Well i recently bought a 1999 dodge dakota ext cab, factory 318 but someone swapped the 318 and tranny out for a dakota r/t 360. I love it better than my 96 dakota, interior is awesome with black and gray. Anyways, since i bought the truck ive done the following, adjusted the tv cable so passing gear is right, new radiator, new thermostat, new pressure side power steering hose, new plugs and plug wires, new distributor cap and rotor button,cleaned the butterfly valves on the throttle body, un froze the back brake drums, new oil and filter.

Its got a decent amount of power but less than i was expecting. Compared to my dads ram 1500 with a 360, mine has hardly any bottom end. My dads throws you back in the seat. However mine at a 20-40 mph kick down will throw you back and his wont. So i figured thats how the motor was suppose to run.

How ever yesterday i took it for a 30 mile round trip doing 60-70 mph both ways. When i got home, on my back roads, i kicked it from a dead stop. When i did the truck threw me back harder than ever before and screamed, alot more than my dads truck does. I dont this about 4 different times, same result. I also done several kickdowns from 20-45 mph all of them kicked down harder than my truck ever had before.

So i figured i finally got it right. However today i drove it to town (6 miles) and back. Kicked it in the same spots as before and i got the results i always did before i took the trip. Curious i decieded to take the same trip again going the same speeds to the same places. When i got back home, on the same back roads at the same spots the truck acted just like it did after the first trip.

So in doing that i now know that something is wrong, what it is for sure i dont know which is hopefully where you guys come in. The truck stayed at the same tempurature (180 degrees) every time i tested it. There is a bad 02 sensor that i need to replace still. I put a bottle of fuel injector cleaner in today when i got home hoping that maybe on of the injectors has some trash that will get cleaned out.

But im at a loss as to why the truck performed better after both long trips compared to short but equally time consuming trips. If anyone has any ideas id love to hear them.

 

There are ALOT of factors that can come into play when it comes to performance of a truck. Road conditions, outside temperature, Quality of fuel in the gas tank, temp of tires, you name it. Since you have an o2 sensor out im assuming you have a check engine light on. The fact that its even on means your truck is running in "safe" mode. As a fail safe, whenever your MIL, (malfunction indicator light) is on, your pcm sets everything to run rich...more fuel... you lose your factory settings, your data tables, all data your truck has saved from its most efficient period of running. Its possible you pulled the battery before your first road trip, which would have reset the MIL and started you with factory settings instead of a safe mode, that is until your truck goes through a drive cycle, then the fail safe comes back into play. There really is no way to tell why your truck did better the long trip versus the short one.

 

I noticed a Durango out there that slapped an 6.1L into his and tossed the 318 or 360 or whatever it was. Seek out a 6.1L and swap.

 

My check engine light hasn't been on for the past week. I've got a friend who's got a code reader and he cleared the code. But either trip it wasn't throwing any codes. I took the trip on the same tine of day and the weathers been consistant for the past few days. So.... Oh and I've been running the same gas from the same store with the same octane (87). And I haven't disconnected the battery but once soon after I got it several weeks ago.

 

if your light isnt on, then your 02 sensor isnt bad...clearing the code wont keep it from turning back on. As far as the fuel quality, what day does your station fill up? what day did you fill up? anytime a station tops off its tanks the trash floats around for up to a day and a half...

 

They fill up on Thursday and I got mine Friday. There's a good possiblity that there was trash in the tank before I bought it. Hopefully if trash is the problem the injection cleaner will help it out.

 

good luck...

 

I don't see this being a problem. That's just me though.

 

well? what do you see then?