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View Full Version : Proper test procedure for the LB7 Injector?



duramaxjoe
08-03-2009, 17:56
Hi all. I will appologize in advance for the long winded post.

I have done as much research as I thought I possibly could, but I have a dilema that I need edjucate myself on, and hopefully some of you can chime in with some help.
I have a 2002 GMC 2500hd with 46xxx miles on it (low mileage, part time driver :D). Couple of weeks ago, I had ventured on to a small road trip with my 5th wheel tow hauler trailer weighing about 10k. I noticed horrible mileage at about 7.5 mpg. I used to get about 12 with the same trailer but a heavier load at about 13k. I also noticed really hard starting while warm. It would take about 6-7 seconds before it would start. And last problem was lack of power. The pulling power was significantly lower then before.

Long story short, I took my VIN to the dealer to see if I was still in the 7 year/200k warranty because I suspected injectors. The service date expired 1.5 months prior and the GMC dealer said GM wont touch it with a 10' pole. So I called GM customer service to see if they would be willing to work with me since my mileage was so low. The say no. Ok, so I revert to me extended service warranty that purchased when I bought the truck (I bought it used in '03 with 8k on the clock), I have untill Feb of 2010 left on it. The GMC dealer performed the test (dont know what test??) that showed the adjuster person 119 MAPA, and I guess it needs to be at least 158 MAPA, right? The adjuster guy told my service advisor "Ok, yep looks like injectors". But the guy sitting behind the desk at the warranty place (United Car Care) said the dealership did not show the actual failed part(s) therfore the warranty work is denied. WTF, now I am getting pissed as I feel like I am getting the run around from everybody. So, the warranty service advisor says there is another simple way to test the injectors before you dig into the valve covers, etc. My dealer is saying the only other way is a 16 hour tear down then only a visual inspection is all else we can do.

My question is......What is the proper way to show each failed injector? My dealer is telling me that the test he performed is the same test GM does for the special coverage warranty, but the outside warranty company is requesting something other then what GM does. In the meantime, my truck has been there for 2 weeks now with out a darn thing done to it. Hopefully some of you can shed some light on this subject. THANK YOU!!!!

More Power
08-04-2009, 13:59
The tests involve measuring the fuel-rail pressures at various engine rpms, then comparing that data with what the vehicle computer is commanding (actual vs commanded). The measurements are in MPa, which can be read using a Tech II Scan tool.

In addition, the dealer or other tech can compare injector fuel rates between the 8 injectors using a Tech II Scan tool.

And, they can actually measure injector fuel return flows. This last test is not an electronic test - it requires removing the upper valve cover and attaching a series of volumetric cylinders to each fuel injector's fuel-return fitting, then measure actual fuel-return flow over a specific time frame.

The data collected from the sum total of these tests should provide for a conclusive diagnosis. I don't know of anyone who can "look" at an injector, and tell whether it's good or bad (for nearly all types of failures).

Jim

duramaxjoe
08-04-2009, 17:28
OK, I got the data from the dealer, it shows the driver side at 25ml and the passenger side at 18ml. Now the problem is the EFF'N warranty people are telling me that my aftermarket exhaust is why they are denying the claim. I have a Banks Monster exhaust from the down pipe back. The manifolds, turbo and the down pipe itself are all stock. The rest of everything else on or around the engine is completely stock. Is it possible to have a change in back pressure cause these injectors to fail? Or are these people really trying to blow smoke up my ass??? Does'nt the Magnuson Act say that if the aftermarket part is leagl in my state, then it will not void any warranty? PLEASE HELP, I want my truck back!!

DmaxMaverick
08-04-2009, 20:51
An aftermarket exhaust system, in and of itself, will not, and cannot, cause injector failure. Yeah....They're blowing smoke.

The Magnuson-Moss act protects consumers from warranty denials for modifications not related to a failure. The M-M act could help you, in this case. However, like many/most dealerships, your warranty provider will assume, because you have an aftermarket exhaust system, you must also be using other power enhancing modifications that would be related to the failure. It is a blanket assumption, and nearly all of them use it. And, in many if not most cases, they are right. It's up to you to appeal and convince them otherwise. Also, none of this has anything to do with what is legal, or not legal, in any state. That's between you and the state. State and federal laws make it unlawful for any dealer or repair shop to unlawfully modify a legal , or repair any illegal, mandated emission system, if the vehicle may be used on highways or public lands. There are exceptions and exemptions to this, but you and I are not one of them (applies to the military, some government, and some special use vehicles).

duramaxjoe
08-04-2009, 21:16
I thought the same thing that an exhaust system has nothing to do with the injectors. They keep saying that because of the "Direct Injection" and the "Overlap", a different flowing exhaust can cause a change of pressure in the combustion chamber causing the injectors to stress. I know they are full of ****, but they are not willing to do any further negotiating. I have mentioned the MM Act, but they throw out some slang language that does not make sense to me. I know that is their intent. So, I am just doing as much homework as possible so I have more and more confidence every time I call them back. I will not give up. I feel that I have a legitimate claim that needs to be repaired under warranty.

