New injectors again...

[MaxACL]

My engine is smoking….again and the mech scan tool gave the following injector readings:

#1 -2.1
2 3.4
3 -0.8
4 -2.6
5 2.1
6 -2.6
7 4.8
8 -2.6

The mech wants to try a diesel cleaning procedure from BG company and I’m inclined to agree.

We’ll know soon whether or how much it helped. My question is this:

The injectors that’s in there now is the 7th (seventh) set in 6 years. Warranty covered five of them and I paid for the other two at about $3,200 each set. Now it looks like set number eight is just over the horizon. What am I doing wrong? I always fill at high traffic truck stops, I keep good fuel filters in it and I use a good fuel supplement with each fill. Some body help!

It’s an ’02 GMC LB7 with 325,000 mostly highway miles.

For a while it has also had a P1093 code… low fuel pressure? Could the pump be coming apart?

Mike

[Mark Rinker]

Wow. For comparison:

2002 Chevrolet LB7, 280K miles on second set of injectors. First set replaced at 170K. Fuel up anywhere. Occasionally dump in fuel additives of various brands when I feel guilty. Maybe once in every 10 tanks. Maybe less. Rarely.

I was experiencing some mild smoke at idle, cleared it up with 1qt ATF per tank fill (approx 1:120 ratio) over 4 or 5 tankfuls. Today I noticed it was starting to return, after 2 or 3 tanks without. My plan is to run this set until it starts making oil, or develops a fuel knock. Let it smoke.

I wonder if GMC did something different in the fuel system - i.e. tank material, fuel cooler, fuel lines, injector pump...?

Last thought - have they been replacing the injector LINES each time? The first set I had were very corroded at the flare nuts (Minnesota road salt finds its way everywhere) so we installed a brand new set (purchased for cheap, brand new OEM on Ebay, rather than the $1000 set GM wanted to sell me!) and GE-sealed the flare to line area per GM warranty repair instructions. The risk of re-using corroded lines is rust or whitish corrosion might find its way into a brand new injector - during installation.

Good luck. I would have lost my mind by now if I was trying to run a business and replacing injectors at that rate. Lemon law?

[Mark Rinker]

Um...I just re-read your post...carefully, looking for ANYTHING that was unique to your use, over mine.

You add a 'good fuel supplement' every tankful.


What are you running???

[SoTxPollock]

MaxACL, I suggest an additional Racor RS60S which filters down to about 2 microns. Truly believe the answer is additional fuel filtration so that the injectors see only super clean fuel.
Also believe injectors should absolutely not see full fuel flow at low temperatures, but should be at normal operating temperature before you floor it.

[MaxACL]

Mark,

I use Standyne when I can find it, FPPF and PS otherwise. Never thought about the lines.

SoTex,

I had a Racor under the truck for several years (2 micron). When one of the set of injectors was replaced, someone bent the fuel line backwards and crimped it at the fire wall. Ordered a replacement from GM thinking it was restricting the flow. The new line arrived in a large box but it too was bent over double to fit the box. Wouldn't you know it.... it was crimped in the same place. I didn't replace the filter because of time constraints and I was still having the problem.

The BG cleaner worked good but the problem is still there.

Mike

[Mark Rinker]

I am simply looking at this from all possible angles, since your failure rate is so out of range with what might be considered 'normal'.

There must be a common thread with this many failures over such a relatively short period of time, and miles.

Has anyone retained/inspected the injectors for a root cause? Same dealership? Same mechanic?

[Jake99Z71]

I had 3 sets in less than 20K miles. I ran the stock filter for 10k miles before changing. I installed the Racor RS90S with Kennedy Twin lift pump around 17k miles. Changed this filter every 20K miles. I also ran PS for the first 20K miles then switched to Soy Shield. The first set were at 98K miles. After the third set I got rid of the truck.

[MaxACL]

I still have an old set of injectors in the garage from two changes ago. Could one of those be inspected? And what exactly breaks in these? Could it be a stray current that doesn't show up on the code list?

They have been changed at different dealers or shops nation wide... the only common demonator I can see is that I do use a supplement. No long idles at rest stops, no cheep fuels and I always vote Republican.

Anybody want the old set for a core someday?

Mike

[Steveesp52]

You talk about your truck smoking. When does this happen? I'm not sure I'd be looking at the balance rates for this and jump into throwing another set of injectors at it. They don't seam that far off and they cost a bunch.

I've got an '04 with 196K. Injectors replaced probably around 80K. Previous owner was chasing a surge at idle and replaced almost everything on the truck. I bought it at 138K with the problem still there. Watched the fuel pressure during the test drive and it sure had a regularly fluctuating actual vs commanded pressure at idle. I wish I had the injector balance rates from the truck when I had that problem so I could use that info now. I do notice when I run injector cleaner through the truck, I get worse fuel economy, about 1 mpg. I noticed this with my old 6.5 TD as well. I sure can't figure out why I have seen this but I also use the gallons pumped vs mileage calculation. I don't believe the DIC for figuring Avg MPG.

