jabber

Are the early '98 12V's affected by the bad fuel return line? I am trying to diagnose "why" my truck is so cold blooded even in moderate temperatures even after sitting in the garage overnight.

Symptoms:

Fires right up, but does not want to idle without throttle being applied for about the first 15-20 seconds, then wants to kill unless allowed to warm up for at least a minute or two.

When starting, throttle must be applied about a 1/4 pedal

Truck runs great and starts right up when warm. Just a small nuisance I am trying to get to the bottom of. I have turned up the idle and adjusted AFC star wheel, towards the engine all the way, could this be the problem

kelownadiesel

its a 12v !

jabber

yes its a 98

cwbronc

I just fixed mine. It was doing the same thing. While trying to diagnose it I heard air being sucked when I was pumping the primer. A mechanic traced it to the sensor in the screen/fuel warmer. the seal went bad and the part was back ordered so the mechanic by-passed it with fuel hose. It runs great now and has NO trouble in the morning. I was told that it won't get cold enough to need it, so I'm going to leave it 'till I have some spare $. I'd try by-passing the fuel screen and see if it gives you the same trouble. Good luck. Oh and ask any cummins mechanic and they will tell you the 12v's are better than all but the new engines. Or so I hear!

Mainemike100

12V are much better, cheaper to crank up and easier to fix without much in the way of specialized equipment. My .02

jabber

thanks for the help cwbronc. I have been screwing with this for a while. I am asuming that there was a loss in prime? here in maine its gets cold enough to where I need it to work. I will check it out. Thanks
mainemike100,Its nice to see another mainer here.

Sidewinder

I had a similar problem. I raised my idle and now no problem. I always like to start with the easy stuff. What RPM does your truck idle at?

TxDiesel007

that would be my first suggestion

Mine idles at 950 or so without the AC on (during the cooler weather here) no throttle at all to start, just a little bit after it bumps to keep it from shuddering a bit...

Rick

displacedtexan

Smae here, and it gets a little bit colder here than it does at Rick's place.

jabber

I have already bumped the idle up to 900, but when it first starts I'm lucky to have it running at 400-500 rpm. And if I don't give it any gas it will not start at all.

Willdsl

Jabber, mine is similar in that it needs alittle pedal to start but the if I don't keep alittle pedal on, it will drop the 500 rpm's or so but it doesn't die. But after its warm it will ride at 850 rpm's or so. Some have said this is normal. Some have said check the timing and bump it up to 16*.

jabber

It has been on my list to check the timing. Its just hard to spend the $200 for the right tools, but I guess it's time.
Thnak for all the help guys

neveragain

Cold this morning it is... -15*C. Yes stay with the 12 V for when one gets a 24V that doesn't produce much power the RE&RE guys are hopeless at diagnossing it's problems. For it rev's but doesn't advance the fueling much!!! The other day with the quad and the little 4x8 ' trailer it took 1500 RPM to do a shift up a slight grade!!