95 w/4.0 OHV - low idle, low power, rough running, gas smell

[Alexander Ward]

Hello Everybody,

I recently purchased a 1995 Explorer Limited with the 4.0 OHV engine. It was running smoothly with lots of power, but then suddenly during a cold start, I heard a loud pop and then it began running poorly, with a low, lumpy idle, a significant reduction in power, apparent misfiring, and a noticeable smell of fresh gas. The gas mileage dropped to about 7 MPG. After driving for a while and stopping, there is a burned smell. The CEL comes on occasionally for a short while when driving uphill under load but then goes out. No, I haven't pulled the codes; I don't have a code reader and I haven't yet had the opportunity to drop by to AutoZone to ask them to check.

Looking at the engine, I noticed a dangling wire on the left side of the engine (looking from the left front and pulled it up to see what looks like a sensor of some type. the picture below shows the wire and sensor(?):

I do not see where this should be attached. Can anyone tell me what this is and where it should go? And if this popped out, would that cause the bad driveability?

Thanks in advance!
Alex

 

[poker4me007]

It's a air intake temperature sensor it goes into the air intake, in between your air cleaner and your throttle body...you'll have unmetered air going in the motor, probably causing it to run bad...

you should see a hole there just pop it back in, see if that helps, don't know how it poped out maybe you have other problems also...

 

[Alexander Ward]

Oh, Thanks! I'll put it back in again in the morning and see if that helps. I have a service manual for a 1996, but it didn't help much; I'll go back and re-read it.
Alex

 

[IronCurtain]

I also have a 95, it's an eddie bauer tho. Obd2 readers don't work, as they weren't incorporated in the explorer until 1996.

You have to check the codes manually, either with a voltage reader, or in some cases, the cel will flash giving the code readouts. The process is as follows..... Actually I'll just upload a pic of the manual page it comes from:

The wiring harnesses referred to are in the engine bay, right next to the fuse/power distribution box, drivers side next to firewall....in my 1995 eddie bauer 4dr 4x4 v6

Hope this helps

 

[J_C]

You probably had a backfire during the start which blew the sensor out. Hopefully that's all the damage it did, minimally it could have popped other vac line(s) off, or blew the intake manifold gasket.

I am certain that having that sensor out can have caused poor running and a check engine light by itself, but as mentioned above it may or may not be the only issue. I would reinstall it, see how it runs.

If it still runs bad I might disconnect the battery for a few minutes to cause it to relearn everything then after a day and full engine warm up cycle if it's still not running well, then pull the OBDI trouble codes. Let me rephrase that, if it runs okay I would wait but if it starts running poorly I would not continue to drive it. Unburnt fuel out the exhaust can wreck catalytic converters.

 

[96eb96]

A 96 would make a world of difference, because it has a misfire monitor to detect the problem cylinder, and is full OBD-2. It is unlikely Autozone still has the old scanners, but they may. I don't believe it can show misfires. The MT 2500 red brick (which is dirt cheap on ebay), may give live data streams for this system. There is also a 25$ digital reader which does tests. I hate the blinking light method. There is also a cylinder balance test on EEC IV that will tell you the bad cylinder. Was a while since I ran that! I'm sure a 95 will have full tests and data.

Here are possibilities for smelling raw gas:
-Stuck open injector
-Stuck open injector driver in the computer
-Bad plug (in my case it was cracked, could be from coolant and a cracked head)
-Bad wire
-Bad coil (less likely, because it affects two cylinders)
-Crack in the head or head gasket.

You can disconnect wires to see which wire produces no change. That is the bad cylinder, but be careful for voltage.

To detect the latter, pay attention to the temp gauge. Does it move around or stay fixed? If it moves around(not necessarily hot) you may be putting air into the coolant. I had excellent luck with K-seal, if you find any crack issues.

 

[IronCurtain]

^ I'm going to look into those readers for sure. Yeah the blinking light method is archaic, but it works and is kind of satisfying in a weird way lol.

Here's a pic of the connectors.. Is that where these scan tools you're talking about connect 96eb?

 

[96eb96]

^ I'm going to look into those readers for sure. Yeah the blinking light method is archaic, but it works and is kind of satisfying in a weird way lol.

Here's a pic of the connectors.. Is that where these scan tools you're talking about connect 96eb?

View attachment 152706

Yes, that is the DCL and the single wire is the Self test wire I believe. That connector can read live data streams.