Are you noticing any other problems with the truck? or is the dealer telling you the injector balance rates are causing the problem. Again, I'd probably look at some other stuff before condeming yet another set of injectors especially if you are paying for it. I have often wondered how the injectors cover up other problems. They are expensive and don't frequently go bad that quickly unless you have bad fuel/water.

When you say smoke, I have not noticed smoke from my truck and my balance rates have been as high as +10 and -7 recently on #3 and #7. #5 use to be high but is OK now. I occasionally notice some belt squeek at idle from the rough run but the belt has also never been changed. No misfire codes yet either. I am setting EGR codes P0401, P0404, P1404 so will need to fix that. Probably carbon in the cooler and EGR.

The ECM monitors Crank rotation speed for the balance rates I think. I'm also thinking I'll put a new belt on the truck to see if that changes the balance rates. Long shot but the belt is due anyway.

Do you notice if the DIC Avg MPG is as accurate as it use to be? I'm chasing a new problem where my DIC avg MPG has jumped from 16 to 19-23 lately but still no change in how the truck runs. Actual Avg MPG lately has dropped from 15.5 to 14.7 so I'm sure something is going on. Trying to figure out which part to go after first. Fuel pressure sensor seams to be the first in my mind. With the price of Injectors, and being out of warranty, I'm not going there first even though I'd do the job myself.

Good luck.

[Steveesp52]

Just noticed in your sig that you have an aux tank. Do you have a good water separator. I've heard the factory filter does not do a great job in getting the water out. If you are running a lift pump, you may be churning up the water in the fuel where the factory filter is not effective. If you have water in the fuel, you might be taking out the injectors with rust and your high pressure pump may be next.

Do look at the other sensors. Also have the dealer plot the Actual vs Commanded fuel pressure at idle. They will need to zoom in and reset the max and min values to catch the fluctuating. I think when I had my problem, the fuel pressure would surge 1200-1500 psi at idle. Almost to the point of spinning the wheels on an ice covered road. Idling and riding the brakes with vehicle speed under 1-2 mph. Barely rolling and you could feel it. Also hear it in the exhaust.

[Mark Rinker]

>>> They have been changed at different dealers or shops nation wide... the only common demonator I can see is that I do use a supplement. No long idles at rest stops, no cheep fuels and I always vote Republican



Mike - try voting Democrat this election, and we'll see if your injectors last longer. I am pretty sure you could get some politician to make that promise! :D


My C4500 goes in for a new set of eight injectors (under warranty) next week. #7 is the culprit. It was showing a -4.3 at idle. Engine would create and hold good fuel rail pressure at idle, just lots of smoke at idle and first acceleration after idling

[Dustdevil1]

Truck is in the dealer right now with what I expected is an injector problem. Third replacement. First set in at 44k miles. Second set at 59k. It is now 114k miles. I have used a Nicktane 2micron Cat filter since the first replacement, as well as religious use of Stanadyne Performance Formula. Only other mod is a K&N air filter.
First two replacements were under warranty. This one has been denied. This is a 2003 LB7. So, it's almost 10 years old, but only 114k miles. After making the case with the dealer, the District Specialist, and being told by that dealer that the truck is exceptionally well taken care of, the decision is that GM will cover 15% of the cost, even after I just had the dealer replace the EGR system and vacuum pump to the tune of $1000, and paying $93 for the diagnosis. So, my injector job would cost $4300, and I would get the very same sort of injectors I've had all along. Rebuilt with the chrome plated seat and ball. Not sure I am interested in that. Might do them myself, but not certain I want to take responsibility for installed balance rates after the job is done. Three questions;
1. Is there an appeals process for GM to reconsider dropping any warranty responsibility for the third replacement on the same vehicle for an owner who has owned 12 GM vehicles over the years?
2. Would the Calif lemon law apply to this vehicle?
3. Where would you recommend I get a balance rate report after I reassemble the engine with new sleeves, injectors, and fuel lines?
Oh, and are there any new developments for more reliable injectors than the rebuilt units with chromed parts?

[DmaxMaverick]

Truck is in the dealer right now with what I expected is an injector problem. Third replacement. First set in at 44k miles. Second set at 59k. It is now 114k miles. I have used a Nicktane 2micron Cat filter since the first replacement, as well as religious use of Stanadyne Performance Formula. Only other mod is a K&N air filter.
First two replacements were under warranty. This one has been denied. This is a 2003 LB7. So, it's almost 10 years old, but only 114k miles. After making the case with the dealer, the District Specialist, and being told by that dealer that the truck is exceptionally well taken care of, the decision is that GM will cover 15% of the cost, even after I just had the dealer replace the EGR system and vacuum pump to the tune of $1000, and paying $93 for the diagnosis. So, my injector job would cost $4300, and I would get the very same sort of injectors I've had all along. Rebuilt with the chrome plated seat and ball. Not sure I am interested in that. Might do them myself, but not certain I want to take responsibility for installed balance rates after the job is done. Three questions;
1. Is there an appeals process for GM to reconsider dropping any warranty responsibility for the third replacement on the same vehicle for an owner who has owned 12 GM vehicles over the years?
2. Would the Calif lemon law apply to this vehicle?
3. Where would you recommend I get a balance rate report after I reassemble the engine with new sleeves, injectors, and fuel lines?
Oh, and are there any new developments for more reliable injectors than the rebuilt units with chromed parts?

