i have a 1999 4wd explorer with like 70,000 miles and the accerlation is kinda sluggish. I really dont know what the acceleration on the explorer is supposed 2 be since i never drove a diff explorer and my explorer has been sluggish ever since i bought it (with 50,000 miles). Is this reg? and what would b the BEST upgrade to improve acceleration?? Preformance chip?? wut? thanx

 

which engine do you have? They offered three engines in 99:

the 4.0 Liter OHV V6, 4.0 Liter SOHC V6 and 5.0 Liter OHV V8. If you have the first engine I listed, they aren't real fast. They do get the job done, though and are reliable. That is what I have in my 98 Sport, my previous 92 EB and what my father has in his 00 XLT. Not many mods for it, as far as I'm aware.

 

4.2 ohv v6

 

There are lots of mods for the 4.0 OHV V6, its the bigger SOHC V6 that don't have any. You might need a plug change (Bosh platinums work nice) and to clean the MAF and IAC for right now though. A nice K/N drop in with a drilled air-box or a KKM air filter will help too.

 

"There are lots of mods for the 4.0 OHV V6, its the bigger SOHC V6 that don't have any. "

oops, my bad.

HpNoTiQ, btw, the 4.2 is only offered in the F-150. You musta ment 4.0 OHV.

Good luck

 

thanx for all the help, but can u guys gimmie a list or sumthing 1-5 or 1-10 of the top acceleration upgrades ("1" being the upgrade that most effects the accelertation of course) thanx that would help ALOT....

 

I had the OHV in my old '98, and the mods I did that seemed to make the most improvements, were.

1. Cleaned my MAF and IAC
2. K/N drop in air filter and then drill out my air box
3. new Boch platinum plugs and wires
4. new serpentine belt (old one was worn and alittle loose)
5. synthetic oil

1-3 where the biggest, I felt a difference right away after doing each of them (about a week to 2 weeks between each). 4-5 helped too. Keep in mind that Explorers are not that fast off the line, especially the 4x4s. They are not light vehicles. Cleaning your MAF and IAC are basicaly free. All you have to do is buy some o2 sensor and varnish safe carb cleaner. The K/N cost me $50 and lasts forever. Plugs and wires vary in price and you don't have to get the Bosh ones, I just have used them for years and trust them.

 

How do u go about actually cleaning the MAF and IAC (i think the MAF is the mass air thinger that is near the air filter but how do i clean it?) and i have no idea wit he IAC is..... thanx (how do i clean the IAC also

 

How do u go about actually cleaning the MAF and IAC (i think the MAF is the mass air thinger that is near the air filter but how do i clean it?) and i have no idea wit he IAC is..... thanx (how do i clean the IAC also

 

I can't remember exactly where the IAC is located on the OHV, if I remember corectly, it is on the top back of the engine and has a black cap on it. All you have to do is remove it and spray it down with varnish safe carb cleaner...

 

wow thanx, cleaning the MAF really helped, no longer does my X stumble on itself when i put the petal to the metal, lol. Now i jus need 2 find where this IAC is, thanx

 

Great! One thing I forgot ot tell you, but you may have done it anyways, but disconnect your battery when doing any of these upgrades/mods. The computer will "relearn" when you take it for a test drive after the changes.

 

This looks like it has a lot of reward for a little effort...

MAF:
-Go to Pep boys or wherever and buy yourself some security style T bits. These are the star bits that have a hole in teh center. If you look at the screws on your MAF sensor you will know what I am talking about, and they are great to have around when your buddy needs to clean his MAS.
-disconnect the - battery cable
-ONce you have the right bit in hand, unplug the wire harness from the mas sensor (screwdriver or packet knife, be careful, dont break it)
-Pull the plastic sensor from the aluminum MAS housing out straight up. Careful!!! dont bend or touch the elements on the ned of the sensor!!!!
-If you look at the sensor itself you will see two little wires running across, similar to the filiment in a light bulb, you may notice some light brown buildup on the little "hot wores" you may not, either way it;s probably dirty.
-Hold the sensor out and spray the carb cleaner on it, the goal here is to remove any buildup on the hot wire elements, so you dont need to soak the entire thing, just spray the little wires themselves.
-Let them dry!!
-re-install the o ring, and re-insert the sensor into the MAS housing, careful! you dont wont to bend the hot wires, they are fragile and MAS's are expensive to replace.
-re-install the security screws and wiring harness.
-go drink a beer
-hook the - battery cable back up and you are done.

Now I am aware that this proceedure does not work on all years, some of the later model trucks (darkfox this is you) have a big *** plastic housing around the MAS sensor and you cant exaclty remove the sensor from the MAS body, deal with it. Spray the carb cleaner in there as best you can, let it dry, re-install. The important part is to disconnect the battery so the computer can re-learn the new signals the clean MAS is sending.

Idle Air Control Valve:
-disconnect the - battery cable (same reason as above)
-Unplug the wiring harness from the IAC (again careful, pocket knife or screwdriver, dont break anything!!!)
-Unscrew the two 10mm bolts that hold the IAC assembly to the upper intake manifold. Be careful not to damage the gasket!!!
Take the IAC to your work bench, kitchen table, backyard, whereever you want to do the work.
-Remove the two phillips screws that hold the electronic sensor to the IAC body, set the electronic solenoid aside (it doesnt get dirty)
-Look at the IAC closely, a flashlight is good for seeing in there. Open and close it a few times, it's spring loaded, this will give you an idea of how this little sucker works. Just like it's called; The computer sends power to the electronic solenoid and this opens and closes the valve, allowing a precise amount of air to bypass the the throttle body, thus controlling the engine's idle.

NEato!! right?......................... boring.

You will see there is all sorts of black carbon built up on the little plunger inside the IAC.

-Spray a ton of carb cleaner into both sides of the IAC, let is soak for a few seconds. Get out your q tips, about 30 of them. Get busy, careful, you dont want to leave a ton of cotton behind. Make sure you open and close and turn the plunger several times while cleaning so you get the carbon off all 360 degree's of the round little sucker.
-let it dry, for a long time, make sure it is bone dry before you put it all back together.
-Dont be afraid to use the flashlight, look in there and make sure you got all the crap out.
-Put the electric solenoid back on the valve body with the two phillips screws.
-Put the gasket in place and bolt the IAC assembly back onto the upper intake
-hook the wiring harness back up
-go drink a beer
-re-connect the - battery cable

Fire up your 4.0L and notice the high idle, this is because you reset the EEC's memory and the engine now thinks it;s a new truck and it;s ready to re-learn the signals being sent to it from your now clean sensors (dirty sensors send different signals). Take the 4.0L for a nice leisurly drive, no hard core wheeling, no bracket racing, no jumping, just nice stop and go driving, this gives the computer a chance to re-learn and get you back in smooth operation in no time flat. When you get back most of your hesitation, loss of power, and rough idle problems will be gone, unless your fuel filter and throttle body are dirty, but thats another chapter...

I clean my IAC and MAS about once a year, the MAS sometimes a little more if I have been driving in the dirt alot, of course I'm **** when it comes to my truck so you might think I;m a little wacko, especailly after the beers you just drank..

 

I had a funny problem with my 97 V8 AWD. Bought it used, and didn't realize how lacking in power it was until I started towing my covered trailer. Before I got to checking things out, the gas pedal broke off the firewall. The bracket was held by two spot welds that had come loose. After reattatching the pedal, the truck has a LOT more power. Apparently, I never had full throttle before then. - something to check.

 

Hey Good tips!!! thanks a lot

Next monday i´ll tell how it goes on my sport 99!