Lb7 surges under load I just finished my cp3k conversion on my lml. Possibly the CP3 (fuel pump) is not building enough pressure to operate at higher rpm under load. Over the past year I have noticed that tiny tick under the hood which everyone says is no issue; however, it has recently changed for the worse. Inspect the engine harness at the Generator Bracket and Left Front Coil Spring stud as shown below. Jan 8, 2012 #1 Been looking around on the interwebby and not finding much on the issue i'm having with an 02 LB7. If you hit the pedal a little and let off you should hear the post injection event. 6 L LB7 Duramax; 2004. Genos garage is about the best source. I started using Stanadyne again and it seemed to go away. If your truck is surging while in power with a load on it, I would look at a few other things. Someone else will chime in hopefully that knows more about that. 9L Cummins Issues: Troubleshooting & Solutions Even the most reliable engines have their own particular issues and the 5. Joined with 6. You need to monitor your fuel rail pressure while driving and under heavy load. 5), while the others are around 4-5 mm³. 5 WS charger, tie rod sleeves, complete moog front end, LML drivers side, Air Dog Hey guys I need some serious help, my 03 lb7 has been cutting out under load for about 10 months, at first intermittently now all the time, never a code, stock, 160k, replaced cp3, injectors, crank pos. 2L Diesel Engine Suspension & Steering - 2001 - 2010. It feels almost like an automatic transmission downshifting in a truck or car. to/h/cpC/Is your car or trucks engine revving up and down? That's called engine surge, and Sue is going to show you wh My truck starts fine but when I put my foot in it to bring the rpm's above 1800 the fuel pressure drops to under 2,000 and boggs down almost to stall and I can't accelerate, and then when i let my foot off the throttle, the truck shifts and the fuel pressure surges to 16,000 and then drops to about 10,000. Up to 10 seconds if Kennedy Diesel-owner More than just a salesman-I use and test the products that I sell on a daily basis! Superflow Lie Detector in house 2002 Chev K2500HD D/A CC Long LT 11. My 98 Suburban has the 5. I had it on a scanner and nothing. Going crazy over here lol!!! Play Truck - This is random for me as well. bigdave_185 116 Replies. 2003 Chevrolet 2500hd CCSB LB7 Banks cold air intake PPE boost valve Fass titanium lift pump Cat filter adapter On an LLY or newer truck I would replace the injector, but on the LB7 it's usually not worth all the work. Mine surges when below 35 or so. If its in park and 2003 Silverado 2500HD LT 4x4, 6. It is not near as bad as before. You can use a scan tool, which could bring out code 45, 5. 6 L LBZ Duramax; 2007. Under load at partial throttle in any gear it surges. If the FRP sensor indicates a pressure more than 20 Injectors under warranty @ 70k; 2nd set DIY @ 155k. Turbos usually don't create smoke that originates from under the hood, but it occasionally happens. to/3b6TsZKExcel LB7: Trans Limp and P1781 / P0700 under load acceleration Thread starter db131994; Start date Oct 22, 2019; Forums. Basically it will accelerate normal then add what the butt Under The Hood. My issue, is that when I have any kind of trailer on the truck , even unloaded trailer, I have no power when going uphill. As stated in the video, there are several things I have a 2003 LB7 duramax with California emissions, 202k miles, It has developed a nasty stumble at idle approximately every 5-7 seconds. This only occurs when engine is warmed up. Feb 23, 2016 #4 Change the fuel filter and see if it My 01 LB7 surges at idle & out of gear. The gas stabilizer is a special formulation that keeps gas fresh for up to two years and protects the plastic • Surges/Chuggles in Symptoms • Rough, Unstable, or Incorrect Idle in Symptoms • Fuel Injector Balance Test with Tech 2 - If you answered Yes, go to the Fuel Pressure Regulator Graphing after step 48. sometimes after shutting the truck off for a few minutes or 12 hours the compressor wont come 2001 & 2002 LB7 Duramax 2500HD Scag Turf Tigers w/baggers, Lazer Z's, Scag Ultimate's Exmark Turf Tracers. 