big injector problem! !
 

OK hello everyone. I'm new to the site and have a huge problem. I am a mechanic with my own small shop in ft worth, tx. I am currently working on a completely stock 2002 lb7. It has 220k on the clock and a grandpa drives it. It came in due to smoking [white] and loss of power. I hooked up scanner and read balance rates to find 2 injectors completely bad, 2 more border line and 2 more well on their way out. So I told the customer let's get a set of injectors and a fuel filter and fix this for good. The old man was on a budget so I bought 8 remaned bosch injectors from Diesel Care and Performance in Tennessee. They come in and actually look great and packaged great. I get them installed and fire it up. Idling smooth and no smoke so I'm happy, until i go to drive off. Immediately notice and bad miss and fuel knock. Kill it reset ecm and fire it back up. Misses at idle, and fuel knocks very bad. No power at all under 2500 rpm. But the smoke is gone lol. I hook up scanner and new injectors are insane. Here are my balance rates.

Cyl. 1 15.0
Cyl.2 8.5
Cyl.3 4.6
Cyl.4. 0.2
Cyl.5. -7.0
Cyl.6. -7.0
Cyl. 7 -7.0
Cyl. 8 -7.0
calculated fuel rate 17.3 mm3.

So if anyone here understands balance rates please chime in. I'm lost. The company has sent out a new set but I'm worried to waste my time again. Thanks in advance

i hate to say it but your best bet is probably going to be to get a set of OEMs i got mine from Merchant Automotive Lincoln diesel parts is good and alligator performance,
looks to me like you found another "pinsacola diesel" type place they are junk looks like Cly.4 is the only one in spec:ouch:

Yes your right but I'm confused at this point for a couple different reasons. First. If you notice the calculated fuel rate, it is very high and that changes balance rate values. Another thing is +15 and -7 are maximum values. So really? 6 injectors bosch remans at max value, something is funny about that. And last, the old injectors were much more in spec than these and the calculated fuel rate was much lower with the old ones. I'm just so confused. Looks like I just gotta tear it down again. They won't do a refund and I can't just eat a thousand bucks like that.

If that company does it like Pensacola diesel they rebuild them in house and they aren't true bosh remans mine are bosh remans from bosh threw merchant automotive when knock off shop try to reman them in house they can't get the tolerances right and it makes the pos from the get go when dealing with LB7 injectors you always have to make sure they came from bosh I hope you this worked out sometimes you can get strange readings if the injectors harnesses are messed up I would check them with a ohm meter while you have it torn down

Yes can't stress enough on aftermarket rebuilds they're junk especially Pensacola and diesel care extremely bad reputation. Return them and try like hell to get a refund even though there is a warranty they'll fight with ya buy from merchant auto boshs and do the cat fuel filter upgrade and that customer will be so happy he will come back to you for everything. Best of luck as I'm sure he won't be a happy camper:tu:

Oh and avoid injectors direct as well but just seen they won't do a refund guess that leaves you with having to exchange give em negative feedback for sure though I only buy factory remans or tested used depending on customers budget.

Worst case scenario put old back in run gm injector cleaner see if that gets originals in specs then see if diesel care will give store credit....idk what a headache just trying to help..

Well I would love to put the old ones back in at this point but I was a good guy and sent them off as cores as soon as the remans arrived. I ohmed the solenoids through the wiring harness and every one was 0.5 ohms. I'm not sure what to do at this point but I'm about to tear it back down tonight and pay close attention along the way to make sure it wasn't something I did. It sucks because I don't always work on diesel. I'm a gasoline mechanic and engine builder. I've built a couple lly engines and done upgrades but this one sucks.

In my experience duramaxes are the worst engines to diagnose they're a bitch compared to a Cummins or powerstroke especially with their limp mode problems if the slightest problem occurs. I'll probably never own one maybe if it had cast heads maybe but ehh..

I'd almost bet all the check ball seats in those injectors are wore out