I have a 2001 durango 4.7 with 69k miles. I installed new platinum plugs at about 65k. Just last week the truck had a fast idle issue upon startup, cold or hot. Rev it once and the idle comes down. Started it 2 days ago and it has a cylinder misfire at all rpms. No codes. I pulled the plugs and all look good. I ohmed the injectors, all are 11-13 ohm's. Anyone have anymore ideas. I work on and build cars and can try just about anything...Thanks.

 

Follow up...With my wife in the truck and with it in gear, I had her powerbrake it and the misfire was accentuated. With the rpms up, I took a can of starting fluid and while spraying it into the TB the miss went away and it was smooth as silk. Looks like a fuel related problem. Tomorrow I am going to replace the fuel filter and maybe check the fuel pressure...

 

Sparks, platinum plugs in the D are a big no no. I put them in and then couldn't get my truck to stay running until it was hot later on. You should go with Champions copper plugs which are OEM that is propably your problem. There are quite a few people on here that know a lot about the D and Dodge in general. Look around for posts by Kensai he's the one I got that tidbit off of his advice is very good.

 

Exactly, Plats are a no go on our Magnums. That is probably your entire problem.

On your 4.7l, go back in with OEMs or NGKs.

For 5.9l's reading this thread, Plats are a no go for you too. Go back in with OEM (great lifespan, pinging however) of move over the the AutoLite 3923s. No book will tell you to use 3923s, only other expert and knowledgabe Durango owners. Ask for then by name, not cross-referenced for your 5.9l

HTH

IndyDurango

 

Interesting...and thanks. However, yesterday I had my wife put the truck in gear and powerbrake it. While doing this and with it missing, I kept shooting some starting fluid in the TB and she ran smooth as silk until I stopped. Doesn't this make it look like a fuel related issue?? Today I was going to place a meter on the fuel rail and see what happens. I will check into the plug thing...

 

Pull hose crapy plugs out![sm=bangbang.gif]

I'm sure it will solve your problem. Only run Champion OEM plugs, or like me run Champion Truck Plugs. Some people talk about NGK but I've never run them.

 

Not the plugs. I just installed a set of Champion 439's, OEM replacements. Still got the miss at all RPM's. Stuck a fuel pressure gauge on the fuel rail and it's bouncing between 30 and 50psi really fast. Not sure what that means, maybe a regulator issue if there is one.. my pontiac has a gauge on it and it's steady at 45psi all the time...Any thoughts??? Still looks like it's fuel related. Just to restate, I did squirt starting fluid down the TB with it under load(powerbraking) and the miss went away completely until I stopped squirting...Any thoughts on the pressure reading??

 

WOW!!![&:]

Well you didn't go wrong with replacing those plugs.

Your fuel pump is bad. It should hold at around 50-55 psi. Better to replace the whole thing at once instead of tring to replace parts. Checker usually has them stock. At Auto Zone they sell them for $189 so just tell Checkers that and they will sell you it for the same price, minus 10%

 

Thanks for the info. I priced the pump today and it is $260 at Autozone...Just seems strange that the pump would cause a cylinder miss. Compression test came out great..just wanted to cover all the bases.

 

It could be because of your fluctating fuel pressure. At random cylinders, they can temporary be starved of fuel as the fuel pressure is not great enough to be pumped thru the injectors. Thus causing a symptom like misfire which is not a misfire, but no fire at all on that cylinder.

As everyone stated previously, don't go with Plantium plugs. At least not for the Durangos. I went with the Champion Truck series plugs designed for the SUV's. They worked great. Now after 50k miles, I switched to Champions top of the line truck plugs with the iridium tips. My truck runs smoother and seems to have better firm acceleration too. I think these iridium plugs may outlast my truck.