LB7: SAC 45 overs, who is running them?
- Thread starter THEFERMANATOR
- Start date
Where at? At idle I have found they flow slightly less fuel than a stock vco, but that quickly changes as pressure goes beyond 40mpa. I only have the basic flow sheet on a set which says at 160mpa and a 1700 pw, they should flow in the 165-168 mm3 of fuel(I want to say stock lb7's were in the 120 range at the same pressure and pulse).
I have been double dosing my Suburban with Opti-Lube XPD and the smoking is pretty much gone but the smell is still there. Someone please correct me if I'm wrong blue smoke at idle is leaking tip and hard or no start when warm is the injector returning to much fuel pass the ball and seat. I have never had a hard start problem just the blue smoke. My Bosch reman injectors were installed at 168,000 and I now have 232,000. Way to soon to put out another $3000 plus on parts. These injectors were installed in October of 2015. My better judgement says to put new injectors in with the SAC nozzles but I think I'm going to just do nozzles as I am curious . I know it would be a lot of extra work if I have to pull them back out. Might do a return test while I'm in there to make sure.
Yes, bad nozzles can cause blue smoke from a diesel. High return rates can cause a hard or no start as well as a hung injector staying open. I started to roll the dice on nozzles as mine had 71K miles on them, but in the end I opted for complete units as I know 99% of the shops out there don't have the equipment to balance them, and I wanted to make sure they were as close as possible. And at $1K for a set of SAC nozzles, they would have been an EXPENSIVE gamble.
Mine has a horrid eye watering diesel smell and it's been hazing bad at idle, like you can see it plain as day, so I'm guessing I'm gonna be due for injectors soon?? Truck has 95k on it.
I went ahead and ordered tips. I'm going to try it and see how much it helps. Hope to put them in this weekend if I get time. It's smoking to bad and looks like its going to be another month before I get time to swap the LBZ in.
I will say I've been working quite a bit on tuning, and have learned ALOT. These sac injectors require pilot changes imo. I tried adjusting the pulse and timing tables all over the place, but until I started making some pilot changes, I never could get my throttle feel/control where I wanted it at slow speeds. I'm still testing changes to them as I have found I can get it to run good hot, but once it cools off, it's a different animal. So now I have to wait for it to cool off netween changes so I can balance the changes to get good throttle control/manners hot AND cold while keeping it running smoothly. It's taking me some time though.
Well I got my tips installed over the weekend and what a difference. My balance rates are like Fermanators although they are starting to even out and my CFR went to 10 mm3. It runs a whole lot better, smokes pretty good on launch but drops quickly to a light haze and spools super fast but like Fermanator my boost has dropped off on the top end. I installed the new tune before I drove it so I can't comment on how they act on a stock tune. Originally my CFR bounced between 2 and 3 and smoked horribly and now it's at 10 occasionally dropping to 9. Best of all the blue smoke is completely gone:thumb:
Where did you get the nozzles? My truck just started hazing at idle. Still starts and runs perfectly with no fuel in the oil. Less than 30k on the injectors (i think) and I'm willing to take the gamble as i can swap injector nozzles in a evening with a buddy or 2 helping so I would rather do that than spend $2500 on injectors!
I wanted to post an update on this. As I had posted early on in the thread, I was not happy with my balance rates. Since then I've scanned a few other trucks(a couple with new injectors), and all of them had pretty bad balance rates both on just my V2, and scanning pass through via the scan tool. I've updated my efilive software a few times with no changes in readings. For the heck of it I recently picked up one of the sicotool's tech 2's. While I was waiting to pick my oldest up from school today, I was playing around with the tech 2 on the burb. I pulled up the balance rates on the tech 2, and they are just about PERFECT! I have 3 at 0, my worst is #1 at -.6 followed by #8 at .5, and the other 3 bouncing between +/- .1 to .2. So it looks like my balance rate concern never was a concern, but the efilive not reading my balance rates correctly.
It's always been troublesome getting it to read balance rates for mine(it likes to show -512), but the last truck I scanned a month ago had brand new injectors, ran fairly smooth, no smoke, and had 1 injector at a +13, and 2 others at +7. Just wanted to update this after what I found today. I've always questioned my balance rate readings on the V2 because of how smooth it ran off idle or rolling when balance rates zero out, but now I've confirmed it was giving me bad data. Looks like it's more than just LLY's that have trouble with the efilive scan tool.
It's always been troublesome getting it to read balance rates for mine(it likes to show -512), but the last truck I scanned a month ago had brand new injectors, ran fairly smooth, no smoke, and had 1 injector at a +13, and 2 others at +7. Just wanted to update this after what I found today. I've always questioned my balance rate readings on the V2 because of how smooth it ran off idle or rolling when balance rates zero out, but now I've confirmed it was giving me bad data. Looks like it's more than just LLY's that have trouble with the efilive scan tool.
That's interesting, because my FlashScan V2 and my knock-off Tech2 read balance rates identically on my two LB7s.
Have you tried formatting and reloading the FlashScan? Maybe some files are corrupt?
Have you tried formatting and reloading the FlashScan? Maybe some files are corrupt?
I've updated it and reformatted it several times with no changes. What threw me was the truck I scanned last month looked fine on his snap on scanner, hooked up my V2 and they were all 0's. Switched to the v7 scan tool and they were still 0's. Found an issue with high rail pressure and had to do a retune for a bad regulator to make it work, and the balance rates were all over the place. I've always had problems with mine not reading balance rates.
I know it's been 5 years or so, but if you have the time, I'd love to see how you left this tune. Currently feeling my way through this exact same jungle at the moment.
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