4.0 sohc falling on it's face for a millisecond...?

[FPGT24]

I have the same problem with my '92, it only happens when I'm low on gas and make a hard left turn. So I think that's your issue. Are you getting low on gas? Try filling it up and see how it goes.

I had a tan 98 SOHC a few years ago that would completely shut off when ud make a left turn when low on gas. But no, I don't believe that to be the issue with my current exploder as everytime it has done it, its when there is more than half a tank of gas. It has never cut out when it was low on gas or below half a tank. I immediately thought fuel related when it started doing it, but when i pulled out 3 times from a dead stop and it did it i figured its likely to not be fuel related.

 

[FPGT24]

All I can say is your symptoms are the exactly the same as I had and it never threw a code. From the research I've done, the DPFE sensors are a weak link and often fail in the 30,000 - 50,000 miles range. You just could try unplugging the electrical connection and leave the DPFE in place and see what happens with your symptoms. It will likely throw a code but if the cutting out goes away you have your answer.

I'm gonna replace it soon. Since i posted this thread, my explorer has not cut out again. I just don't get it....I have never seen an issue like this....and I'm a car dealer that has sold hundreds of cars over the years i've pretty much seen it all.

 

[FPGT24]

I have a pristine 98 EB 4.0 SOHC with 72,000 miles with the exact issue you describe. In my case, the ambient temp has to be warm, like about 70 for it to appear. Rail fuel pressure fine, changed plugs, wires and pack - injectors cleaned new fuel filter still has the hesitation. SO -- I will put my attention to the DPFE now. Thanks for the input.
Oh -- and no codes!

Let me know how it turns out for you. Does yours do it often? Mine comes and goes. Since i posted this thread it has not done it again. It's scary because I use this truck to commute and for road trips where I usually do not have phone service. I feel as if i cannot trust it like I did all my other explorers.

 

[Mustang Guy]

I'm gonna replace it soon. Since i posted this thread, my explorer has not cut out again. I just don't get it....I have never seen an issue like this....and I'm a car dealer that has sold hundreds of cars over the years i've pretty much seen it all.

Yup, mine once went 2-1/2 weeks between episodes but usually it was every 3,4,5 days or so and it never threw a code. One time I almost got rearended and that was the real frustrating thing. From all my research this is definetely a symptom of a failing DPFE sensor. Hope you get yours sorted out, I know it was driving me nuts chasing the fix.

 

[mic98xlt]

"my explorer has had some strange electrical gremlin since i got it, the 3rd brake light flickers when the truck is off and just sitting there, but it is steadily lit while the engine is running (not bright as if someones on the brakes, but just enough to see it). and the other strange electrical issue it has is the locks do not automatically lock, except sometimes ill be driving down the interstate and when i put the turn signal stalk to the right, the locks will then lock. i have LED brake lights in the truck, but removing them did not help solve any of these issues."

The gremlins with the 3rd brake light is coming from the replacement LED's in your tail lights. The normal resistance of a standard light stop light bulb circuit is enough resistance to stop or ground out the stray electrical current. The replacement LED's have very little or almost no resistance which is why others have placed a physical resistor in the circuit to imitate the resistance of the bulb filament. That stray current is being physically seen in the 3rd brake light that is causing what I believe is a feedback current loop.
I had the exact same 3rd light gremlin when 2 rear stop lamps burnt out in the rear of my '98 Exp. The 3rd brake light on the '98 - '01 are composed of LED's unlike the earlier '95-'97's. I know this sounds strange, but it is true.

 

[murkinstock]

I had a tan 98 SOHC a few years ago that would completely shut off when ud make a left turn when low on gas. But no, I don't believe that to be the issue with my current exploder as everytime it has done it, its when there is more than half a tank of gas. It has never cut out when it was low on gas or below half a tank. I immediately thought fuel related when it started doing it, but when i pulled out 3 times from a dead stop and it did it i figured its likely to not be fuel related.

Ah, okay. Very interesting.

 

[C420sailor]

Mine has done this for years. It's random, and fairly rare---always accelerating from a stop in 1st gear. Did an engine swap and replaced a ton of stuff while in there a few months back and the new motor does it too. No idea what it is---engine runs flawlessly with no codes. :/

 

[FPGT24]

Mine has done this for years. It's random, and fairly rare---always accelerating from a stop in 1st gear. Did an engine swap and replaced a ton of stuff while in there a few months back and the new motor does it too. No idea what it is---engine runs flawlessly with no codes. :/

Must be electrical then, thats pretty F'ing scary...