DmaxMaverick
08-04-2009, 21:54
It's hogwash, but if any "stress" were involved, it would be less with a free(er) flowing system. They are doing what keeps them in the money: Taking your money, and not giving you any back. Review your contract very carefully. Look for specifics, namely where it states an aftermarket exhaust system will deny a claim for injector repair, or any repair, for that matter. Also look for a clause allowing for a refund (mandated by some states) in cases of unresolved arbitration/mediation. If such a clause applies, they may use it against you for a lower settlement. Very common.

1. Strong language. Be perfectly clear you intend for them to uphold their contractual agreement.

2. Stronger language, threat of BBB and/or legal action.

3. Better Business Bureau.

4. Small claims court.

5. Civil action court.

I suggest, at this point, any communication you have with them is through the mail. Copied, witnessed, and registered/certified with return receipt (it won't be as credible in a court proceeding if not). I have extensive experience in areas such as this (unfortunately). If you need some [non-professional] advice, please email me with more details. I can't do anything for you, but I may be able to get you in touch with those who can, or suggest an effective course of action.

madmatt
08-05-2009, 07:58
Where are you down at?? GM can offer goodwill,, we do it all the time here for people barely out on time but have low milage. Also I'm pretty sure MM only applies to original factory warranty and not the 5yr/100k "Limited" powertrain warranty and aftermarket deals because the factory only has to by law offer XXX amount of warranty.

duramaxjoe
08-05-2009, 17:33
It's hogwash, but if any "stress" were involved, it would be less with a free(er) flowing system. They are doing what keeps them in the money: Taking your money, and not giving you any back. Review your contract very carefully. Look for specifics, namely where it states an aftermarket exhaust system will deny a claim for injector repair, or any repair, for that matter. Also look for a clause allowing for a refund (mandated by some states) in cases of unresolved arbitration/mediation. If such a clause applies, they may use it against you for a lower settlement. Very common.

1. Strong language. Be perfectly clear you intend for them to uphold their contractual agreement.

2. Stronger language, threat of BBB and/or legal action.

3. Better Business Bureau.

4. Small claims court.

5. Civil action court.

I suggest, at this point, any communication you have with them is through the mail. Copied, witnessed, and registered/certified with return receipt (it won't be as credible in a court proceeding if not). I have extensive experience in areas such as this (unfortunately). If you need some [non-professional] advice, please email me with more details. I can't do anything for you, but I may be able to get you in touch with those who can, or suggest an effective course of action.


The only thing my contract reads in regards to this is

"loss caused modification and/or alteration to the vehicle not provided or specified by the manufacturer. This includes the repair and/or replacement of parts which do not meet or exceed the manufactures specifications."

Key words here are "LOSS CAUSED BY" This is strickly a matter of interpretation (sp?)

duramaxjoe
08-05-2009, 17:36
Where are you down at?? GM can offer goodwill,, we do it all the time here for people barely out on time but have low milage. Also I'm pretty sure MM only applies to original factory warranty and not the 5yr/100k "Limited" powertrain warranty and aftermarket deals because the factory only has to by law offer XXX amount of warranty.

My truck is at Dutton GMC in Riverside, Ca. They seem like they are not willing to lift a finger, but I am in for two tests now with them. If I can get the warranty to step up, then my $100 deductable applies. Is there anything you can do to help me out? Thanks.

madmatt
08-06-2009, 05:55
I'd suggest talking to your regular dealer and getting in touch with the AVM in both your home and this dealer's areas. I'm not sure why so many dealers are against offering goodwill on common failures barely out of warranty. It doesn't pay any less then normal warranty work and I'm sure they do that all day long.

duramaxjoe
08-06-2009, 18:07
I bought the truck used from a small independent dealer, so no help there. I am seeking legal advice now, should know more in the next couple of days.

mattb5150
08-06-2009, 20:59
Who's the aftermarket warranty company? Just curious.

Matt

duramaxjoe
08-06-2009, 21:03
United Car Care

duramaxjoe
08-06-2009, 21:04
http://www.unitedcarcare.com/

madmatt
08-07-2009, 14:01
I went through a similar instance with a aftermarket warr company here on injectors. Warrany book said major engine componets were covered. Called in the injectorjob and their response was that meant (and it did say in fine print) internally lubricated parts. My reponse was " sound like the injectors should be covered then". Then then said they weren't lubricated in which I procedded to tell them of course they were, just by fuel and not oil. Long story short, I got no where with them and the customer is out driving around taking care of our mesquito problem currently.

duramaxjoe
08-07-2009, 14:40
That sucks. My warranty actually specifies "Injectors" (with many other parts), that is the reason why they fall back on the aftermarket exhaust, they have nothing else. Even then, the exhaust thing does not even clear them, so, one way or another, they will fix my truck.

duramaxjoe
09-18-2009, 07:41
Just to follow up.....

I give GM a huge THUMBS UP for stepping up and taking care of my injectors on their dime!! I will remain a loyal GM customer.

Duramaster
09-18-2009, 20:04
Thank you Duramaxjoe! :) My future as a GMC technician depends on "YOU" (and the rest of you GM owners). Without you GM owners I would soon be with out a job! :)

Big Green
09-22-2009, 04:48
The other folks you might talk to are the nice people at Banks. I've heard that they have gotten involved from time to time in BS denials like yours since it gives their product a bad name as well.

Good luck