4.0 sohc fuel injector questions / help for those with brakes locking | Ford Explorer Forums - Serious Explorations

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4.0 sohc fuel injector questions / help for those with brakes locking

2006 eddie bauer

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March 8, 2019
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06 explorer E B 4.0
Hi, all. New member here with a few questions for the pros, but I wanted to offer my experience on an ABS issue for those who may be having a similar problem. I recently purchased a 2006 Explorer EB 4.0 with 125K miles in need of some repairs for my soon-to-be 16 year old. The car appears to have been kept very clean, but I am starting to see some signs of maintenance neglect. My experience is 30 plus years of advanced shade-tree mechanics.

The initial repairs were thought to be in the 4 wheel drive system, but as it turns out the problem was with the ABS causing the traction control to apply the brakes and essentially not allow the vehicle to move because the engine's power was not enough to overcome the force of the brakes. The problem ended up being a left rear wheel speed sensor that was defective. The wrench light, abs light, and traction control lights were all illuminated on the dash. The dash display was illuminated in yellow at this time. I am fortunate enough to have a reader that displays ABS codes, so I plugged it in and found 5 codes for ABS. 2 for the right front wheel 2 for the left rear wheel, and one for pump failure. I had removed the ABS and traction control fuses when we were trying to diagnose the issue, and I am confident that this caused the pump failure code. I recorded the codes, and cleared them with my reader. The code for the left rear sensor reset itself every time the key was turned to the ON position. I followed this code, and was able to go right to the sensor that was throwing the code. I then checked the resistance of the sensor which was in range. I then checked DC voltage at the harness end of the sensor plug. Showed 11.95 volts with the key off, and 12.7 with the engine running, so I didn't suspect a wiring or an abs module issue. I then blocked the front wheels and jacked up the wheel in question and had a helper spin the wheel with the vehicle in neutral while I was checking the AC voltage output at the sensor and found no voltage. Replaced the sensor, and everything went back to normal. No lights on the dash, and the display returned to green. I just wanted to offer this for those who may be having the same issue, and give some encouragement. It is a fairly simple repair with some basic skills and tools.

Now I need some advice.

The vehicle had been driven daily until the ABS problem occured, and it had sat for a month before I got it so this next one came as a major surprise. In my opinion, the engine cranked a little too long before starting, and the starter did not stay engaged long enough to start the engine on the first try. I was writing it off as low battery voltage from sitting, but I think the starter bendix is a little weak also. This is a problem that I will be addressing soon.

I was trying to start the engine, and after a couple of crank cycles, the engine backfired. I opened the hood to see what had happened, and found the intake plenum blown apart! After my initial confusion I went to a local salvage yard and found a new used intake. Got new gaskets, a can of throttle body cleaner, and a new throttle body mounting gasket. This afternoon I removed the broken intake. At this point I noticed that the intake ports in the heads were all black, except for #6 (left rear) and it was a light brownish color. It appears to have a lot of raw fuel residue (not puddling) in the combustion chamber. I had my helper turn the key on to cycle the fuel pump, and saw no blatant fuel leakage. I disabled the coil pack, and had my helper briefly crank the engine as I watched the injector spray pattern. #6 is throwing a wall of fuel into the chamber, 4 and 5 appear to be evenly misting about 1/4 as much as #6. I am fairly unfamiliar with electric fuel injection systems.

I guess my question is if anyone has performed this repair how did you go about it...
1 injector or all 6?
remanufactured or used?
is there a preferred brand? (thinking Motorcraft is actually Bosch manufacture?)
are there any other issues that would cause this to occur?
There is no fuel in the vaccum line to the fuel pressure regulator to indicate a bad diaphragm.

Hope I have not been too wordy, thanks in advance.

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Fuel injectors are not normally considered a maintenance item (especially not at 125k miles), and are little spendy. I wouldn't recommend replacing all six unless you have an extra $200 laying around.

I don't think the 4th gen injectors are Bosch OEM (I know the 3rd Gens were, and have purchased them). Your best bet @ rockauto is this: STANDARD MOTOR PRODUCTS FJ818 ($34 plus shipping). The Motorcraft part looks identical, has 12 mos. shorter warranty, and is $20 more.

Be careful with the upper and lower O rings. Lube them with something (WD40?) and careful when you replace the injector. I've had leaks after I put everthing back together, which is no fun. Good luck.

....Oh, and run some serious fuel injector cleaner through the tank--like Techtron (available by the case @ Costco) or possibly Seafoam.

Thanks Drewmcg

Sorry for the delayed reply, I have been working double shifts for the last few weeks, and just have not had much of a chance to reply. I ended up getting a complete set of reman injectors for $100. You hadn't posted by the time that I purchased the parts. I noticed that there was some seepage from one of the upper o-rings on bank 1, and I wanted the flow and spray to be balanced between all 6 cylinders. Probably a false sense of security, but it seemed like the right thing to do.

I don't want to have to take the intake off again, so I decided to go this route. I also added a new fuel pressure sensor, pcv valve, spark plugs , and wires (all Motorcraft parts) and cleaned the throttle plate, and also the intake ports that are exposed with the intake off. Performed the idle re-learn, and I couldn't be happier with the results. From previous experience, I strongly believe that Fords are happier with Ford parts. I was able to source the Motorcraft items online from different vendors at comparable prices to aftermarket parts.

For anyone looking at a plug wire replacement on the 4.0, the alternator needs to be removed to correctly install the plug wires. They fit into an l-shaped sleeve thet routes them around the front of the valve cover. Spark plugs had never been changed according to the previous owner, and the gap was greater than .085". the only one that didn't break loose, and screw out easily was #1. I got a couple of threads loose, then lubed it with Kroil and screwed it back in. Did this 2 times, and it came right out cleanly. I had read that people have better luck with the engine warm, but I took advantage access that is gained to bank #1 with the throttle body not being installed yet. From beginning to end I have about 4 hours of labor in this project.

As I said in my first post, I have a new driver that is going to get this one, and we have a terrible entrance point to a very busy divided highway. I want to make this vehicle as reliable as possible. Hesitation and stumbling are not an option!

I normally use Lucas fuel system products with good luck, and never used the Chevron or Sea Foam. I would not be opposed to using either product at all. Is the Techron something that you have had the best experience with? I have read online previously that people really like Chevron gas with the Techron, but we do not have any near me that I am aware of.

Thanks again!

Nice. You may want to replace the full filter if it's been awhile (which can be a PIA), what with all that investment in the fuel system. Techtron is good stuff, but probably only worth using episodically if you use a top tier gasoline like Costco....