Tonight's new problem with the Explorer!

[Zorin]

So, this thing typically runs about as well as a Swiss Watch, so problems make me scratch my head.

When I joined this forum a little more than a year ago, the Explorer had 112,000 miles on it. Now it has 140,000 miles, and we are starting to see some minor issues. Today, we had a good one.

It started as I went to merge, and I kinda floored it. Almost as I got to full throttle, it bucked SUPER hard...hard enough to bark the tires, and I was already doing about 40 MPH. After that, the wrench light in the dash came on, and the Trac light came on. It didn't die, or stop running, or even seem like it wanted to quit. I kept driving, and started playing with it....anything over about 75% throttle produced some bucking, nothing serious, definitely nothing like what had occurred.

I got home and went to drive it up a slight hill to my garage, and it really didn't want to go up the hill. My wife told me the front wheels were skidding on the ground (it's icy out right now) instead of spinning or turning. I kicked it into 4H, and pulled gently up to the garage, and it seemed down on power. Grabbed the Bluetooth scan tool and plugged it in before shutting it off, and this is what we got:

So, conventional wisdom tells us this is probably coil packs, and at 140K miles, it probably is time for a set. After a restart, there was no more wrench light, no more Trac light, and the engine had full power.

I don't dispute some coil problems, however, every single cold start when I go to leave, it kinda jumps a little as you give it gas...lurches, if you will. It only does that the very first time you give it gas, on a cold start. So I am also wondering if I am having electronic throttle issues as well. I have previously put an electronic throttle on this car for the previous owner, and it was having a bucking concern at that time as well. However, it had no wrench lights, no MIL's, and the only way I could tell that was the problem was by comparing the accelerator and throttle sensor readings.

What say you?

Thanks again for reading my lengthy post!

Tim

 

[dacaur2]

Im not sure where you are getting coil packs? The only code I see there of concern is B1318, which all I can find is "battery voltage low" at the module?
Personally, based on your description, I would look for chafed wires or bad grounds first, then I would suspect the ABS system based on barking tires and the fact that the fronts were skidding up your driveway, maybe the brakes were holding them back?
Of course this is all just opinion, im no expert.

 

[Explorer_PL]

Seems like my problem:

6R60 communication errors U0101, U1900 - solution.

 

[dacaur2]

Hmm, well, then I guess the coil packs are worth looking at. I just discounted the U1900 because that can be set simply by plugging in a reader while the engine is running, which he said he did....

 

[Explorer_PL]

Yep, in my case I had no misfire codes, but set of new Motorcraft coils and plugs solved the issue.

 

[Gorb]

Given the mileage you should check the tone rings too. They're located at the end of each axle shaft right where it meets the hub, and look like a toothed gear. Those are what the abs/traction control system uses to detect wheel slip so if one is broken it'll cause problems. If you do find one broken or missing teeth dont drive the vehicle... the anti skid system will activate randomly and could cause a wreck.

Here's a way to test your ignition system while driving. This method puts strain on the engine without revving the piss out of it

1. Get up to highway speed (65 mph or so)
2. Lightly ease your foot into the gas, trying to gain maybe 50 to 100 rpm. Just enough to bog the engine out but not enough to make the transmission shift.
If your ignition system is real bad the truck will start banging and bucking.

 

[Zorin]

Just a follow up for you guys -

I installed Forscan on my laptop last night, and started playing around PIDS, and pulled up Mode 6 data. Interestingly, it has a function where it records the last ten drive cycles, and it showed a lot of misfiring on all but cylinder 1. So, I pulled all of the coils, and all but cylinder 1 were factory coils, and they all had blistered tops. Cylinder 5's coil had a physical crack right where the connector was molded to the main body of the coil. Cylinder 1's coil was a Masterpro (O' Reilly brand) that some owner years before myself or the previous owner had installed, and it still appeared serviceable, and passed an ohm check.

I was in a crunch, so I bought an 8 pack from AutoZone, not my first choice, but we'll see how they do, and they are lifetime warranty. I know my spark plugs are good, they were changed about 35,000 miles ago. If they act up, I will get an oscilloscope, and watch the CAN voltages to see if they are introducing noise into the CAN harness, and if they are, I will have Autozone here order me Denso coils (these are who Ford gets the Motorcraft coils from), and replace them all with Denso.

I will drive it a few days, check it out, and re run the Mode 6 data to see if it's cured, and report back then.

Gorb, as to your past post, it would do exactly that, but you would have to get to 75% throttle before it would begin to buck, or cut out.

Tim

 

[CharlieK9]

if it is low battery voltage it could be the ECM relay dropping voltage. An easy test is to swap it with I believe the starter relay.

 

[Zorin]

Charlie,

The battery is 5 weeks old, and I could find no other voltage related issues. The alternator is putting out 13.9 VDC at idle as well. I'm pretty sure the B1318 was set 5 weeks ago when we were cranking on it in the shop, and the battery got cooked, and went severely under voltage.

 

[WaltZ]

Thanks Zorin. Looking forward for the report on the Autozone coils.

I've been having similar issues. Some hesitation around 45mph. In the past, it was usually a dirty MAF sensor or bad coil. Currently, no codes.

5 of the coils are originals and all the plugs have 60k miles on them (3rd set). I just ordered Autolite HT1's from Rock Auto for $6.XX a plug and a rebate. If your Autozone coils work out, I'll head there and pick up an 8-pak. I like the lifetime warranty.

 

[Explorer_PL]

Last week I replaced all coils and plugs with Motorcraft parts that I got of eBay for $ 250
Truck runs like new, and no kicking or bucking.

 

[dacaur2]

so what kind of mileage are we looking at here before these things start going bad (coils)? Im at 130k now, just wondering if I am already in danger territory or when I should start to worry...

 

[Explorer_PL]

The ones I replaced (Motorcraft as well) lasted 60-70k miles. But I work the engine hard, really hard at times so maybe that what shortens their life.

 

[Zorin]

My original 7 went to 140K. Now, that said, it had been having the very random buck that I was thinking was a throttle motor expiring. It also had a few other little niggles, like a very random choppiness when giving it the gun on a long stretch, as well as a lurch that would occur on the very first accelerator press of the day, but never afterwards.

All of these little demons were exorcised with the new coils. So far, after about 200 miles, the Explorer is running tip top, however, I have not hooked up the computer to see if anything has reset or anything like that - but no wrench lights, no Trac lights, no MIL, nothing to suggest there may be.

Tim

 

[Zorin]

UPDATE on the AutoZone coils -

We're now at nearly 145,000 miles, and the coils are still performing beautifully, as is the rest of the truck.