuel Rate/Injection?

Is there a way without a Tech 2 to get that Fuel Rate/Injection value?

Thanks for a GREAT posting on Balance rates.

Larry


This is exactly what I am having trouble with using torque pro. My rates in park are.


Cyl 1 = 0.2
Cyl 2 = 0.1
Cyl 3 = 0.3
Cyl 4 = -2.3
Cyl 5 = 0.6
Cyl 6 = 3.9
Cyl 7 = -1.3
Cyl 8 = -1.4

680 RPM
Temp = 150 Degrees (I recently cleaned the cooling stack and this is about what it idles at.)
Fuel Rail = 5231.5 PSI

Fuel Flow = 86.9 cc/min (as read from Torque)


I've seen 6 jump up to 4.2 and 4.1 occasionally, it usually runs 3.5 to 3.9 so I thought that one was going out. I'm beginning to this its the only one that's still in spec because...


Earlier in this thread FERMONATOR stated that when the fuel rate drops below about 2.0 the ECM drops all the balance rates to 0 and the engine runs rough. I saw this 3 times today, once sitting at the pump, once in my driveway, and once when dropping the kid off. My guess is that my fuel rate is normally hovering right above 2 mm^3 but occasionally dips down. If that's the case I need to adjust by about 5 mm^3 and my rates will look more like:


Cyl 1 = 0.2..... -4.8
Cyl 2 = 0.1..... -4.9
Cyl 3 = 0.3..... -4.7
Cyl 4 = -2.3.... -7.3
Cyl 5 = 0.6..... -4.4
Cyl 6 = 3.9..... -1.1
Cyl 7 = -1.3.... -6.5
Cyl 8 = -1.4.... -6.4


Of course there is some guessing on my part since I can't see my fuel rate. Does this sound reasonable to anyone? I would really appreciate some input. I have a good shop local, they will hook up their computer for $50. I plan on swapping injectors myself.


FYI the Chevy is at 183K, current injectors were put in at 50k under warranty. I did the injector clean out last night.
 

·
Registered
Joined
·
1 Posts
Searched thread, anyone have the proper PID to check fuel return rate with an efi v2?
Have almost no rail pressure, thinking it's returning too much fuel.
TIA
 
101 - 120 of 123 Posts
Top