94 Explorer Slow Acceleration

[dhinch279]

I just bought a 1994 Explorer XLT with 63,000 original miles. It has the 4.0 with auto trans and 3.27 limited slip rear. It idles and drives great with no misses or hiccups at all. My only issue with it is that it doesn't seem to have much power and I put my first tank of gas through it and drove mostly highway and it averaged 16mpg. I have owned two 4.0 rangers previously and they had way more power than the Explorer. I could burn out pretty easily in the Rangers and the Explorer can barely chirp the tires. The spark plug wires are brand new, but I haven't pulled the Spark plugs yet. Any of you guys dealt with a problem like this before, It runs fantastic and never even sputters, it just seems slow, even my wife thinks so when she drives it.

Also, the previous owner installed a new water pump and radiator before I bought it, and now the temp guage fluctuates while driving it. It never gets in the red, but it floats back and forth slowly from Cool to Hot.

 

[hopster]

do a compression test

 

[gribly]

Could have air in the cooling system, and check the throttle cable - it might not be opening the throttle body all the way.

 

[shane96ranger]

I just bought a 1994 Explorer XLT with 63,000 original miles. It has the 4.0 with auto trans and 3.27 limited slip rear. It idles and drives great with no misses or hiccups at all. My only issue with it is that it doesn't seem to have much power and I put my first tank of gas through it and drove mostly highway and it averaged 16mpg. I have owned two 4.0 rangers previously and they had way more power than the Explorer. I could burn out pretty easily in the Rangers and the Explorer can barely chirp the tires. The spark plug wires are brand new, but I haven't pulled the Spark plugs yet. Any of you guys dealt with a problem like this before, It runs fantastic and never even sputters, it just seems slow, even my wife thinks so when she drives it.

Also, the previous owner installed a new water pump and radiator before I bought it, and now the temp guage fluctuates while driving it. It never gets in the red, but it floats back and forth slowly from Cool to Hot.

My Explorer was a 5 speed and it took more effort to burn out than I felt it should have. It could be the fact the Explorer weighs more. My Ranger (automatic) is far more likely to chirp the tires than my Explorer ever was, and it's quicker.

Weight of 91-94 Explorer is 4000-4100lbs.
http://www.vmrintl.com/reviews/Ford_explorer_91-94.htm

This has the extended cab at 3300 lbs.
http://consumerguideauto.howstuffworks.com/1993-to-1997-ford-ranger-6.htm

As far as the gauge fluctuating, I'd bet it needs burped. Hopefully the PO installed the thermostat properly, with the pellet on top.

 

[welderdude74]

its all about weight, Explorer weigh a good 6-800 more than a ranger

 

[gribly]

My 5-speed Navajo will do a brakestand in 2nd with 3.55 gears on 235/75/15's, there isn't anything really done to the motor.

 

[BeefStew42791]

ok, you DEFINITELY have air in the system with it fluctuating like that, assuming the p.o. replaced the thermostat as well with the repair like he should have and its not sticking. To get that out drive up on ramps or something similar to get the front end higher up, turn the heat on full blast and gradually hold your engine (in neutral of course) to a higher and higher rpm, filling the radiator as you go along. Then put the cap back on and drive with the heat on for a lil while as you keep a watchful eye on your coolant levels in the coming weeks.

As for your power situation I would suspect that since the p.o. didn't know well enough to do that step before he called it "done" I would also suspect that he wasn't as..meticulous with his maintenance as he should have been. Check the plugs, wires, air filter, maf, replace the fuel filter, etc. In other words, restore as much power as you can that age took away. Then after ALL of that, assuming the 3.27 gears are definitely correct, either change your driveline gearing or live with a very tall gear.
Oh btw, typically automatics require more power to burn out then manuals thanks to the torque converter setups.

 

[dasfinc]

Here are some numbers to think about regarding how fast an Explorer is compared to a ranger

Stock 5.0 Ford Explorer: 1/4th mile
18.2
Std cab, stepside bed ranger with bone stock 5.0 Explorer drivetrain (Including auto trans)
14.8, and I could have gone faster if I had a taller tire...

Weight and drivetrain loss make HUGE differences, I had a 5 speed 4.0 OHV 2wd Explorer sport that felt faster than my Super cab Auto 4.0 OHV 4X4 ranger

 

[4.0B2]

put 3.73's in it.. our 93 2wd, 4.0, a4ld, 3.73, stock tire size.. gets 18-20 in town and 22-24 on the road..

and the 3.73 will give you some power at the starting line to! lol.
i HATE 3.27's.. they are worthless!

 

[dhinch279]

You all make pretty good points. I get that the Ex will be slower than a ranger because of weight, but it seems really really slow compared to a Ranger. And the gas mileage is much worse than either of my old rangers and I had one with 33's. I do have a complete set of 3.73 gears already for the 8.8 and D35 that I kept out of my 36k original mile Splash Ranger when I put 4.56 gears in it. First things first I will do a thorough Tune Up and maybe even run some Seafoam through it in case the 63k miles are grandpa city miles and everything is Carbon Caked to crap

I was also wondering if it could be the O2 sensors and clogged cats or something. Either way, it looks like I am on the great adventure of Trial and Error

 

[4.0B2]

it could be cats clogged.. maybe?
just remember removing or gutting them is FEDERAL... and is illegal, but i won't tell! lol

 

[dhinch279]

Oh yeah, I forgot to add that I did the Burp thing. It made it alot better, but it still does it so I will probably have to do it again. Will air in the coolant system hurt anything? I can't see how it would unless it causes the engine to overheat

 

[Earl43P]

A quick trip to an exhaust shop will rule out an exhaust problem.
Call a few and see if they do a radiant thermometer test.
Some will throw that quick check at you for nothing if they aren't busy.

O2 sensors could be an issue, here's an interesting article covering both those subjects:
http://www.asashop.org/autoinc/july97/techtotech.htm

I'd check the IAT and ECT http://fordfuelinjection.com/?p=28 and http://fordfuelinjection.com/?p=29 since that's free if you have a meter, clean up the IAC and TB, throw plugs (inspecting each's condition) and wires http://www.custompistols.com/cars/articles/sparkplug.htm at it for if need be.

What size tire you running? I'd go much smaller diameter tires if it needs a set. That is a tall ratio. Might be most of the problem. 94 still uses the cable speedo so it's easy to correct, whether you re-gear (I envy that talent) or change tire size.
No sense buying new rubber if the tires are good and you've got a set of gears.

http://www.therangerstation.com/tech_library/Speedometer_Change_From_Tires.html
http://www.therangerstation.com/tech_library/Speedogear.html

Good luck with it. I'd do all the free and cheap stuff first.
Don't fix what ain't broke.

A thermostat is <$10, sounds like you may need one. Or test it, http://www.2carpros.com/articles/how-to-test-an-engine-cooling-system-thermostat

I don't know what got into me, I'm a linking fool this afternoon.

 

[shane96ranger]

Will air in the coolant system hurt anything?

Yes, and this is why

it causes the engine to overheat

 

[85_Ranger4x4]

Nature of the beast IMO. My parents bought a '94 with 3.27's in '96 with 55k. It might get 17mpg on a good day and is anything but overpowered. It has worn the factory sized 235/75-15s for as long as they have had it.

It always has been that way and as near as I can tell with 180k on it now always will be.

IMO the 4.0 never really has had a great surplus of power, and throwing a lot more weight on it didn't help. The obsene gearing was just a kick in the knees on top of that.

Now they have a '02 with the 4.0 SOHC and 3.73's. It is punchy out of the hole... but doesn't really accomplish a whole lot after that.