2001 Ford Explorer



July, 19, 2010 AT 2:03 PM

Engine Mechanical problem
2001 Ford Explorer 6 cyl Two Wheel Drive Automatic 169000 miles

Hello folks.

I have an 2001 Ford Explorer 4.0L SOHC.

My problem began several months before this actual problem, I had a CEL. After having the code read, it turned out that it was the IAT sensor. Since I believe the IAT and Maf are together on this model, I replaced the Maf, the code went away.

During this time, the Exploder was hesitating very badly, I instantly thought of the spark plugs even though I had replaced them last year. The problem wasn't with the plugs, but with the plug wire off cylinder #5, which when I popped the hood and let the vehicle idle, you could see the plug wire shaking violently. I replaced the plugs anyway with Motorcraft Double Platinum, and the wires as well.

This took care of the hesitation.

This newest problem came when I tried to start the vehicle one day. It would not start, so I instantly thought that my battery may be getting ready to die. I had a friend jump me off, and the vehicle ran fine for a couple days. Then it got to where it would stall out on me. It died on me a couple times at idle. I was driving down the road, and it turned off on me at 65mph, but instantly turned itself back on. Then it turned off on me when I was coming to a stop, and would not start for about 20 minutes.

I was doing some testing, because my ignition switch was nearly yanked out a couple years ago. I thought that the switch may have been backing itself off, and was able to confirm this 2 times. You could turn the vehicle over and eventually start it, but if you pulled toward the passenger side, or turned the switch back just a hair (not really using any pressure), the vehicle would stall. I decided I'd attempt to install another cylinder lock (This is the part I thought was damaged) and just get a locksmith to re-key it.

This got me into the PATS system. Lol I destroyed the black ring with antenna that reads the chip in your key, so I ordered a new one from Ford, and installed it. The vehicle started instantly, and ran for 2 weeks with no problem. Well, it's back to it again, this time I'm not even able to get the vehicle to start.

These are some of the things I've done.

With key in the ignition, the PATS system checks out. (Does not blink rapidly)

The CEL and other lights come on before cranking, while cranking the CEL light does go off. The starter motor engages, and cranks the vehicle. (Just to be certain, I replaced the CKP sensor.)

The Fuel Pump is running, I checked the fuel pressure when this began again. I am getting 60 PSI KOEO. KOER I am getting 62 psi, and when I shut the vehicle off, after about 6 minutes I still had 60 psi. I've also pulled spark plugs #5 and #6, and both plugs are wet. They still look good besides having gas on them, and you could tell the vehicle had been running a little rich. Probably due to the bad IAT sensor.

The vehicle has a new battery, and battery voltage is good. 12.4v I also replaced the TPS when I replaced the CKP.

I replaced the Ignition coil with a new one, and this did not help either.

I am at a loss, are there any other things I should check?

Thank you guys for reading, and any help is greatly appreciated.

I forgot to add that I changed the fuel filter about 5 months ago. The fuel that came out was a little dirty, but did not look rusty.


13 Answers



July, 19, 2010 AT 10:45 PM

If the plugs are wet, you must not be getting spark. Have you checked for spark?



July, 20, 2010 AT 4:41 PM

I was able to confirm that I got spark on cylinder #5, but the spark is orange.

I plan on pulling the rest of the wires and checking those as well.

From just the one wire though, it seems like I may have a dying coil, or maybe it is just a pack, I'm not sure yet.

I replaced the coil with a new one, but it didn't help. Maybe the coil was bad out of the box, I never checked it. I could have also been having another problem at the time as well.

I'll get back to you as soon as I'm able to check the other wires.

Thank you.



July, 20, 2010 AT 7:05 PM

I pulled 4 plugs wires, Cylinder #1, and 4, 5, and 6. I didn't pull 2 and 3 because they are a pain to get in and out.(Thanks for designing the engine compartment with the AC condensor and other things right in the way Ford!) I was also basing my thoughs on the assumption that if (4, 5, and 6 were the first wires pulled, then #1) the aforementioned wires were all doing the same thing, plug wires 2, and 3 could possibly be doing the same.

All wires did produce a spark, it was not a brilliant spark, nor was it blue. It was an orange, dull spark. The vehicle did start while we were running tests, but I immediately told her to shut it off without thinking to ask if the CEL was on. I was unable to get it to start again.

I began testing the coil, and these are the results I've come up with.

I tested to see if the electrical plug to the coil had voltage and confirmed that it did.

I then tested the primary resistance of the coil. All of them checked out at 00.6 except the third negative which came in at 00.4. Both of these are low according to Haynes.

I tested secondary resistance afterwards. Coil pack 1-5 tested at 14.05 6-2 at 14.4, and 4-3 tested at 13.78.

I then tested to see if I was getting a trigger signal from the PCM, and was able to confirm that I was.

The secondary resistances are above specs according to Haynes and with the primary resistance being as low as it is, can we assume that the ignition coil is the culprit?

Thank you for any and all advice.



July, 20, 2010 AT 11:25 PM

You've done your homework. Based on your information, that is what I would lean toward.

Let me know if it takes care of the problem.



July, 22, 2010 AT 7:49 AM

I went ahead and replaced the coil yesterday with a new one, and still no start.

I began checking the spark plugs again and noticed (since I've been checking these close to dark, and have a hard time seeing anyway) the plug was actually fouled.

I had bought a new set of plugs the other day so I went ahead and replaced them. Afterwards, still no start.