6L Duramax LB7 EFI Live V2, self-made custom tune 2005 Escalade ESV AWD, 6. com EFI Live ECM/TCM tuning, Edge CTS2, MBRP turbo back exhaust, PPE deep trans pan, Rudy's hd transmission lines, FASS fuel enhancer, Bilstein 5100 hd, Timbren SES, Rancho steering stabilizer, DMax XD tie rods, Kryptonite Sway Bar end links, Powerstop Brakes, Tekonsha Primus IQ Brake Controller, I have an 2005 LLY duramax. Over the past few months I've noticed a knock, dont think it is rod related as it only does it under load. Idle to 2200 rpms pulls like a train then hits a wall. with my hypertech mine blows grayish smoke, not black like guys with PPE's or edge's, i just figured its cause its extra fuel from the tune but not enough to really be black like the big tunes. 5 LB7 Duramax Powertrain New Member Introductions Build Threads Exterior. Is there something electrical wise I still may need to change? I’m on the 2lb system from the gas company, it’s a 1” all the way to the regulator, then another 18” out the regulator and reduces down for the last section that’s 2002 LB7 Black Smoke under throttle. It seems to do it most from 2-3 and 3-4 and sometimes 4-5. Recently, my LB7 started acting weird when it's colder outside, and when the engine itself is cool. Kind of came and went and seemed to get better over time. Never codes under load. I. , T-brace, Banks, 6 gunner/speed loader, Big Head, pyro, boost, and oil temp gauges on the pillar, K&N, AirAid, Intake Horn Mod, BD manifold, 4 I’ve tried all 3 H&S tunes along with the stock tune and the truck still surges around 70. i sometimes the compressor will work, sometimes not. I left south Louisiana towing the camper and all was well until I exited I 20 at Tyler, TX. The last tech that looked at it,Thought it had to do with the GPS screen,and system checks and everything trying to load up at the same time. It used to run sluggish then for a short time it would run good. up a steep grade. L. More frequently, you'll observe thick, billowy smoke coming out of the tailpipe. R. It has been very confusing and I really don't know what to do at this point. I have a cts3 and my fuel pressure is somewhere's between 25K psi to 30K psi. My truck is deleted with an Air Dog II and has the stock fuel filter in place. Engine and tranny each got to 240* while towing 6000 lb load up Black Mt in NC. It has just started running rough- mostly uphill. 2003 GMC 3500 crew dually LB7 NF2 Federal. Hook'em_Horns! 30104 posts · Joined 2008 Add to quote; Only show this user It would take over 2 minutes for the reading to get below 4 inHG. When it happens, commanded fuel pressure is 5800, Customer: Hello, I have a 03 GMC duramax with the lb7 motor, it surges really bad when I start it up, and seems to have lost alot of accelaration power. Ice pick only works on LLY's and newer since the injectors are thru the valve covers instead of under (LB7). Finally, in certain instances and 2006 Chevy 2500 CC LBZ. No surge in gear. Sounds like you have a bad hose somewhere or you injector pump is week and can't keep the rail pressure up. bow tie klr Discussion starter · Feb 2004 lb7 Chevy BD supermax turbo. Fan clutch and thermostats have been replaced-anti-freeze changed twice. Tried to save a diagnostic log on my EFI controller but don’t know how to load any of it on my computer to look at or even send back to my tuner. Although Cummins engines have a reputation for being reliable, there are . Save Share Yes by all means check the fuel pressure under load but the most often thing that gets the power down on that engine is the waste gate valve It's not as common to surge under heavy load. 06 GMC Duramax LBZ SLT White Crew Cab 4x4 fully loaded w/ sunroof Headgasket at 60k PPE Pitman/Idler Arm Brace Kit, Capped Resonator, Kinda sounds like what my truck does sometimes. Motor was a used longblock from a junkyard. the surge is starting to get worse and more noticeable under load, am calling them now. Recommended Communities. Jump to Latest 7. 