Injector stuck open LB7 (maybe)

[Richard L Cox IV]

I have a 2003 Chevy 3500 LT with LB7 motor. I've owned it for 5 years, bought with 105K miles on the clock, and lots of white smoke. I had new Bosch SAC00 injectors ordered, bought the kit with all the fuel lines etc, and had a local shop install them Ran flawless until yesterday at 135k miles. Short trip to Home Depot and pulling in the driveway heard popping knocking sound and puffs of black smoke. I posted a video on Facebook LB7 forum and a few guys chimed in "stuck open injector"
I am wondering if that is a characteristic of the SAC injectors and if there is a fix for it. Most of the people also mentioned that I need to check the balance rates.

I want to diagnose this correctly and will buy a scanner but don't know where to start.

*what scanner should I buy?
* how will i determine which injector is bad?
* how will I rule out other problems?

I live in Tampa Florida and would outsource repairs to someone who has a track record of excellence...so recommendations are appreciated.

Cheers,
Rich

 

[West]

I have a Launch X431V+ that can read the injectors but this tool is $1300. Maybe there are others that cost less and can do the same. I had not heard of SAC injectors failing?

 

[2004LB7]

rare for SAC injectors to fail but they aren't as old as the VCO injectors for the LB7. but they do have a long track record on the newer models and it does happen but still not common.

stuck open injector will likely result in lots of white smoke. leaking injectors will normally be a gray or white haze at idle. you will be able to smell the raw fuel too if is stuck open.

if you find a scanner that has bidirectional controls you can try cycling the fuel pressure to max and see if it will unstick. otherwise you are likely in for a replacement.

 

[rfletes79]

I’ve had 3 sacs get stuck on me. 2 LDS 45’s and 1 SAC00. The sac was contaminate in the line, while going back together after an engine rebuild debris was introduced into the feed line which made it to the injector. I use Injector’s Direct for all my fuel needs (now) and they were able to fix the issue the next day. New parts installed, everything cleaned and flowed. Truck was back in the road the same week. ID is an authorized S&S dealer and stock a ton of their parts.

LDS warrantied/fixed their’s as well just was more timely, costly and was a actual injector failure and hung open.

Anything is possible, we’ve had 2 other sets of sac00’s fail which S&S warrantied promptly. These were not hung open, just high balance rates with specific cylinder misfire faults and noisy injectors.

We’ve been installing sac45’s and sac00’s for the last 6 years with only the above noted issues.


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