I am in a serious need of help! I have a 98 Dodge Ram 5.2L with 91,000 miles. It is almost like I have a ghost in my engine. There are some days when it runs like new and others when it sputters and loses power. Seems that on days when moisture is involved is when this sputtering is more present. For example at an idle it searches for a rpm, (average 700 Rpm) when the ghost is present is sputters and runs at about 450-500 rpm. I tested the fuel pump and it has more than enought pressure, and as you all know I cannot change the fuel filter unless I drop the tank. On one occasion it backfired through the air cleaner several times and barely ran. Similar to running out of gas. When I start the truck in the morning it has a sound of a vacuum leak (wierd) however all the lines are good I have checked them again and again. I have read other forums and have found many people who have had this problem, but not many have found a resolution. I have had the codes checked an none are tripped. One other thing I have noticed is on rare occasions I will come to a red light and the truck will rev a little and fluctuate RPM's. Please help!
Just a theory....Could it be the coil?

Remove and clean the IAC on back of the throttle body and the bore it fits into on the TB.

could be the iac or could be the intake manifold gasket pan plate...

could be a vacuum leak. I would spray wd40 around the intake where the hoses are or on the hoses while running. it it surges you found the vacuum leak.

clean IAC that will do the surge too

I cleaned the IAC and checked all the vacuum lines, and still the engine is running terrible. There are times when it runs great and others when it looses power and RPMs. An ideas would be helpful. Could the IAC be bad and if so would the check engine light be on. I have been told that the coil could be bad along with just needing a basic tune up. The spark plugs and wires only have about 10000 miles on them so I was gonna check other things first. It will idle perfect for a while and after about 10 minutes it will start to idle rough. Also if I tap the accelerator it will rev high almost to 1200 RPMs and then it will idle fine for about 10 minutes. Sometimes when I come to a stop light it will start to stall under 500 RPMs and then Rev. I am confused please help!

Backfire out the intake??????????? That sounds familiar. Rough idle sounds familiar too. I was reading up on timing chains that are stretched or going bad. They say they will cause backfire out the intake and a rough idle. Check google.com for backfire out intake and rough idle. you will see the timing chain come up many times as the problem. When they get too much slack the timing is off and does not work like it should when you have a nice tight chain

I had very similar symptoms and found a suggestion on this forum to started using mid grade fuel 89 octane or higher. all problems went away the first tank. So I would wait till you are down to approx. 1/8 of a tank then fill up with 89 octane or higher.

Ok so the sputter is back and worse than ever. I am using a better grade of fuel, the fuel pressure is strong, the air filter is new, the IAC motor has been cleaned, and the vacuum lines are good. The check engine light was tripped for the first time and the O2 sensor was what came back when the codes were checked. I think the O2 sensor was tripped because of how bad the engine is running. It went off the next time I started it. Aside from the O2 sensor possibly being bad what could set off the O2 sensor code.

have you done a compression test of all cylinders?

Distributor cap?
How long since the last tune-up?

Distributor cap?
How long since the last tune-up?


Not real sure how long it has been since the last full tune up. I purchased my truck about a year ago and the man who I purchased it from told me that he tuned it up right before I bought it. Would a bad Distributor cap make it idle mad all the time or just some? Thanks for your help!

A bad distributor cap and or spark plug wires makes one run pretty poor and the higher the humidity, the worse it'll run. All those misfires gets the O2 sensors acting kooky too.