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Discussion Starter #1
I have a 2001 Dodge Ram Van with 152,000 miles and for the past few years it has stumbled for 20 or 30 seconds after a cold start. After 20 or 30 seconds it runs fine with no problems the rest of the day. But lately I have noticed it lasting a little longer and it will stumble for a few seconds after leaving my driveway. Its been a year or two since I replaced the plugs, plug wires, distributor cap, rotary button and new fuel pump, so I don't think these things are the cause. It runs flawlessly other than the first min. or so when cold. It never dies but it does stumble like it is going to die. Does anyone have any suggestions or tips I can try?

Thanks for your help!!
 

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Sorry, I forgot to post the engine size. Its a 318 and it has no codes. It was doing this before I changed any of the parts. I also forgot to mention that I replaced the IAC valve a couple years ago. It has been doing this for about 3 years but never was to bad until recently. None of the parts I have changed helped the problem except for the idle valve. It didn't stop it completely but it made it better until not long ago.
 

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Is this condition aggravated in colder weather? The next time on a cold start, shut the engine back off after 20 seconds or so and pull a spark plug to look at the tip. Any black carbon fouling?
While the engine is cold, sometimes the correct OEM spark plug heat range is critical.
The correct Champion copper core OEM plug (RC12LC4) recommended replacement interval is 30K miles. Has the van exceeded this in the 2 years since replacement?
Copper offers the best burn. If you changed over to platinum, this may contribute to cold driveability issues, like sags, stumbles and sputters (misfire).
Platinum spark plugs used in an engine that doesn't call for them may last 100K miles, but may cause running problems.
 

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Discussion Starter #5
Cold weather does seem to affect it slightly more than warm weather. I will check for black carbon on my plugs and now that you mention it, I think I did use a platinum plug on the last change. It has been over 2 years since they have been replaced and they have roughly 30 to 40,000 miles on them. Do I need to check all the plugs or is 1 sufficient?

Thanks for your help!!
 

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If one is carbon fouled, it is likely that the rest are also.
Always use the spark plug brand and type called for in the owners manual or on the underhood label.
A lot of factory R&D goes into selecting the optimal spark plug specifically for your vehicle. The advantage of Platinum may be longevity.
Copper is a better conductor of heat and electricity than platinum or Iridium, but softer.
 

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DO NOT FEED THE TROLLS!
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With the '01 3500 I drive at work, I find that if I start it cold and attempt to drive immediately after putting it into Drive it hesitates, but if I put it into Drive and hold the brake, letting it sit for about ten seconds in drive like one would at a traffic light, it doesn't hesitate.

Being that it's work's van I don't really worry about it much, and until it actually lets me down they're unlikely to fix it even if I turned it in.
 

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Discussion Starter #8
If one is carbon fouled, it is likely that the rest are also.
Always use the spark plug brand and type called for in the owners manual or on the underhood label.
A lot of factory R&D goes into selecting the optimal spark plug specifically for your vehicle. The advantage of Platinum may be longevity.
Copper is a better conductor of heat and electricity than platinum or Iridium, but softer.
I will try new plugs in a day or so and let you know the outcome. It needs plugs anyways I assume. So while I have everything apart I will just go ahead and change them out.
With the '01 3500 I drive at work, I find that if I start it cold and attempt to drive immediately after putting it into Drive it hesitates, but if I put it into Drive and hold the brake, letting it sit for about ten seconds in drive like one would at a traffic light, it doesn't hesitate.

Being that it's work's van I don't really worry about it much, and until it actually lets me down they're unlikely to fix it even if I turned it in.
That's the exact same thing mine does. And like you I just ignored it because it ran fine and it's just a work van. But I would like to see if there's a fix for it. I will try the brake while in Drive and see if that helps.
 

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I suspect that with mine, the anti-drain-back seals in the transmission are not working fully, and letting the transmission warm up brings pressure up to where it needs to be.

I could be wrong though.
 

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Discussion Starter #10
ImperialCrown said:
If one is carbon fouled, it is likely that the rest are also.
Always use the spark plug brand and type called for in the owners manual or on the underhood label.
A lot of factory R&D goes into selecting the optimal spark plug specifically for your vehicle. The advantage of Platinum may be longevity.
Copper is a better conductor of heat and electricity than platinum or Iridium, but softer.
Ok, so sorry for the delayed response. Haven't had the time to inspect my plugs til today. So, I took out the old plugs and sure enough they were Bosch Platinum plugs. I bought the correct Champion copper plugs and will be installing them today. I will do a couple early morning starts and let you know the outcome in a couple days. Thanks for your help!!
 

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Discussion Starter #11
ImperialCrown said:
If one is carbon fouled, it is likely that the rest are also.
Always use the spark plug brand and type called for in the owners manual or on the underhood label.
A lot of factory R&D goes into selecting the optimal spark plug specifically for your vehicle. The advantage of Platinum may be longevity.
Copper is a better conductor of heat and electricity than platinum or Iridium, but softer.
Ok, so I changed the plugs yesterday and "WOW" what a difference. I went ahead and changed the wires also, although they looked pretty good, I just decided to change them while I had everything apart. I tried a cold start last night after changing them and again this morning. What a difference!! It runs so much smoother now.

I never realized a platinum plug would cause issues with the way it runs. I expected a higher quality plug would help instead of hurt it. But I am no master mechanic, just always been good at fixing things. Live and learn I guess...

I cant say how much I appreciate your expert advise!! You obviously know your Mopar's...
 

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I have had a bad experience with Bosch Platinum plugs in three vehicles. They tended to foul much earlier than they should have, much earlier than cheaper plugs did. I have heard that the heat range may be off on the Bosch plugs and that is the problem. I just know I won't try them again.
 
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