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Discussion Starter · #1 ·
Hello,

Just wanted to say hey to everyone and I'm glad I signed up, because I'm really stumped when it comes to my Dakota these days. Any and all help will be greatly appreciated. I have a 2004 quad cab, 4x4, auto with the 3.7, 100k miles. I first noticed after I'd had it awhile that when I would get up to 50 MPH it would start to miss. You could feel the engine through the sterring wheel and gas pedal bouncing, but once it got to 60 or above it went away and ran fine. I figured it was the plugs or TPS sensor so I changed both. It did not fix the problem. A week later I noticed that when it was idling the rpm would fluctuate up and down sometimes with a miss and then at other times it would be fine. It goes back and forth and hot or cold doesn't seem to matter although it does seem that when it's hot it is worse. The truck has NEVER shown a code. I then changed the air filter, PCV valve, MAP sensor and the inlet air sensor, also cleaned the IAC sensor and cleaned out the throttle body. Ran sea foam through the gas tank, had fuel pressure and cats checked, all good and STILL it has the same problems. I do not understand how a truck idling so bad and missing at 50, but not 60 cannot throw a code. I've read possible plenum gasket, but can't seem to see well enough down there to tell, but the engine is not making a single sound and oil loss is minumal for 100k miles. It has tons of power on the low end and untill I hit 50 it runs great until I come to a stop and then it idles horrible sometimes and other times not so bad. Have I said I'm stumped?!?! I'm a pretty good mechanic, but am at my wits end and so is my wife with my head under the hood all weekend trying to find out what's wrong with it. The dealers want 90 bucks an hour, but have said without a code it could take awhile for them to find issue and I'm not willing to spend alot of money on them for nothing. So has anyone got any ideas. I've thought from the beginning it was one problem, but maybe I'm looking at two problems and just don't know it. Thanks to everyone who reads this and maybe, just maybe someone may have the clue to fix this thing.
 

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Welcome!! Replace the little black vacuum plug on the driver side intake manifold. Could be dry rotted and sucking vacuum at certain rpm ranges or randomly. Also, replace plugs & wires. Random miss, high speed detonation, wet weather stalling. No problems since a fresh tune up. Good luck.

Thom
 

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Welcome to the Z Family from Southern Georgia!
Glad you decided to join us.
 

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Discussion Starter · #5 ·
Warm welcome / Vacuum plug

Thanks to everyone for the warm welcome, seems to fit my temp / blood pressure these days trying to solve the issues with my truck. Where exactly is the black plug on the drivers side intake manifold? I don't remember seeing one there. I have already replaced the plugs, but am wondering since I did it at the same time as I ran see foam through it maybe I should change them again???? Also, each plug has the coil pack on top not the standard plug wires. I posted my original thread on the Gen 2 forum. Sorry for putting it in the Newbie one.
 

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Welcome, glad to have you with us!

keep us posted
 

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Discussion Starter · #9 ·
Thom,

Thanks for the video, but I have the 3.7 and the engines are different. I do not have that vacuum plug on the top. I did however have it do something really wierd the other day. Stopped at a red light with foot on the brake and for no reason it felt like I had hit the gas pedal. The truck lurched forward for a second, scaring the hell out of me and then idled normally. Never ever had that happen and hasn't done it since. When it did it the RPM's jumped way up and then settled back down. Still idling like crap, no codes and still stumped?!?!
 
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