1991 Ford Explorer Eddie B 4X4

[L.A.X]

I purchased a 91 for $500.00. I'm looking to get it running like it did in when it was driven off the showroom floor. I've been doing everything I can on the Ex by buying on craiglist, ebay, junkyard and bartering. I'm a father of 3 kids, 2 high schoolers so my budget is tight. This is what's been done so far. New fuel pump, cleaned gas tank and lines. New water pump, radiator, hoses, brakes, TPS sensor, cleaned MAF, throttle body, plugs, wires and removed AC. I want to take the truck on a long trip. This truck has always been stock so the majority of parts are over 20 years old. What is essential to change as far as sensors and components are concerned? The engine is running strong and the transmission was rebuilt in June 2012. I recently removed the condenser and added a transmission cooler from a F350. This is one of the best websites ever. Thanks for all your input.

 

[L.A.X]

The engine is the 4.0 with automatic transmission, auto hubs with push button 4x4. I do all the work myself.

 

[awood]

In my 94 (still a 1st gen), I replaced the O2 sensors while troubleshooting a check engine light. It didn't fix my problem, but it seemed to run better. After fixing the check engine light problem, I took it in for emission test. The tech commented on how good it was running and how good the emission test went.

I understand the O2 sensors degrade over time, and I believe the new ones helped the engine perform better. But someone with more knowledge may want to comment here....

They were pricey to replace, but I'm glad I did.

 

[Jason94sport]

If it's running good & isn't giving you problems I see no need to change anything just because. Do the things you should check before any long trips, cooling, oil, brakes, tires, etc.

 

[Tony H]

I put 336K miles on my '91 and I didn't do half of that and it was running great when I sold it for $1500.
I'd look at other things. Brake line rust ( Rear , Drivers side) Front axle and driveshaft 'U' joints, raer axle seals... stuff like that.
P.S. this was my long range runner. This car was the one the family took to run up and down the East coast from Florida to Maine.

 

[L.A.X]

How much for OEM O2 sensors? What cars did Ford use the 4.0 on? Are heads, other parts interchangeable with my 91 block?

 

[Jason94sport]

Heads are tricky. You have a 91 so heads are weak. This is why I said coolant. If you overheat just once ever so slightly those 91 heads will crack or blow gaskets. The 94 heads are far better & then the 95-97 heads even more so. The engine was used in explorers all the way to 01. It's just the basic Ford 4.0L OHV engine. Rangers used it too.
The differences are in emissions components in later years. 94 started EGR, & some minor changes on the intake.
Think I paid around $60 for each 02 sensor.

 

[L.A.X]

I've been paying really close attention to cooling issues. The cooling system received extra attention.