lmm low fuel rail preassure
 

I am having a serious problem with this code. and i know im not the only one. I bought my truck new in 08, once it had 60000 miles on it, it stayed in the shop 4 months, trying to figure out the probblem. then when the weather cooled of it went away, now that its summer again its back on. i put a banks kit on it. didnt help, didnt hurt. then moved on to a quadzilla with a dpf delete kit and a 5 inch exhaust, no help, no hurt, then tried a fuel prasure race plug. no different. . all this after they replaced fuel pump, injectors, preassure relief valve, fuel lines, fuel filters about every time it goes to the shop. or i change the oil. im at my witts end. what should i do??:argh:

im not real fimiliar with them. what i was gonna say, seems like ya put a race plug in. heres a bump for you :tu: good luck figureing it out

theres posts on another ? on low fuel rail pressure they said to shim the fuel rail, im hoping it helps my lmm mine goes into limp mode pretty regular throw the low fuel rail pressure code, i have a racing evo 7 stage dpf delete

that would be nice, but the lmm cant be shimmed as far as i know, i do have a ppe fuel race valve in it. it helped but did not cure. you can shimm the LB7 LLY and what ever the other one is. but thanks and let me know if im wrong, my truck has in addition to the ppe valve, a quadzilla with the dpf delete, banks cold air intake and intercooler, stage one garret turbo, and a 5" exhaust. to cure this problem, gm has replaced injectors, pump, fuel lines, cleaned tank, preassure relief valve, and anything else you can think of. my next step is an aftermarket pump.

Do you have a lift pump?

No I do not have a lift pump. but a friend of mine with the same problem does and it did not fix his. we have put lift pumps with bigger injector pumps, race valves,changed fuel lines, cleaned tanks. you name it, weve done it. i have two friends who are getting there trucks bought back. we have come to the conclusion that it is the fuel, if we add a quart of tranny fluid, we dont have any trouble, nor do we have trouble in the winter. thats when the fuel companys put the winter additive in it. it has something to do with either the thickness of fuel or the lack of lubrication. so if you want to fix it, put a quart of tranny fluid in each tank. Im sure the other additives would work. like lucas or whatwver you prefure, tranny fluid is just cheaper.

Ya thats weird, does it do it on a stock tune too? I see you have tried different programmers too. I wonder if a CP3 mod would help? The only trouble I have had with mine is Fuel gel and the change filter light came on. Then if I dont have my lift pump turned on you can tell it just kinds bogs down on the big tunes, but it doesn't thro a code. Did they put a guage on it to see what pressure the code came on? Anyway keep us informed as to what happens...

Do you always fill up at the same gas station? Look at their cetane numbers..The minimum is 40 I believe, but the average should be 47...