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Just how bad are these injector rates?

1796 Views 18 Replies 10 Participants Last post by  [email protected]
1 @ 3.5
2 @ 2.1
3 @ 2.1
4 @ 0.4
5 @ 2.3
6 @ 15 (not 1.5, but 15)
7 @ 5.4
8 @ 4.8
#6 code showing PO306C
warm at idle, in neutral.
1 - 19 of 19 Posts
WOW 15:eek:. They should be between -4 mm³ and +4 mm³ at idle, and -6 mm³ and +6 mm³ in drive(according to GM). Its not looking good.-:t

From here I would say 3 possible 4.:uhoh2:
balance rate of 15 can signify an electrical problem or internal mechanical problem...not necessarilly a bad injector.

does the oil smell like diesel?
Look at 7 and 8. What does the oil pressure read? Do you have any over-boost codes?
mvnvltn;1545017; said:
Look at 7 and 8. What does the oil pressure read? Do you have any over-boost codes?
oil pressure is excellent, no overboost code, just the code I previously mentioned, no fuel in oil.
Do a compression test the injector will pegg out @ 15 when the cylinder is dead. I have one in the shop right now that the injector failed, the customer keep going pulling a big trailer he ended up melting the piston and then the glow plug tip broke off and went throug the valve. Bad news but this is just worst case
Good luck
Tell us a little more if you can. Is it running rough? Any Smoke? I bent a pushrod once and it had the same inj bal as yours. Filling out your sig will give the experts here more info about your truck and they can offer more advice. Hope it's not serious.
Give us the + & - also.;)
02freighttrain;1545966; said:
Tell us a little more if you can. Is it running rough? Any Smoke? I bent a pushrod once and it had the same inj bal as yours. Filling out your sig will give the experts here more info about your truck and they can offer more advice. Hope it's not serious.
Actually 02, it runs very smooth, no obvious signs of a dead cylinder. This is what had me confused when the tech informed me of the #6 code description. The truck is an 03, K&N intake, 4" banks exhaust, no tuner now, It's a "burger cruiser," no hot rod here ;-). I had the edge shut down on the EZ, long before this started. Level 2 was the highest it was ever set. 99,970 miles. Fuel filter changed every 5,000 miles (no lie) because I travel from NC to Baja, and am aware of the injector issues others have had. No codes other than the po306c. fuel pressure tested showed 4K+ @ idle (tech quote). Oil changed religiously every 3,000 miles, maintenance has always been a strong point for me, this is a big investment I'd like to last. I've used additives, Lucas fuel treatment. Egt's have never been above 1250, ever, and the 1250 was in a towing situation, light throttle. I honestly do not hammer this ride, it's my livelihood. I'm going to have to think no as far as valvetrain damages are concerned, I would believe there would be an obvious miss present. At this point, there is no fuel in the oil, mileage is ok, power however is hit and miss. Light sporadic smoking at idle has turned into constant smoking at idle now, just yesterday it was off and on. This is why I took the initial respondent's post seriously enough to have a balance check. On a side note, does the book actually show an 8 hour replacement time figure? Also, how would the cylinder be accessed for a compression test, as one poster mentioned?
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dieselfanatic

po306 on your truck is most likely due to #6 injecter leaking too much fuel into the cylinder-especially if you are getting white smoke. using a
scan tool such as a tech 2 at a dealer a tech can cancel cylinders to see
if smoking stops-if smoking stops with #6 fuel injecter cancelled injecter is
cause of misfire and smoking concern. also many times misfire is light and
can be best felt at tip in throttle. would highly suggest to perform compression test on all cylinders and compare. compression test is
performed by removal of all glow plugs and disable of fuel system. will need
correct adapter and compression gauge-should see 300psi on gauge.
good luck hope this helps.
scottlb7;1546233; said:
po306 on your truck is most likely due to #6 injecter leaking too much fuel into the cylinder-especially if you are getting white smoke. using a
scan tool such as a tech 2 at a dealer a tech can cancel cylinders to see
if smoking stops-if smoking stops with #6 fuel injecter cancelled injecter is
cause of misfire and smoking concern. also many times misfire is light and
can be best felt at tip in throttle. would highly suggest to perform compression test on all cylinders and compare. compression test is
performed by removal of all glow plugs and disable of fuel system. will need
correct adapter and compression gauge-should see 300psi on gauge.
good luck hope this helps.
What Scott said........ Your probably gonna get a waranty set of injectors out of this problem. Suck's to have your truck down but it's typical for the LB7's. I'm on my third set:eek: No pressure build-up in the cooling system, is there?
Mine was identical to this, even the #6 cyl. My truck idled like a kitten and had power. #6 cyl was gone.

Good luck.
02freighttrain;1546539; said:
What Scott said........ Your probably gonna get a waranty set of injectors out of this problem. Suck's to have your truck down but it's typical for the LB7's. I'm on my third set:eek: No pressure build-up in the cooling system, is there?
Cooling system seems fine, no overflow or pressure rise / spike. I spoke with the local dealer yesterday, eve. the writer suggested I bring the vehicle in, said it sounds like an injector failure. We'll see. Thank you all for responding, I appreciate it. I'll post a follow up as well.
Just returned back from the dealership, a good experience. They have ordered replacement injectors (all 8) and concurred the balance findings, although #6 was showing a good reading, number 3 took its place when put in gear. They have to be ordered, 1.5 - 2 weeks ETA, no problem. The tech had mentioned the replacements are rebuilt, which I could care less about, and they are also redesigned internally as far as the "rebuild" goes. He also stated he was very surprised they were able to reach 100K. There were no gripes about intake, exhaust, a previous tune, lift, etc. It went very nicely. I feel for others having a hard time getting things handled smoothly.
They should give you a rental too if you need one. I got one with my injector change.
u00bse1;1546748; said:
Mine was identical to this, even the #6 cyl. My truck idled like a kitten and had power. #6 cyl was gone.

Good luck.
Can you explain what exactly you meant by "#6 cyl. was gone"?

Thanks...
MaxRock
nay6;1547509; said:
They should give you a rental too if you need one. I got one with my injector change.
I'm thrilled not having to go through what other people have, they offered a reduced rate for a rental, which is fine. As far as I'm concerned, as long as the repairs are made competently, and the dealer stays "up front," I'm happy. Again, thanks for the excellent replies, and solid advice!!
I'm thrilled not having to go through what other people have, they offered a reduced rate for a rental, which is fine. As far as I'm concerned, as long as the repairs are made competently, and the dealer stays "up front," I'm happy. Again, thanks for the excellent replies, and solid advice!!
:phatyo:
[email protected];1547765; said:
I'm thrilled not having to go through what other people have, they offered a reduced rate for a rental, which is fine. As far as I'm concerned, as long as the repairs are made competently, and the dealer stays "up front," I'm happy. Again, thanks for the excellent replies, and solid advice!!
Seems I spoke too soon on this. After being told the injectors were in, and bringing the vehicle in after the appointment process, the vehicle is sitting, untouched, 5 days later. Why? Because the injectors are not in, the person who made the statement apparently never worked there........and after the service manager received my vehicle, stating how surprised she was at my "niceness", and guaranteeing it would be ready tuesday at the latest.......today, I now am told they do not know when any injectors can be had......I hate being lied to. Randy Marion gets my vote for "Too many chiefs, and not enough indians." So much for staying "Up front."
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