Welcome aboard!

We have a GM Customer Service representative on board. It may be a good idea to start your own thread, and maybe get their attention a little quicker. Just repost your information above into a new thread, or I can move it. Let me know your preference.

[Dustdevil1]

OK. Thanks DMax Maverick. I've actually been here for 6 or 7 years under the name Dustdevil. But my old acct was under a defunct email address, and I was too lazy to request a reset. I will take that advice, and any other advice I can get. Thinking about tackling this myself. Its not a daily driver, so I can take my time and get it right. My only issue is testing for balance after reassembly. Cheers!

[DmaxMaverick]

You're welcome, no problem. Let me know if you'd like to straighten out your old account before you get too deep into this issue. No biggie if you don't. Your choice. Contact me by email with a reply about that if you want. Once we get all this figured out, I'll delete the posts.

[Mark Rinker]

truck is in the dealer right now with what i expected is an injector problem. Third replacement. First set in at 44k miles. Second set at 59k. It is now 114k miles. I have used a nicktane 2micron cat filter since the first replacement, as well as religious use of stanadyne performance formula. Only other mod is a k&n air filter.
First two replacements were under warranty. This one has been denied. This is a 2003 lb7. So, it's almost 10 years old, but only 114k miles. After making the case with the dealer, the district specialist, and being told by that dealer that the truck is exceptionally well taken care of, the decision is that gm will cover 15% of the cost, even after i just had the dealer replace the egr system and vacuum pump to the tune of $1000, and paying $93 for the diagnosis. So, my injector job would cost $4300, and i would get the very same sort of injectors i've had all along. Rebuilt with the chrome plated seat and ball. Not sure i am interested in that. Might do them myself, but not certain i want to take responsibility for installed balance rates after the job is done. Three questions;
1. Is there an appeals process for gm to reconsider dropping any warranty responsibility for the third replacement on the same vehicle for an owner who has owned 12 gm vehicles over the years?
2. Would the calif lemon law apply to this vehicle?
3. Where would you recommend i get a balance rate report after i reassemble the engine with new sleeves, injectors, and fuel lines?
Oh, and are there any new developments for more reliable injectors than the rebuilt units with chromed parts?


where are you pumping your fuel

[Dustdevil1]

The truck is often used for travel. So, the fuel comes from a wide range of companies and locations, most of which are between Orange County and towns in the Mojave Desert. The majority would likely be stations owned, operated, or franchised from G&M, Shell Oil, Flying J, Pilot, or Chevron. Most of these stations are not in two-bit ghost towns, but usually at pretty busy truck stops, freeway interchanges, larger desert towns (Barstow Ca or Ehrenberg Az, for example), and at busy intersections in and around SoCal.

[GM Customer Service]

Truck is in the dealer right now with what I expected is an injector problem. Third replacement. First set in at 44k miles. Second set at 59k. It is now 114k miles. I have used a Nicktane 2micron Cat filter since the first replacement, as well as religious use of Stanadyne Performance Formula. Only other mod is a K&N air filter.
First two replacements were under warranty. This one has been denied. This is a 2003 LB7. So, it's almost 10 years old, but only 114k miles. After making the case with the dealer, the District Specialist, and being told by that dealer that the truck is exceptionally well taken care of, the decision is that GM will cover 15% of the cost, even after I just had the dealer replace the EGR system and vacuum pump to the tune of $1000, and paying $93 for the diagnosis. So, my injector job would cost $4300, and I would get the very same sort of injectors I've had all along. Rebuilt with the chrome plated seat and ball. Not sure I am interested in that. Might do them myself, but not certain I want to take responsibility for installed balance rates after the job is done. Three questions;
1. Is there an appeals process for GM to reconsider dropping any warranty responsibility for the third replacement on the same vehicle for an owner who has owned 12 GM vehicles over the years?
2. Would the Calif lemon law apply to this vehicle?
3. Where would you recommend I get a balance rate report after I reassemble the engine with new sleeves, injectors, and fuel lines?
Oh, and are there any new developments for more reliable injectors than the rebuilt units with chromed parts?


I can check out your case if you would like. Just send me a message with the case number!

Brandon
GM Customer Service

[Dustdevil1]

Thanks, Brandon. Just sent you a pm.