stotts

hello all, i have a new to me 2004 2500 with a 6.0 and im having some problems. sometimes when i first start it it wants to stumble or fall on its face. it seems to stop after a few min. however today it was running very bad. felt like it wasnt getting fuel, would barely move the truck and stumbled a lot. had to pull over and ease into the throttle to build rpms then put in gear and give it heck to get it home. the engine light has been on for a few days, after work i went to advance auto seemed to drive fine, codes said mass air flow then said vaf and also running lean. PLEASE HELP AS I HAVE NO IDEA WHERE TO START. THANKS IN ADVANCE!

MDTAHOE

You need to check the fuel pressure.

stotts

ok did that, 55psi, also unhooked the MAF seems to run ok but not sure this is it

therewolf

Welcome to the Chevy Forums,stotts.

OK, my truck is that year, type, and engine size.

First thing, there is NO inline fuel filter. Go ahead, check and be sure.

Second, the 100,000 mile Iridium plugs? Replace them every 50K, trust me.

Third, hows that air filter doing? I don't specifically want to plug a CAI right now, but even a cheap new air filter from a discount store could be a world of help.

What is the mileage?

I've been generous to my truck with tuneups, and even with it's new 342 gears(you probably have 410s)it's a hard charger off the line. Do you have any trouble lights on the dash? Watch your shift indicator when you first turn on the ignition carefully. Any prompts?

jk11blueboi

what was the code exactly, if it was p0101. i had that problem and my car seemed to stumble alittle. use CRC maf cleaner to clean the maf. clean the throttle body. and check your plugs.

the maf code tends to usually make the lean code like p0171 and p0174 pop up. my case it was also the fuel filter bc i had an 03. with your 04, you don't have an inline filter. it is in the tank

also check for vacuum leaks with carb cleaner, spray it near the intake manifold and listen for idle change.

therewolf

I have to agree with blueboi, that does sound like a vacuum leak to me.

s34n

run sea foam thru the intake. take the hose from the back of your intake to the powerbooster. unplug it from the boost. idle will change, truck wont die, no codes will be thrown. no worries. its a vacuum line so its going to suck the fluid in quickly so go easy otherwise it can suck in too much too quick and will die making it hard to start. if it dies plug the hose into the boost start the truck and pump the pedal to allow fuel and air to enter the combustion chamber. dont be afraid if you see a plume of white. its just the sea foam burning off thru the cat but do that until the can is empty. i have a video on you tube.
http://www.youtube.com/watch?v=TRJ5k_A1uis

UH60sSuck

I do the same thing with the sea foam. I dont know if it makes a difference but after I run 3/4 of a can to a full can I shut the truck off and let it sit for 10-15 Minutes then I start it. Will blow a *** load of smoke like s34n said. Will Clean the crap out your engine. I do it to mine every few months. Another tip.When you do this you can cover half the end of the vacuum line with your thumb while you pour it in and if it tries to die you can usually keep it running by moving your thumb.

s34n

haha seeing the big *** plume is the best part of sea foaming. lol. i did it once slowly and just let the foam get sucked in and it just barely smoked

UH60sSuck

Yeah if you shut it off after it sucks it all in and let it sit for like 10-15 minutes and then start it and give it some gas you will smoke the whole neighborhood out lol. Should of saw it when I did my 1990 Ramcharger. Dont think it ever had it done to it before. And on top of that I had to drive it home right after and had my buddy follow me home and he had to fall back a few hundred yards because he couldnt see.