[Ram4477]

my friend has a 1998 2500 CTD auto. it idle's fine when it's warm but when it's cold it won't idle at all it, tries to run at 400 rpm and dies often. Any one have any idea's what it could be?

 

[Buzzbass]

Has the lift pump been changed yet ? What the fuel pressure like ?

 

[big gross dodge]

It seems Buzzbass thinks its a 24 v ,but I bet its a 12v.Correct me if Im wrong.My 12v does this when its cold too.You can bump up the idle on the pump easily.On a 24v you cant ,its controlled by the ecm.I simply hold the idle to 1000 for like 30 seconds then its fine

 

[Ram4477]

Should he adjust the idle? Exactly where is the adjustment? It idles fine when it's warm, but it won't be warm here in Alaska untill May or so.......His manual vaugely says something about idle adjustment but we can't find it.

 

[mjamgb]

I assume the block heater is being used and is functional? My extension cord was bunk and I didn't know it until I tried to use it for a drill... approaching spring (doh!)

If you really do have the 12V the adjustment is simple but not easy (!)
On the firewall side of the pump is a throttle stop bolt with a jamb nut. 10mm for both. Tight quarters. You can "just" see it through all the stuff on there.

The idle should be 900 rpm with the air conditioner on.

I had similar issues (and stalling when I "snapped" the throttle shut or running the steering to the stop) and did this... All better, however I need to turn it down a smidge since it is idling a little high now.

Also, folowing the operator's manual and holding the throttle at 1000 rpm until the oil pressure registers helps a lot. I also hold it for an additional (short) period of time at about 1200 rpm after the oil pressure comes up.

Another thing is the power steeing fluid. If the fluid is AT ALL burnt or "worn" looking/smelling have the unit flushed. The pump also runs the vaccum pump and gets a workout. If it starts to drag, the engine will labor.

These mechanical FI engines are like old carbureted gas engines in that loads on the engine will not be adjusted for by an engine management system like on newer FI cars. The upshot is that you need to "fiddle" the idle speed yourself.

 

[big wally]

cold staet idle problem

For a P7100 pump.
A manual throttle, will solve your problem. Start, set throttle to 800 or 900 for a few minutes,now you are warmed up.

 

[dirtrulz]

Had a problem like that wiht a work truck. Found problem to be something with the governer not reacting quickly until oil was warmed up. Made worse if we ran a heavy wieght oil in the winter. Only problem wiht cranking up your idle stop will be with a high idle when truck gets warmed up. It should only idle like that for a few seconds until oil starts circulating. One thing we did to mmake it better was to install one of those adhesive oild pan warmer pads on the bottom of the oil pan and plugged it in at night, then the oil would be warm at the pump would work much quicker.

 

[big wally]

Cold start idle problem

The problem with mine (96 2500 4X4), is that there is no, automaic high idle when cold. This model, has no high cold start up mode, totally mechcanical, P7100 pump, the manual throttle, was the only way to, warm her up.
(96 2500 4X4 automatic 375,000 kms)
My 92, automatic, had a high idle kick up.
With this throttle and it plugged in, at -35 degrees Celcius, 5/40 synthetic oil, NO PROBLEM!