alright so i drive a 2001 dodge ram quad cab 1500 with a 318 nv3500 4wd. The truck has 187000 miles on it but it got a new autozone motor 20000ish miles ago truck sounds healthy idles smooth and starts right away but gas milage is somewhere around 10 to 12 mpgs and just doesnt have the power i feel like it should have. When taking off around 1500 rpms it will sort of lose power and surge back a little bit. i feel it may be a fuel problem but unsure. any ideas.

 

10 to 12 mpg is decent in these trucks. The ethanol in the gas don't help either. How long has it been having the issue? Start with simple stuff, tuneup, proper spark plug wire routing, condition of plenum gasket...

 

If your new engine only has about 2000 miles on it, its not even broke in yet. You need to give a new engine 6000 - 10.000 miles for the rings to seat and for everything loosen up a bit.

Your mileage will get better, just give it some time.

 

20000 should be broken in. Plenum done yet? Got rid of the death flash yet? 10-12mpg is usual for these trucks. Just remember you're driving a 6000ib truck with an under powered motor...

 

have a muffler shop do a back pressure test. I just got an 01 with 77,000 mi and it had 5psi backpressure. A new cat helped and a new Denso upstream 02 sensor helped even more. I wouldn't of thought the cat was not flowing with that mileage. If you'r is original it's probably clogged up and robbing power.
My last 3 trucks only weighed in at around 4500 lbs.? Don't lose any sleep over the death flash.

 

what is the death flash? reflashing the computer?

 

Death flash was chryslers answer to not having a knock sensor on these trucks. It retarded timing even more than what was typical, which reduced power output. Then there is 'torque management'... which further reduces power in the lower RPM range (where trucks need it most....) to help prolong the life of the weak transmissions they put in them.

Getting a tuner will get rid of the death flash. Some are better than others. Hemifever is pretty much regarded as 'the best' here. Not only does he retune the engine for better power, he also gets rid of torque management.

 

This seems as good a place as any to pose this question. So far, I have:
• Replaced my A/T fluid and filter
• Re-attached my front band anchor
• Adjusted my bands
• Replaced my pre-cat O2 sensor
• Replaced my distributor cap & rotor
• Replaced two destroyed spark plugs (#'s 2 and 8)
• Seafoamed the crap out of my engine, gas line and crankcase (Hit my Camry wagon too, while I was at it - my wife was fasinated by the amount of smoke that came out, as were a couple of my neighbors.

And ordered (and recieved) a Cloyes HD double-roller timiming set and a Hughes plenum repair kit (LOL).

My question is, why has my mileage gone from 9-10, to 7.23 mpg, from 14 mpg a couple of years ago? This is from my 1998 1500 Quad cab 4x4 5.2 L 46re...

Can I expect anything better once I do the plenum repair?

 

Yes. Should go right back to where you were before. Verify you cat isn't clogged, and the front O2 sensor hasn't been destroyed by burning oil though.

 

Something is wrong somewhere, or two, or three. After you get your plenum and timing chain in, check your mpg and go from there.

Check for codes stored, distributor timing, intake and exhaust flow, quality of spark, fuel flow at injectors....you will find it and get your mpg back...just need to do some investigative work.

I hope it's not the band anchor