 

[bluestream1]

i have a well cared for 98 explorer with the 4.0 sohc that i got from the original owner who was an old man. bout 3 weeks ago i was making a left hand turn....within a second or so of getting back on the gas, the engine just fell on its face for a split second as if someone had turned the ignition off, but it fired back up almost instantly. a week later, it did it again, again when making a left hand turn and getting back on the gas. the past week however, it has done it 3 times, all of these times were when i was pulling out from a stop. i have no idea what is causing it, but it is a serious cause for concern as today as i was pulling out in front of cars it did this, and worse than ever none the less. the engine again came back on, but this time it had absolutely no power for like two seconds....pretty scary..

my explorer has had some strange electrical gremlin since i got it, the 3rd brake light flickers when the truck is off and just sitting there, but it is steadily lit while the engine is running (not bright as if someones on the brakes, but just enough to see it). and the other strange electrical issue it has is the locks do not automatically lock, except sometimes ill be driving down the interstate and when i put the turn signal stalk to the right, the locks will then lock. i have LED brake lights in the truck, but removing them did not help solve any of these issues.

anyone have any clues as to whats going on? any advice or help is appreciated.

Was it snowing when this happened? I had the same issue, and it took 2 years to connect the dots...if you use an aftermarket air filter, snow flakes can get into the intake and they hit the MAF sensor, causing a one second stumble/misfire. Motorcraft air filter fixed it as they have a larger rubber lip on the filter to seal air box.

Finally found this thread:

http://www.fordrangerforum.com/4-0-sohc-4-0-ohv-tech/18901-random-misfires-snows.html

This Filter has the needed larger lip to seal air box

Typical after market filter with a flat lip seal. This is a Mann, and will cause lots of problems in winter

 

[FPGT24]

Nope, was warm out about 55-65 degrees when it happened every time. It hasn't done it again since I made this thread on here. I had replaced the air filter with a high end Purolator one like 3 weeks ago. It's getting an aftermarket intake soon.

 

[C420sailor]

Must be electrical then, thats pretty F'ing scary...

Yeah, must be. The fact that it's not exactly rare in the 4.0L SOHC Explorers (I've heard of it before, same exact circumstances) makes me think it's just some perfect storm of conditions, holes in the swiss cheese that line up, and makes the computer **** itself for a split second. Other than that the engine runs like a swiss watch, so I'm not too worried.

 

[FPGT24]

Yeah, must be. The fact that it's not exactly rare in the 4.0L SOHC Explorers (I've heard of it before, same exact circumstances) makes me think it's just some perfect storm of conditions, holes in the swiss cheese that line up, and makes the computer **** itself for a split second. Other than that the engine runs like a swiss watch, so I'm not too worried.

I wonder if Ford knows about this cutting out issue. I don't have the patience to read through the humongous list of TSB's for our Explorers to see if they issued one for this problem.

 

[bluestream1]

I wonder if Ford knows about this cutting out issue. I don't have the patience to read through the humongous list of TSB's for our Explorers to see if they issued one for this problem.

Ford has long ago moved on from these 2nd Gen Exploders...They have bigger fish to fry!

 

[FPGT24]

Ford has long ago moved on from these 2nd Gen Exploders...They have bigger fish to fry!

Obviously....but I mean i wonder if they ever knew about the cutting out issue. If anyone reading this has/had the patience to read the TSB's and found anything to do with this issue, let me know.

 

[Mustang Guy]

Obviously....but I mean i wonder if they ever knew about the cutting out issue. If anyone reading this has/had the patience to read the TSB's and found anything to do with this issue, let me know.

Like I replied very early in this thread, a defective or failing DPFE Sensor causes this exact symptom. I know because I chased this exact problem on my 4.0 SOHC. It doesn't throw a code and is intermittent so it is very difficult to track down. Buy a real Motorcraft one (do not buy the cheap knock-offs from AutoZone or Advance Auto) and it only takes 5 minutes to change it out and solve your problem.

 

[bluestream1]

Obviously....but I mean i wonder if they ever knew about the cutting out issue. If anyone reading this has/had the patience to read the TSB's and found anything to do with this issue, let me know.

There is no TSB

 

[C420sailor]

I'll try replacing the DPFE sensor. Thanks.

 

[bluestream1]

I'll try replacing the DPFE sensor. Thanks.

This may help you Son:

http://easyautodiagnostics.com/ford/4.6L-5.4L/how-to-test-the-egr-system-3

 

[Mustang Guy]

This may help you Son:

http://easyautodiagnostics.com/ford/4.6L-5.4L/how-to-test-the-egr-system-3

That's a great resource. Unfortunately, what they don't cover is that a defective or failing DPFE Sensor very often creates short duration intermittent problems. It can test perfect one minute and have an intermittent failure the next. That's the nature of the beast with these sensors. For less than $40 you can purchase a new Motorcraft DPFE sensor from Amazon and eliminate it as an issue.

 

[2000StreetRod]

cruise control

Does the brief hesitation occur with the cruise control off?