Bama_Dude

.I think after doing a search I may have a fuel issue.I noticed my truck hesitating on takeoff .It will stumble leaving from a dead stop.The engine gets loud and the rpm increases very slightly.It sarted a while back and only did it every now and then.Its doing it more often now.It runs fine at wot.I checked for codes but have none.I did change the fuel flter a week ago.It will do it sitting still in park and idleing also.You can hear it start raddeling for a second or two.Any thoughts?

Bama_Dude

Thanks for all your help,Im trading it in on a real truck,the duramax.

SafeHarbor

Hi, Bama_Dude,

Ever heard of "Bump" on a forum?

Bama_Dude

Yea ,but I thought I would try something a little catchier. still did,nt get any help.You think bump might work?

Bama_Dude

bump,bump,bump

Rauschbo

Sounds like you're getting intermittent fuel-starvation? Anything show on your gauges, and did you have the same issue before the Quad?

MikeyB

Try removing the Quad and see if the symptom is still there. Also could be the lift pump is going south or there's a problem with the CP3 pump.

MikeyB

GrandpasRam

Bama Dude, I had the same problem on my old '03 at 27k miles. No one else had reported anything similar at the time, so the dealer and Star had no clue. After replacing the lift pump, all six injectors, and not curing the problem (this was all under warranty), I noticed and told them that the fuel pressure would drop just before the stumble, and that told me that perhaps the fuel return valve on the CP3 was opening when it should not. They replaced the CP3 and the problem went away. This sounds just like the symptom you are having, and I suspect that the fuel return valve on your CP3 is defective.

Hope this helps.

SafeHarbor

See Bama_Dude? Three bumps, three answers. It works!

Spooler

Some days are better than others with getting replies. Most everyone works. WORK,WOR,WORK. That is all we do sometimes.....

Bama_Dude

Thanks alot guys I thought there for a while you were ignoring me. I Have the problem with or without my quad box.I guess I need to get it to the dealer.I just cant give up my truck for a week.I tried their free oil changes for a while but they keep it all day and I work out of mine.Thanks again.

dodgezilla04

mine would knock and shake at idle in a parking lot, then it progressed to doing it while driving. happened 3 times this weekend, then she wouldnt start. finally got it started and home, took 5 minutes to get it restarted, during the time it wouldnt start, i couldnt hear the LP running so I am replacing it with the BD kit. I will start on it tomorrow night. hopefully that is the problem, will keep posted.

GrandpasRam

My trucks have all been bone stock except for guages and the Scotty III air intake. Obviously, Star did not want to replace the CP3 without being sure, so they ran a tank of fuel with 2-cycle oil added to it to see if the return valve was sticking, and as long as there was a high enough concentration of oil in the fuel, no stumbles occurred. For their purposes it proved the CP3 was defective, and they replaced it. Hope this all helps when you take it to the dealer.

MikeyB

Hmmm. Maybe it's a good thing that I'm mixing TCW-3 in with Power Service Diesel Klean.

MikeyB

GrandpasRam

I always used a lubricity additive too, but the problem required a much higher concentration than should have been necessary. During the time the 2-cycle oil was running through, the truck was blowing large volumes of black smoke that prevented me from towing my 5th wheel 'cause I didn't want to soot it up, but the smoke problem turned out much later to be a boost leak (that is another story entirely).