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Poor Gas mileage & Loss of Power "Solved"
#32
I got a spare one kicking around both are old but maybe il try it my idle sucks. It seems like the truck jumps around so this seems like a good idea for even me. It could be the o2's but it used to idle like a dream. I have all new cap rotor, wires, plugs ect... 10 k on them. Wonder if swamping the motor screwed with it? lol.
#34
#35
Thanks Fox. Please post back on the MPG. My MAP has like 1.2 volts on the output wire at idle. Which is way down at the low end of acceptable specs but I have not been able to change it yet. I have to downshift if I want to maintain speeds going uphill and my truck just seems weak and is using more gas than it used to.
Thanks for the update.
Jimmy
Thanks for the update.
Jimmy
#36
I checked for codes tonight, found none. I put on the MAP sensor that came with my V8 throttle body from the junk yard and it had 1.49 volts on the output wire at idle. This is higher up in the low end of acceptable specs, and it's closer to specs than my original MAP sensor. That gave me some hope that all I need is a new MAP sensor, and I went for a test drive and could instantly tell a difference. The truck pulled harder and was easier to hold speed going up hills, acceleration from a stop was noticeably quicker and it didn't make the air-sucking sound that had been present when I would floor it, like to pass someone. I had thought the noise was from cutting a bigger opening in the air box. The throttle response was a lot better.
I'm going to leave it as is and really test drive it on my commute to work tomorrow. But judging from how much better it is now, I will be buying a new sensor tomorrow after work. I have no idea how many miles are on this one, and if it did this much better at 1.48 volts, I think it should be even better still with a new sensor that puts out the 1.5 to 2 volt signal the MAP sensor is supposed to provide. I would think my MPG should get better too.
Jimmy
I'm going to leave it as is and really test drive it on my commute to work tomorrow. But judging from how much better it is now, I will be buying a new sensor tomorrow after work. I have no idea how many miles are on this one, and if it did this much better at 1.48 volts, I think it should be even better still with a new sensor that puts out the 1.5 to 2 volt signal the MAP sensor is supposed to provide. I would think my MPG should get better too.
Jimmy
#37
well after driving around today, doing about 70 miles, i killed off 1/4 tank and was pretty hard on the throttle. i mean the first 10 miles i had the throttle WOT for the most part while in overdrive. so, it's looking promising. despite i have a cat back magnaflow, K&N intake, superchips 93 tune, etc.. i think il be doing a lot better than 15 mpg. as a disclaimer, this isnt a miracle cure for **** poor fuel mileage. keeping your truck well maintained helps. do your regular tune ups, oil changes, and preventive maintenance and you'll be set for the long haul.
#38
I changed mine because I wasn't sure if ever had been and my truck does seem to run and respond better. Crazy that little sensor can make such a difference. My local Dodge dealer has them for $23, best $23 I ever spent. Like stated earlier it isn't a miracle worker, but I'ld say it's close
#40
My truck ran a whole lot better on the way to work this morning. I'm going to install a new MAP sensor and go ahead and do a tune up with new 3923's, wires, brass contacts cap and rotor and clean my TB and IAC tomorrow. I have no idea how old the junk yard sensor is, and a new one should do even better. Truck should do a lot better on power and I hope to bet getting better MPG too after I do the tune up.
Thanks for posting this. I had no idea the MAP could be causing my loss of power. I thought it was just my 3.9 showing its age, because I always keep it tuned up, maintenance done ahead of schedule and I really try to keep it in the best shape possible.
Jimmy
Thanks for posting this. I had no idea the MAP could be causing my loss of power. I thought it was just my 3.9 showing its age, because I always keep it tuned up, maintenance done ahead of schedule and I really try to keep it in the best shape possible.
Jimmy