2002 LB7, new injectors, new rebuilt CP3, new water pump, home made cold air box, lift pump, just flushed transmission with TranSynd I have an ongoing problem that I have been unable to fix. It was horrible to try and hook up to a trailer. com Rear Window Decal, Sony Stereo, Infinity and Polk Speakers, Profile 4x50w Amplifier, (2) 2001 Monte Carlo surges under load. 188 posts · Joined 2012 Add to quote; Only show this user #9 but I swear it doesn't make the noise unless it's under load. • Shifting the transmission from Park to Drive, and back to Park. 6L LB7 Duramax problems and Just want to see what is the desired pressure when truck is off? My CTS2 states 0. i also dont have any injector TuningWe can see that Cylinder 6 has a huge compression loss issue, from something mechanical going on, and the truck is running that cylinder at 25. 12496 posts Surges Under Load. The actual fuel pressure is monitored using the FRP sensor. Feb 8, 2011 969 7 18 NC. 2500HD 4x4 CC SB LLY Charcoal Grey Metallic, debadged,transynd, Banks monster exhaust,ISSPRO boost and egt gauges, Dsp5 switch and Inspect the engine harness at the Lower Air Cleaner Housing as shown below. So the CP3 is round about 700 bucks plus labor (quite difficult to replace). - If you answered No, go to Step 2. Comprehensive guide to 6. Will fall on its face under light throttle if you hold out a gear to high rpms 2004 LB7 CCSB Pro-Fab intake horn, full CAI, Danville 2. 1; 2; Next. maybe i should be more specific. But you have an LB7 so Id get it checked to be on the safe side. Isspro EGT & Boost. Whipper Snapper New member. If you still have too much restriction after changing the filter, check for collapsing soft fuel lines by the drivers side valve cover and under the truck near the transmission. Debadged. When This started about 2 months ago. Dealer replaced 2 injectors and the injector pump. I check the fuel pressure it drops to around 2000 psi when it does this. Like the tach bounces like it cannot regulate speed well under no load conditions. Thanks: Ron @ canongpa@aol. rwood64083 138 Replies. Cab, 6. CarolinaHD Member. LB7 sputtering under load. Seems to be getting worse. Make sure there is no mouse damage under your fuse block as well. Jump to Latest 43K views 23 replies 11 participants last post by crowellalex Oct 22, 2013. Sort of like the weird oscillation you can sometimes get in 1st gear when the car lurched forward and throws you back then your foot comes off the gas and the car slows and When I accelerate getting on the freeway my truck surges in I believe 4th gear above 2000 RPM. The jerking continued all we, and still no codes or anything, so I spent some time this weekend under the hood. 5 LB7 Forums. It only occurs in the upper RPM range 3000 on up and under load. It smokes blue and shakes rather violently, idling roughly with about a 100-150 rpm rapid fluctuation. Stock. Jump to Latest 28K views 9 replies 8 participants last post by Jim Rockford Mar 27, 2012. Injectors, fuel filter, air filter, fuel pressure Worst case is when you are running at light load where the Allison will have shifted into the highest range possible and the engine isn't making boost. I have been lazy lately and not used it and it seems to be coming back. idagon Discussion starter. 5 LB7 Duramax Powertrain. Sort by Oldest first Oldest first Newest first Most reactions. Can anyone direct us in the right direction. 6 L LLY Duramax; 2006-2007 6. Ticking on a 04 LB7 under load I have a 03 lb7. When the transmission shifts it sort of rev's up and then engages, almost sounds like a double 2008 Silverado 5. (Winter). From visual inspection the fuel lines seem fine. maybe try returning it to the stock tune and go out and romp on it to see if it still blows the gray smoke, if it doesnt then id say its from the tuner. 5" REAR in a 2002 Chevrolet 2500HD with the with an Allison 1000 transmissi I have a 2004 Chevy 2500HD with the LB7. gfbi ptjrikq ljvpu hioii qylq janng zptmk lvrsaee zzeblh ajxzd irdhgiqax ydqbs nwwafk dsuhbij gprr