LB7 runs and drives, Doesnt start unless primed. Dealer says injectors

mriley

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Nov 19, 2013
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Might be a long title but thats the story. Ive got a 2003 duramax that runs and drives perfect. a few weeks ago i started it, it ran for 10 seconds than shut itself off. Cranked and cranked it over, wouldnt start back up. I did my research and discovered fuel filter head O rings are prone to failure and cause the stall after start up. Replace those, Replace the fuel filter, and replace the WIF sensor, Still wouldnt start.

Now ive figured out by priming it 2/3 times, than having somebody prime while i crank it over it fires right up and runs great with no issues, i did this and drove 100 flawless miles, however every time i shut it off i must do the same procedure to get it running again. I drove it to the chevy dealership, and they say it needs all new injectors and quote me 4500 for the job. They say the injector return feeds are off (dont remember the exact terminology he used), so they must be replaced. I ask if its just a couple injectors, he says they are all bad, all 8.

Does this sound like bullsh** to anybody else? Truck has 140,000 miles on it, injectors have never been done. No aftermarket air filter, no chips, not even an aftermarket exhaust its entire life.
 

mriley

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Nov 19, 2013
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Also, I have a code scanner and the truck is throwing no codes for injectors. just 2 codes for glow plugs, and EGR valve (Northeast Emissions model)
 

Muff

Just Learning
Oct 7, 2013
1,063
0
36
Butler, Pa
Those year trucks are know for injector failure. The dealer is telling you to replace all 8 because if you just replace 4 or 5 the other 3 will more than likely go bad as well.

The truck doesnt smoke white or any other sypmtoms? Rough idle? Just wont start unless primed?
 

Ne-max

I like turtles
Nov 15, 2011
3,361
64
48
Lincoln, Ne
Sounds legit. Hi return rates means its not creating enough rail pressure to start. Price around the diesel shops in your area for doing the injectors. Just make sure they ONLY use oem ones.
 

lockner13

Member
Aug 17, 2013
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0
6
Have you checked the hoses to and from the filter and ficm? take my advice lightly as I Don't normally work on diesels except for my own but seems to me like it would have to be a problem in the supply system low pressure side like only up to the cp3 since the cp3 draws a vacuum on the lines to pull the fuel up to it then takes that and multiplies pressure to make the line pressure high enough for the system to work properly. I'd start by looking good at the 5 (I think it is) hoses near the filter housing or somewhere around those lines. I'm sure there are many others on here that have a better answer, that's just what comes to mind for me lol. Good luck. I'd do the injectors myself if I were you if it comes down to it. I got em from a dealer here for 1700 and it wasn't bad for me but I work on gas cars all day too.
 

workin' diesel

factory tuned
Nov 13, 2010
630
0
0
Coalhust, AB Canada
I bought my truck 5 years ago and it had 135,000 on it. The injectors were shot. It was still under the 150,000 mile warranty, so I had it done right away at the dealership. It was $4500 at that time too. I wonder if there is still warranty coverage for yours? Maybe they discontinued it.
 

dirtydmax

<---up shit creek
Sep 1, 2013
1,072
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muskoka,Ont Canada
Also check the quick connects on the driver side(2)my main disconnected just enough to pull air but looked ok.Stealer said I needed injectors too.You never know!
 

Max Attitude

11SIX
Mar 7, 2012
814
0
16
Caledonia, MI
I bought my truck 5 years ago and it had 135,000 on it. The injectors were shot. It was still under the 150,000 mile warranty, so I had it done right away at the dealership. It was $4500 at that time too. I wonder if there is still warranty coverage for yours? Maybe they discontinued it.

I believe the warranty was extended on injectors for trucks '01-'03 to 7yrs 200k miles. Whichever comes first. So he would be past 7 yrs.
 

Aaron@LDS

Goin' Broke!
Vendor/Sponsor
Jan 19, 2013
95
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Saint Johnsville, NY
It may be injectors returning too much fuel, but you most likely would have noticed a trend starting to happen. When injectors start returning too much, the first sign is that it will start when cold, but will crank for a long time once the truck is warmed up. The problem generally gets worse. Eventually not starting at all when warm... Then not starting period. Trucks with the return issues do not usually lose prime. So if yours is actually losing prime I doubt your injectors are the cause. Sometimes the Schrader valve will leak causing a prime issue. Just something to check.

If you ever do need injectors, we at Lincoln Diesel Specialties stock OEM Bosch Remans.
 

mriley

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Nov 19, 2013
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The truck idles fine, drives 80mph down the highway on cruise control fine, and shifts fine. a little blueish smoke if the truck idles for too long (20+ minutes) but once you drive it down the highway for a couple minutes that goes away.

Priming it 3 times gets the primer hard and it stays that way, it does not appear to be losing prime. Trust me, i was hoping to get those 20 dollar O-rings on that fuel filter head and be all set...that didnt end up being the case. I knew they needed to be replaced anyways because when i primed it i could see bubbles rising up from where the fuel filter heater wires go into the head.

Im not too mechanically inclined, i can figure certain things out but as soon as i start disconnecting hoses and messing around with ficm and cp3 stuff im sure my problems will get worse.

There are NO diesel shops in my area. none. Before i went to Chevy, I dropped my truck off at Adirondack Truck Repair in glens falls NY, He did the 2 things i already did (installed new O-rings, and installed a new fuel filter) and than spent an additional 6 hours of "diagnosing" at 80 bucks an hour. I left there with 750 dollars less in my pocket, and NO new knowledge as to what the problem could be besides that he was on the phone with a guy at chevy who says it "might be" injectors. I will never go there again for any kind of work.
 

mriley

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Nov 19, 2013
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By the way, this truck is for sale. The day that it quit on me is the day the guy was supposed to come pick it up...ofcourse because why wouldnt that happen right? :mad:. He had already test drove it, loved it, and arranged to purchase it. So now im stuck with a truck i dont want, and a 4500 dollar repair bill that i also dont want.
 

MACKIN

Smell My Finger...
Aug 14, 2006
3,948
1
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Connecticut
As stated you need to see what your return rate is if you are returning to much fuel it wont start.

It is confusing that you pump the primer three times and it starts.Makes me wonder if the check ball in the filter head is allowing the fuel to return to the tank.

You have two options IMO get a second opinion from someone on the return rate or put a lift pump on to eliminate the priming issue for the most part.
 

mriley

New member
Nov 19, 2013
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As stated you need to see what your return rate is if you are returning to much fuel it wont start.

It is confusing that you pump the primer three times and it starts.Makes me wonder if the check ball in the filter head is allowing the fuel to return to the tank.

You have two options IMO get a second opinion from someone on the return rate or put a lift pump on to eliminate the priming issue for the most part.

I was actually going to ask about a lift pump. Im no diesel pro but from what i understand the lift pump eliminates any need for "priming", so maybe i should look into getting one of those? I picked it up from the chevy dealership today and drove it home, tomorrow ill be driving it to connecticut where my family lives and theres alot more local diesel shops. Its just hard for me to believe that i can do hundreds of miles of driving with it running fine, and it needing injectors.
 

mriley

New member
Nov 19, 2013
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That does look like a clean truck. How much would you want for it as is?

It absolutely is one of the cleanest early duramaxes around (up north anyway), before it started acting up i had a guy who had withdrawn 15 grand from his bank to come pick the truck up. The morning he shows up is when this problem started, go figure. As it sits now i believe its worth 12,500 to the right person