Power Loss??

[WoodsBuggy3]

Ok, did a search didn't really find anything that is quite like my prob, so maybe you guys can help me out. 92 Explorer, 175K, lately the fuel pump has been making some noise so I replaced it and the fuel filter, at the same time I replaced the exhaust with a cat back Flowmaster, kept throwing CEL's with tons of codes varying from coolant temperature sensor to rich oxygen sensor, and a TPS, and some other codes that were not in my book. Any how put a new TPS on and a coolant temp sensor, ran great, had more power than ever before almost felt sporty. Still getting CEL's, so cleaned MAF bought a K&N drop in filter, drilled holes in Air box, at WOT it would totally bog down, and barley hit 65, back off a little and it would take right off, just for the heck of it I duck taped my holes in the airbox I drilled, now it does not bog near as much but still does, and still getting CEL's, So I replaced the O2 sensor, ran a little better yet still getting CEL's and bogs, also exhaust smells, and gas mileage has been terrible, under 200 miles on 19 gallons. Ran codes again and its coming back saying O2 is sensing a rich condition. I apologize about this being so long, but I'm just stumped, Oh yeah idles also erratic, sometimes idles perfect other time its at 1500 till you punch the gas then it will drop down, then other times it just lopes from about 700 to 1000rpm. I'm going out on a shear guess, but the next thing I was going to replace is the fuel regulator, does this sound like a feasible solution, or is their something else I should do??? I pulled codes tonight and I'm getting a 173 and a 179 if this helps.

 

[Alec]

Yup, could be a faulty fuel pressure regulator. I would also check to see if your throttle body and IAC are clean, and I'd also suspect that your cats are partially clogged.

 

[MrShorty]

I agree that it could be a faulty FPR. However, there are other possible causes, too. I would be inclined to stop throwing parts at it in the hopes that you will find the fix, and get it properly diagnosed. As an example, I had one that was throwing a O2 sensor rich code that turned to be a fault in the PCM. Somehow, the computer had got a crossed wire in it so that the computer was reading another voltage source in place of the O2 sensor, which caused it to think that the engine was running rich. This particular case also showed some of the same symptoms you're getting: loping idle and power loss. Factor in the exhaust smells, though, and it is likely legitimately running rich. At this point, test the fuel pressure and see if it's high. And, though high fuel pressure is likely a bad FPR, it could also be caused by a restriction in the fuel return line.
Good luck.

 

[WoodsBuggy3]

Thanks for your help, All these items I'm replacing I really don't feel too bad about cause it has 175K miles, I'm the second owner and other than preventative maintanance this truck has not been touched. I think I will go with a FPR and check return line, if that ain't it I will have a pro look at it.

 

[TPLYNCH]

Heres a link to a site with the code descriptions. http://www.troublecodes.net/Ford/eec-iv.shtml

Did not see any mention of you resetting the computer after making all your fixes/changes, especially after drilling the airbox. You need to reset the computer to clear the old codes and to let it relearn how to run with the new/modified parts.

 

[WoodsBuggy3]

Oh yeah, I've been resetting the krap out of that thing, they should come form the factory with a reset button like pc's

I'm putting on a FPR tonight, we will see. Its just acting to wierd, if it is running rich you'd think the holes in the airbox would of leaned it out a little and made it run better, but it ran way worse. I literraly got 175 miles on 17.5 gallons of fuel, and thats running it rather easy!

It really surges, you give it wot and it bogs, back off and find a sweet spot some where between 1/2 & 3/4's and it takes right off.

 

[Runnin'OnEmpty]

Woodsbuggy, dollars to doughnuts you have a bad MAF sensor. I know you cleaned it, but you seem to still be getting a bad signal from it. Maybe you could change it with a known good one, before buying one.

Also check the plug-in connector. Unplug and re-plug, and spray it with some WD-40.

 

[WoodsBuggy3]

That was like one of the 1st things I tried, I got a barley totaled 93 ranger 4 liter that I boroughrd it from and that motor runs perfect, It acted the same way.

 

[WoodsBuggy3]

well... It was a FPR, It wants to get it now

 

[TPLYNCH]

Glad you got it straightened out. The FPR's are prone to failure as they get older...