1994 Explorer 13 MPG average

[mcfixstuff]

I am going to test it, but a year ago, since I was unable to source a decently priced intake hose to replace my broken one I went with one of those "cold air intakes" and I use that term humorously, because there is no cold air being sucked in, to replace the broken hose and it made me delete the stock air box. Well, after a few beers this past weekend, I modified the metal pipes to fit to the stock air box, so it no longer sucks in hot engine air. My theory is that it had extra power when I cold started it, because It was sucking in normal temp air, but after the engine got to temp, it was sucking in hot engine bay temps, causing the reduced performance. So far I have noticed, there is still a decline in performance, after warming up, but not as significant. I am having a new issue that has been developing now where my car hates 35mph. The transmission keeps going in and out of gears at that speed, but all other speeds are fine. I'll make a separate post for that issue.

 

[ChildIdenticant]

The transmission keeps going in and out of gears

Mine started shifting in and out , I think at just about the same mileage (150k?). Caused by galling in the valve body. Repairing that was a meticulous task.

 

[mcfixstuff]

Mine started shifting in and out , I think at just about the same mileage (150k?). Caused by galling in the valve body. Repairing that was a meticulous task.

Could I just avoid the issue by replacing the whole valve body? They sell one on rock auto for $150

 

[ChildIdenticant]

Could I just avoid the issue by replacing the whole valve body? They sell one on rock auto for $150

Also an option.
The listing available I see on rockauto is for 189 + core mentions nothing of updates.
There were updates and upgrades to the transmission over its use. A couple to the valve body. Find out if vb you are purchasing has any done to it.

Might want to actually drop the valve body and inspect to see if the problem is the valve body physical condition, or solenoid, or something else entirely. I believe testing the free actuation of all valves can be done without disassembling any of them. There are a couple check balls though which can be lost if you aren't careful.

 

[92exp4x4]

Both 1st and 2nd gens had 5 speed manuals available.

I think even the first year of the third gen it was optional and was dropped that year. I remember seeing one on this forum at one point.

 

[mcfixstuff]

Y'all, feel free to insult me. When I changed the transmission fluid, I added too much. Draining the fluid to normal levels solved all issues.

 

[makaveli200369]

Hi I noticed you never changed the o2 sensors. I'm guessing its still original. Since these aren't obd2 its hard to get a reading of whats going on without attaching a voltmeter to it. But seeing how most of your other parts are in good health I'd look into those. Also how about the PCV valve still original? I replaced mine with motorcraft.

 

[Flashflood]

I have a question. I have dumped a lot of money into my 1994 Ford Explorer XLT 4WD about $9000 in total since I got it. 140,000 miles. I just want it to run like new. I love the truck. I am throwing no codes for KOER or KOEO, the cylinder balance test threw a 90, or a all good code all 3 times. No issues that the computer can tell. Still, however, I average 13mpg. Best I ever got was 15.6mpg, worst was 9mpg.
I've thrown so many new parts on it except for the EGR, since I never got a code, and that sh*t is expensive to just throw on just cause. I've already done new injectors, intake plenum gasket, spark plugs, wires, MAF sensor, TPS, IAC valve, and any other things.
The only symptom I have is that on cold starts it has more power than it does after it's warmed up. After it's warmed up, I notice it has about 75% of the power of a full throttle take off in first than if it was cold. Things seem looser when warm, if that makes sense. Engine gets up to normal operating temperature. Everything related to the cooling system has been replaced.
Is there something I'm missing? Is there a test I can do to figure out why I'm getting that kind of mileage? No OBD-II so I can't really read live data....unless I can and I just don't know how.
I'd love to get the 19mpg I'm hearing other people talk about in this forum.

Manual or Automatic? I can't really speak for other 1st gen owners with Automatics. But when I had my 1st gen Manual I averaged 16 or 17 city. Highway 21 I think it just depends on how tortured that engine is. Tbh. Honestly never use regular unleaded always use plus or premium when it comes to how old these things are that's where you get the mileage.

 

[mcfixstuff]

Hi I noticed you never changed the o2 sensors. I'm guessing its still original. Since these aren't obd2 its hard to get a reading of whats going on without attaching a voltmeter to it. But seeing how most of your other parts are in good health I'd look into those. Also how about the PCV valve still original? I replaced mine with motorcraft.

O2 Sensors have been replaced. Only thing I really haven't touched is the EGR system. I have no idea how to test it to see if it's working. Supposedly there's a scan tool that can give live data on the 1994 OBD-1 system. I'd love to figure out how to do that. Maybe that will tell me.

 

[mcfixstuff]

Manual or Automatic? I can't really speak for other 1st gen owners with Automatics. But when I had my 1st gen Manual I averaged 16 or 17 city. Highway 21 I think it just depends on how tortured that engine is. Tbh. Honestly never use regular unleaded always use plus or premium when it comes to how old these things are that's where you get the mileage.

The engine is actually in solid condition. Somehow, despite how sketchy the sellers were when I bought the vehicle, it burns no oil. I bought it at 127k miles. Now 147k Great compression on all the cylinders. Cylinder balance test is great. No issues. No sputter, no roughy idle. Runs like a top. Just ****ty mileage. I've put premium ethanol free gasoline in it with no improvement in mileage.

 

[mcfixstuff]

Running some experiments this morning, here's what I found:
When I unplug the Idle Air Temp sensor, the engine has more power like when the engine is cold. However, the sensor is showing the normal ohm changes when hot and cold. I might just throw a new one at it since the part costs $8.
Also, the transmission fluid did not fix the issue. I took apart the valve body to change the 3-4 shift solenoid, and the valve body was in immaculate condition. Looked brand new. no build up or anything. The shift solenoid on rock auto was not the correct one, and none of the ones looked like the one I took out of my valve body. All I did was clean the old solenoid with brake cleaner, and wished for the best. Still having the same issue . I might just opt for the remanufactured valve body's they sell on rock auto for $200.
Wondering if a faulty TPS sensor could cause the issue I'm having, since the shifting only jumps around when I'm trying to maintain a constant speed. It just loves to go into overdrive between 32 and 45mph, then it'll pop back out. Overdrive is totally fine at highway speeds.

 

[makaveli200369]

O2 Sensors have been replaced. Only thing I really haven't touched is the EGR system. I have no idea how to test it to see if it's working. Supposedly there's a scan tool that can give live data on the 1994 OBD-1 system. I'd love to figure out how to do that. Maybe that will tell me.

How about if you remove the spark plugs and read them. Are they all reading the same? Maybe one is more sooty than the rest. Could have a leaky injector. Id probably also do a compression test just so I know the base line and make sure its within spec.

 

[wankel1308]

Edit: Seems like you got it worked out! Congratulations!


I've been watching all your threads and I'm wondering if you've replaced the computer yet? I ended up needing to replace mine as the fuel injectors weren't getting signal. Simple caps in the computer go bad after 30 years New ECU improved my MPG significantly.