I then began pulling plug wires and testing resistance. The 2 foot plugs were only getting 4,000 ohms, and the longer ones closer to 3 foot were only getting 8k ohms.

Since the wires were under warranty, I took them back and got another set. I then replaced all of them and tried to start the motor. No start. I tested these plug wires, and they're just the same as the others.

I decided to see if I was still getting fuel pressure, and began with KOEO. No pressure, so I attempted to turn the motor over, and I got 58 psi. So I thought that the fuel filter may be clogged. Pulled it off and let the fuel drain. The fuel looks fine, no rust or dirt. I've put some Gunk fuel system cleaner in it to see if there is water in it. I then blew the fuel filter out to make sure that it wasn't clogged and put it back in. KOEO fuel pressure went to 62 psi. Since I'm unable to get it to start at will, I was not able to confirm any other part of the test, except testing the fuel pressure regulator. After 10 minutes I still had over 55 psi.

I have been able to get the vehicle to start a couple times, and it runs like there is no problem. There are no DTC's. My wife noted that while attempting to crank the vehicle over, there is a white cloud of smoke that comes from the tail pipe.

I've noticed that when attempting to turn the vehicle over for more than 5 seconds, the Alarm light for the PATS system begins flashing rapidly. If you do not have the key turned over, or the key out of it, etc, the light flashes every 2 seconds like normal. It is just while cranking.

History on the PATS system: Besides the antenna being broken on the PATS sensor, I had been turning the key over and over, attempting to prime the fuel pump (hard to hear sometimes where I live). I noticed that the PATS light began flashing rapidly. To make a long story short, I fear that I may have deleted the code in it. But it ran fine for 2 weeks after I got it started again, so I don't know what is going on.

I'm sorry I didn't get back to you yesterday Jacob, I had a pretty long day.

At any rate, I thank you for your input, and really appreciate all of the help.



July, 22, 2010 AT 10:41 PM

If it is flashing, that is shuting it down.



July, 24, 2010 AT 11:55 AM

I was able to confirm what the PATS system did to the vehicle when my old sensor was tore up. As soon as you turned the key over, and attempted to crank, I believe that it cut power to the starter. I couldn't remember if I heard the fuel pump relay click or not, or if the pump would whir.

This is not the case in what is occurring now. The vehicle turns over, and after about 5 seconds the Alarm light starts to flash. I believe after 3 seconds power to the fuel pump is cut anyway, or is that just KOEO?

Do you think I should just call a locksmith to take a look at it? We've had one out here before, most of
them do have the tools to work with the PATS system. They also charge a lot less than the stealership in most cases.

Thank you for your help.


This is what is messing with me so badly. I cannot replicate what this vehicle does. Now the PATS system is checking out fine. I got it to start once, there is some whining (sounds like it is coming from the front end) that I'm thinking may be from the new CKP. It has some plastic ends on it to position it away from the teeth on the end of the crankshaft that are supposed to wear off. However, I leaned on the plastic intake and the vehicle shut off. I changed the upper and lower intake gaskets a couple years ago, and it isn't acting like it has any vacuum leaks.

I'm starting to think that it may be time for the bone yard.

By the way, I just noticed in your other posts that your name is Joe. Sorry for calling you Jacob, and thanks for all of your help.



July, 24, 2010 AT 10:16 PM

First, thank you for the positive feed back. It is appreciated. Second, Jacob is my son's name. I have two sons, jake and nick. That is where my user name came from. I get called that all the time.

Take care and let me know if I can help you with anything in the future, and thanks again.




July, 25, 2010 AT 7:12 PM

You're welcome for the feedback. You've been very helpful, friendly, and very knowledgeable; just like the feedback said.

I believe I'm going to go ahead and turn this one over to a mechanic tomorrow. It's been too much of a headache. I've tossed some parts on it that I probably didn't have to, but at least they are new now. Most importantly though, I really need to get it running.

I'll continue coming back and help you guys answer simpler questions. That is if you guys don't mind. I've gotten pretty good at working on vehicles, but I fear mine has more to do with electrical, and I'm just no good with schematics.

Congrats on the children btw.

It was a pleasure working with you on this one, Joe, as soon as I find out what is wrong with it, I'll let you guys know.

Thanks again.



July, 30, 2010 AT 8:25 PM

Okay, I still haven't turned this one over to a mechanic yet.

Recently I've been able to get the vehicle to start, it just runs really rough, and smells really bad. You could smell something burning up front, but I'm thinking this is the plastic spacer on the CKP that is being burnt through. I do have some codes now.

I have a P0103, P1151, and P1131.

I was able to freeze the data on the P1151 code.

Engine Speed (RPM) 1781. You have to keep your foot on the gas to keep the vehicle running. Also, to start it you have to have it at WOT or close to it.

Calculated Load % 44.3

Coolant Temperature 163

STFT bank 1 -23.4
LTFT bank 1 -0.8

STFT bank 2 42.2
LTFT bank 2 0.0

Vehicle Speed 0

Fuel System 1 Closed
Fuel System 2 N/A

I believe that this vehicle is from California, and it looks like it has 2 catalytic converters to me. I've tapped on both of them with a rubber mallet, and I've got a little bit of jiggling around; nothing major.

I also noticed that the elbow right before what I think is the first catalytic converter was red hot last night.

I see that P0103 is high input from the MAF sensor, although I really don't understand what that means. Is it trying to lean the fuel mixture out more because of air? In the first post I mentioned that I changed the MAF because of the IAT sensor. Is anyone able to confirm that the MAF and IAT sensors are combined on this vehicle?

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