Rough running and Spark plug question

[JTH1972]

So, my explorer was running totally fine up until a couple of days ago.

Now it runs rough when idling and at lower RPM's (under 1500), I have a hard time getting it to go over 90km/h, and doesn't have the power it did before (very noticeable on hills). In the drivers seat, the sound of the motor is just not the same. Engine light isn't coming on. Ideas?

Also I'd like to eventually change the spark plug wires and plugs, but how on earth do you get at the plugs on the passenger side with all that crap in the way!

Thanks

 

[92exp4x4]

You must bend and contort your body in ways never imagined by god or the laws of physics.... oh you said Explorer, not Aerostar

They are not that bad, get a long handled ratchet, some extentions and those cool flex joints. It is much easier to remove the front wheel and get to the plugs through the wheel well.

I would first check for codes (they will not always light the check engine light) and repair any problems you find then, do a major tune up. I replace the plugs, wires, PCV valve, air filter, fuel filter, and add some fuel injector cleaner to the fuel tank. Clean the MAF sensor and poke around under the hood looking for any vacuum hoses that are broken or missing.

Is your truck pinging alot under a load or heavy acceleration? Any other unusual noises?

 

[JTH1972]

Checked codes and nothing came up with KOEO.

Got the wrong PCV (hose angle isn't right) so I have to get a new one. Already cleaned the MAF a couple weeks ago. Got a new air cleaner around the same time. Been thinking of getting new plugs and wires so this is probably the best motivation.

For plugs: I heard Motorcraft (which means going to the dealer, so not happening) or Autolite plugs were best. What about NGK?

Any recommendation for wires? I was thinking of trying the Aurora's. Pricey, but reviews are supposed to be good.

No pinging under acceleration, or not that I've noticed. No other unusual noises besides it just not sounding right, Can't pinpoint a description. I did notice the other day, a rich smell when I got out of it. Since it happened suddenly. I'm leaning more to the idea of a dead plug or plug wire.

 

[awdsixbolt]

i never took anything off or used flex sockets, you just have to dig up under your ac a little and push your hand in with a socet wrench and hte 5/8s socket,
my x ran pretty much the same way when i bought it, changed the plugs wires and put some seafoam in the gas tank and the oil ran it for about 15 mins and then changed the oil, havnt hada problem since.

 

[JTH1972]

thanks for reminding me about the seafoam. I used it once already but I want to try a couple applications on it to really get the carbon out. I'll add it to the oil before a change, and I got to fuel up today anyway so I'll add some to the tank for the hell of it.

 

[shaggymane]

one easy way to check plug wires is fire it up in the dark. See if you have lightning under the hood.

the other way is check the resistance is with an ohm meter. should all be close and I think the actual number you want is no more than 7k per foot

Another simple thing to do is AFTER INSULATING your hand, pull each plug wire off and see if/which ones make no change if the way it runs. When you find one that makes no change pull that plug and look.
If the plugs good swap a wire to that cyl and so on. Process of elimination

good luck

 

[JTH1972]

Noises: I'm hearing like an extra "puffing" noise coming from somewhere I haven't been able to pinpoint yet. I may have to try to get under to take a look. possible exhaust leak? Speaking of which, exhaust smells rich and my fuel consumption has gone to crap. There's a point in my gas gauge that I know I should be around 180 to 200 km mileage when I hit it, but I'm only around 120 km.

 

[shaggymane]

yeah, puffing is good indication of an exhaust leak, either head to manifold or manifold to down pipe.
Do you have experience with ford exhaust manifold bolt removal?
I guess the first thing to do is check and see if any bolts are loose. it happens occasionally.


the first sign my FPR went bad was getting 160 mi to a tank.

Ok, you cleaned your MAF but did you test it with a DVOM?
"with the engine at idle, use a DVOM to verify that there is at least 10.5 volts between terminals A and B of the MAF sensor connector.
then measure the voltage between the MAF sensor connector terminals C and D, if the reading is approximately .34 - 1.96 volts, the sensor is functioning properly

 

[JTH1972]

yeah, puffing is good indication of an exhaust leak, either head to manifold or manifold to down pipe.
Do you have experience with ford exhaust manifold bolt removal?
I guess the first thing to do is check and see if any bolts are loose. it happens occasionally.

None whatsoever. Tips are appreciated. I can still hear a puffing, but I think it's from the muffler. Still got a shield around it so I assume it's still the original one.

Ok, you cleaned your MAF but did you test it with a DVOM?

No, but thanks for the info. I'll check that when I get a chance.

Plug wires, plugs, and fuel filter I'm picking up today. Local parts stores don't carry Autolite or Motorcraft so I have to get the NGK's. Plug wires are Blue Streak.

Now the weird part... after the last post from you, I go and start the Exp and it sounds like it's running almost normal again. Still a little rough but not as bad as it's been. Not 100% return of power but better than I've been getting, and fuel economy has improved, but not as good as it was. It still runs rough under load when it's in OD over 80 km/h, little smoother on flats or downhill. Thing is, I haven't done a damn thing to it by this point!

 

[JTH1972]

Update: Culprit looks like it was a dead spark plug wire, or so I thought anyway.

It seemed to run a bit better, but it's still nowhere near the mileage i used to get when I first got it barely a couple of months ago. Plugs, plug wires, PCV changed. I was going to change the fuel filter, but the crappy tool I bought doesn't work worth a damn. Fuel filter looks in really good shape anyway (esxternally). I have some power back, but it runs very rough with motor under load (even up slight hills) and under 1500 rpm. You really notice how rough it is when OD kicks in, and doesn't smooth out until at least 90 to 100 km/h, until the rpm's are over 1500. Fuel economy is crap too. It's still perplexing as this all seemed to happen overnight.

I've also ran Seafoam through the tank, and a couple of times through the vaccuum before the plugs got changed.

Oil pressure gauge tends to jump around too. bad sensor?

any further suggestions on what to test next?