Had a 1994 Ford Ranger xlt 3.0 engine, which was getting 21.7-24.5mpg until it over heated and needed to swap replace the engine with a Taurus 3.0 engine (told it was the very same engine and would perform the same).

Now since the swap I am getting 15-16mpg no matter what.

Am I missing something, should I be checking on sensors/something or is this just the way things will be from now on?

Ideas needed

 

reminds me of when I bought my truck. they swore it got 21-24 mpg. I never ran a tank of gas out of it before it spun a rod bearing. swapped in a newer 3.0, and now I'm getting like 11-14. I never worried about it though, lol.

 

no swearing here; the older engine did get 21-24mpg...just needing some ideas on getting the mpg back.

 

Hi , the car makes h.p. 4-5000 rpm . the truck makes h.p. at 1500- 3000 rpm . Put the truck cam back in the truck . It's in the cam ! The truck has a roof top cam for low end power an torque . the car is made to cover the road quick with a longer duration an a short cam . my thoughts Bud

 

The Taurus gets crap mileage

 

x2, my buddy had a tore-a$$ and it got about 18mpg on a good highway trip.

 

thats about right

 

My kids 95 Tauras gets 36 mpg Canadian and has lots of power. I'm not sure what to say but the cam being wrong makes sense.

 

How long ago was it getting the good mileage? Was it back before it got cold out? Reason I ask is because in the winter the northern states get a different formula of gas that has more ethonal which cuts our MPG down. My f150 is about 4-5mpg worse right now compaired to back in the fall before it got cold.

 

No, it always got 21+ mpg in the Mississippi area...but the cam has me thinking now.

 

tell me more about the cam being a issue

 

I'm not buying the idea that the cam makes such a drastic difference in FE or even that the Taurus cam is that much different from a Ranger cam. I'd definitely look elsewhere.

 

Hi , Isky has been making these cams for years ! they're called tow cams ! It looks like a 45 deg. roof . they are made for towing and are very fuel efficent . the car cams look like a egg . Pull the old truck motor cam an look at it . Todays motors are better made for a car or truck . Hey , You don't have to believe me ! Type in Isky Cams on your search engine ! Then tow cam . My Thoughts Bud

 

Sure it makes a difference. You can completely alter the torque and hp curves by changing the cam and nothing else. Cars are set up differently and usually have the hp/torque higher up in the RPM band.

I have an older Celica which shares the motor with the trucks of the era, and the cams are completely different. The car's cam has the torque higher up and as a result the engine revs better, the truck has a lot of low end grunt and nothing in the upper end of the tach. It seriously feels like a different engine. It can affect mileage too...

 

did you copy an ad you read somewhere?

 

I'd listen to this guy ^^

 

Using the OP's numbers, we're talking about a 30~35% drop in fuel economy after the swap. You can't seriously be attributing that difference to a change from a production truck cam to a production car cam.

 

Did you drop a complete Taurus motor in? I know nothing about those motors but it might be possible the two different applications of that motor may use different size injectors.
Ford dropped the 5.0 in mustangs and Lincolns with 19lb injectors and T-birds along with other cars only got 14lb injectors.

 

just the block and then everything else was added to the block from the old engine.

 

I have someone looking into the cam now.

 

I don't see why. If it's a stock Ford cam, there's no way that it is the cause of a 30%+ drop in FE.

 

My moms 97 Taurus 3.0 gets 25mpg hwy 18 cty

My 93 Ranger 3.0 got 21 hwy 19 cty

 

That makes sense. A Taurus has a lower coefficient of drag than a boxy pickup, so its hwy numbers are better. In the city, the Cd is less important so the numbers are virtually the same.

 

Had a friend check the timing and it turned out it was not set correctly; after his resetting the timing I am getting 21mpg but the truck does not have the power to go up hills unless I down shift into 4th or 3rd and it gives a shutter...He said, its the spark plugs that the Company who put the motor in did not put in the correct spark plugs and it is due to the spark plug gap.

 

I don't see how the gap is going to effect the power of a non-boosted motor unless it is way out of spec on the wide side i.e. 0.070"+.
Gap is a direct correlation of cylinder pressure and coil voltage. Higher cylinder compression will snuff out a worn or over gapped plug if the coil voltage is marginal, don't know what the coil voltage of a 3.0 motor is but I am sure it is at least 40,000 volts so you should be able to run a gap of at least 0.045" or more before you would see any problem with the plugs.
I would be more concerned with wires bleeding off spark (arching) or too high of a resistance in the wires but that will usually effect idle more than top end.
I would check cam specs between the Taurus and Ranger cams and static cam timing.
Cam lift and duration can move your power and torque band all over the place.
Without getting into a bunch of engineering discussions on plug temps, cam and compression ratios I would check to see what plug temp range your running ohm out your wires and see what cam you got before I would start blaming something you don't even know what it is.