Well I did some searching on here and I come up with a lot of ideas of what it could be. It is a 2002 6.0l mp112, with some small add-ons, I already replaced the main battery and that did not take care of the problem (good thing I got a discount ), I actually have two yellow top optima batteries in my truck and still the problem exists. I checked the connections and everything seems good. I will have to have someone else check it out as well to see if he can see something that I cannot. When I first had my truck the remote start worked about 1/2 of the time but not any more now. even when I start it with the key I have to give it some gas until the volts hit about 14-16 the volt gauge fluxes pretty bad when it starts it kinda mimics the rpms meaning when I give it some gas and the rmps go up the volts go up then when I let off the gas rpms go down and so does the volts until it shuts off or it wants to run. I also had a few times where I put it into reverse and the truck just flat out died on me ( volt gauge went slightly down). After I run the truck and park it for about 2 or 3 hours it will start up fine most of the time. sorry this is kind of confusing but I dont have a lot of time on my hands any more due to the economy being so fuked up so now I have to work my *** off! I was going to put some LT headers and do some other mods but I really dont want to spend money on something else until I get this figured out. I am going to try and have the fuel pressure checked when I get some time when ever that is, but other than that where else besides the fuel pump/check pressure should I be checking? spark plugs fuked up? injectors messed up? they are all brand new with about less than 30,000 miles on them. Does anybody on here want to check this out for me, I prefer someone who is close to Orange County area

 

First thing that I would do is to check the fuel pressure regulator. Pull off the vaccuum hose and see if fuel comes out. If it does, then replace the regulator.

 

My truck used to hesitate on start (dunno about rpm /voltage stuff) and it turned out it was bad gas and when I started going to shell the problem went away... tried everything but that before i figured it out.

 

+ 2 on the fuel reg...i had problem starting for a while...would do great when cold after running around and trying to restart had a hard time getting it going had a puff of smoke from excess gas..turned out that it was that pesky fuel reg....dont know about you volt meter issue

 

i only put premium octane gas in my truck and i only use shell/chevron/76, trying to have a guy check the pesky fuel reg. soon i just dont have time i wish i had ***!

 

mine was doing the same thing (except the volt/rpm thing)... i replaced the regulator and it was fixed. not too bad at all. the volt/rpm thing sounds like another issue, i would have you alternator checked out... if not that, then definately have your connections checked. idk what else to tell ya. good luck man

 

i would suggest checking the alternator as well. the easiest thing to do is to pull the belt off and see if you can turn the pulley by hand without much resistance. if you have a hard time turning it by hand then it needs to be replaced.

 

as of this time nothing has been done and it is getting worse now when i am driving it hesitates when i give it gas.

 

if it's hesitating when you press the accelerator, then i'd check the fuel pump.

 

OK had a guy check it out and thats pretty much what he is saying that i need to replace the fuel pump! So if i have to replace it then i want to upgrade the fuel pump!! So guys i have searched on here and see that many people go with dual walbro 255 or some are even running a single with a set up like mine. I hope to later turn it into a 408 with a tvs2300. with that in mind does any one else have any suggestions?