Looking 2 diagnose injectors

[Durabroke]

I have a 2001 duramax and it's been to the dealership 4 times. The first time was because I had major injector failure flooding the engine with diesel fuel. In that first time I picked my truck up 4 times never leaving the dealer. Now I have been taking it to another dealership and they seem to have a better diesel mechanic. I've had my truck for a week or so and now I think that i have another bad injector. So will EFILive diagnose a bad injector or high flow rate? And can I turn injectors off one at a time? The reason being, my truck is knocking and I'd like to find out if it's an injector or not. So far I've relied on my ears and I'm starting to dought myself. thanks

[tirekillinss]

just registered to this form today, so if i mess up, don't get mad. most LB7 and LLY injector problems come from the fuel filter and how it is re-assembled after repairs are made, i have worked on these engines from day one, they do not like debris (of anything bigger than 5 micron) past the filter. most aftermarket filters stop 20 micron and larger, oem filters trap 6 micron and larger, as far as measuring for high return rate, as of right now, can only be done by disassembly and attaching hoses and measuring beekers, and not with a scan tool (bad move on GM)........hope this answers at least some of your question.......

[TAQuickness]

moved to Diesel Forum

[GMPX]

Durabroke (pretty sad name really), we cannot shut injectors off, if there is one thing with dealers it always pays to shop around, you will find one soon enough with a good mechanic.
Try calling a few of the GM Diesel Performance shops, I bet they will be able to tell you the answer.

Cheers,
Ross

[DURAtotheMAX]

just registered to this form today, so if i mess up, don't get mad. most LB7 and LLY injector problems come from the fuel filter and how it is re-assembled after repairs are made, i have worked on these engines from day one, they do not like debris (of anything bigger than 5 micron) past the filter. most aftermarket filters stop 20 micron and larger, oem filters trap 6 micron and larger, as far as measuring for high return rate, as of right now, can only be done by disassembly and attaching hoses and measuring beekers, and not with a scan tool (bad move on GM)........hope this answers at least some of your question.......

then what are balance rates for?

the OEM filter traps 6 microns, and is only like 70-something % efficent, even the new dual pleat filter. Every single aftermarket filtration system ive seen (Nicktane, Kennedy Diesel etc...) traps all the way down to 1 or 2 microns, and is 90-something % efficent. Crap in the fuel is NOT what causes the LB7 injectors to fail. I have seen dozens of engines with aftermarket filtration up the wazoo, tons of Stanadyne and they still puke injectors right and left. Then ive seen trucks with NO aftermarket filtration keep injectors good for 150k miles. There is no rhyme or reason to LB7 injector failures. IMO it is a basic design flaw. LLY's dont ever fail injectors....completely different design!!:Eyecrazy:

[tirekillinss]

balance rates tell you what the ecm is trying to do to maintain a steady idle rpm, when i said "aftermarket filters", i was refering to napa, carquest..etc. was unaware other companies filtered that small, yes the LLY is a different design (and a much better engine/fuel system), i have no answer for the frequency of LB7 failures, all i can tell you is what gm tech assist tells me when i call

[DURAtotheMAX]

balance rates tell you what the ecm is trying to do to maintain a steady idle rpm, when i said "aftermarket filters", i was refering to napa, carquest..etc. was unaware other companies filtered that small, yes the LLY is a different design (and a much better engine/fuel system), i have no answer for the frequency of LB7 failures, all i can tell you is what gm tech assist tells me when i call

the availible fuel filters for the Duramax are made by Racor, Racor, Racor, and a few rare hard to find ones are made by Racor.;)


Whether it says Napa, carquest, Uncle Jim's auto parts, whatever...they are all relabled Racor filters and all come from the same place.:D

[tirekillinss]

the reason i said napa or carquest is i have a local tow truck compay with 10 c5500 trucks with LB7 engines, the mechanic at their shop always used carquest filters, i had at least one of their trucks in once a month for 8 fuel injectors(on one truck in particular aprox $15,000.00 worth of injectors,parts and labor) they switch to oem filters, have'nt seen them back for injector problems since(tow truck company, they broke everything else on it though)

[sweetdiesel]

i run a racor r 60 t on my framerail 45000km no probloms yet
ooops shouldnt of said that

[jerjoek]

I have an 02 LB7 that the injectors stuck on and it flooded the crankcase with fuel. The dealer covered the replacement of the injectors under a recall.
Then two weeks later the motor launched. I am now looking to replace it, and GM will not pay.:mad:

[Durabroke]

Well, found a dealer that's a bit better. I do think there's somethink wrong because I only get about 15mpg and the engine sounds rough.