BIG Problems

[B94Sport]

I'm currently in the process of driving from PA to IL for christmas break, and my Explorer is having some pretty serious problems that are stumping me. If anyone has any ideas, please pass them along.

Here's what's going on: Suddenly I'm getting horrible gas mileage. We're talking 170 miles on a 17 gallon tank of 89 octane, all highway miles at about 75 mph.. I usually get about 280-300 miles when travelling under these circumstances.. My check engine light comes on for different periods of time that don't follow any sort of pattern, and I don't notice any performance changes when that happens. My roommate, who was driving behind me, said that whenever I press the accelerator pedal black smoke comes out my exhaust. This does not happen when I'm just driving with the cruise control on though. Only if I try to accelerate quickly. I pulled in to a gas station and opened up the hood and the whole engine seems to be rocking back and forth a lot more than it should from normal balanced operation. I tried pulling codes from it but didn't get anything. I thought I might have gotten some old gas or something, but I've filled up 3 times now and my mileage keeps getting worse! 215 the first time, 200 the second time, and 170 at the most recent gas station.

What do you guys think? Burning oil? O2 Sensors? Valves or Gaskets? Plugs? I have no idea, so if anyone can offer any sort of insight, please do. Thanks.

 

[SteveVB]

I would try and pull the codes again. The black smoke makes it a fuel problem, check for a sticking injector, and the FPR. Problem sounds like the Fuel pressure regulator- which then would cause the o2 sens. problems. But you should get codes for the o2s. I would start with the FPR, and the injectors( may be stuck open, etc).

Hope that gives you someplace to start.

 

[Rick]

I agree, it sounds like a bad fuel pressure regulator.

 

[Kris Guilbeaux]

does the engine clatter at all on Exceration. I had this same problem but the engine was clattering on exceration I could not tell you about the black smoke. But my Gas milage was not quite that bad. I got my Dealer to pull my codes and it was told to me as a bad throttle postion sensor. So, I replaced the sensor early this morning. We will see what happens.

 

[Beertime9]

I would put my money on the Throttle Position sensor, mine did the samething, but the next would be FPR, then the O2's. Good luck,

Don

 

[B94Sport]

Here's an update:

I made the last 5 hours (300 miles) of my trip today. The check engine light only came on once for about a minute, and my mileage was a little more decent: 14 mpg. Not what I usually get, but an improvement over the previous 10 mpg. There is definitely black smoke coming out of the exhaust, I ran it for a while and black liquid starts dripping out.

Now there's another symptom though: The rocking back and forth that I mentioned before returned a few times during the trip when I stopped at toll booths and the like, and it's much worse than before. When the truck is in drive and I have the brake pressed all the way, there were a few times when the entire truck would shake back and forth violently (picture an explorer on hydraulics). When I shift it into park though, it goes away. Also, while it is shaking, the battery gauge in the dash jumps back and forth between aproximately 12 and 16 volts, at the same rate as the shaking.

Anyone have any ideas? I'm taking it to the shop on Tuesday.

 

[Clint]

a little off the point but speaking of tps i took my truck to a shop before i bought a code reader to figure out why it was doing what it was doing and they said they ran a diagnostic and either my head was cracked or blown head gasket and it would cost at least a grand to fix then I asked what the pingin noise was and the "mechanic" said it was air leaking from one cyl. to the next causing a ping i laughed and went and bought a code tester and the code was for a tps i sure hate "most" mechanics

[Edited by CMartin91 on 12-23-2000 at 05:38 PM]

 

[mdrut]

been there

Had same problem. Changed O2 sensor first, then throttle positioning sensor, fixed it with the fuel pressure regulator. Call shop ahead of time, several different OEM #'s..

 

[B94Sport]

Okay, so the verdict seems to be that I need to change the O2 sensors, throttle position sensor, and fuel pressure regulator.

Now, O2 sensors I can do. But where are the other two parts located? And about how much do they cost?

 

[mdrut]

FPR

Change the fuel pressure regulator first. This will probally solve the problem. Located in the end of the fuel rail. Cost between 60 and 100 bucks depending on which one you have and where you get it. Not to difficult, couple of bolts and vaccume line. Good luck.

 

[Kris Guilbeaux]

The throttle position sensor is on the throttle body. Two screws and a elec. connection.

 

[Triton46]

Go to carparts.com, got my FPR for $40 (genuine motorcraft). Be sure to use the 33% discount.

 

[B94Sport]

On replacing the O2 sensors -
I've replace the TPS and FPR so far, and got under the truck today to replace the O2 Sensors. I can see them just fine, but I can't get the O2 sensor socket on them at all. It seems like it isn't long enough. And a regular crescent wrench isn't working. Does anyone have any helpful tips for getting the old O2s out and putting the new ones in (Including disconnecting the old O2 wires that connect somewhere up by the bell housing, and if I should remove any other parts for easier access)? Or should I just take it to the shop and have them do it? I've already worked on it for about an hour and have made no progress whatsoever.

Thanks

 

[Triton46]

I used a vice grip to grab mine at the bottom and twist off. You may have to use some WD-40 as mine was rusted to the pipe slightly.

To remove the O2 sensor make sure you take the harness off first otherwise you will twist it up as you loosen the O2 sensor. Advance Auto had the cheapest price on O2 sensors as I recall. Goodluck!

 

[mdrut]

that d#*n connector

The best I can remember, I reached thru the fender well, between the frame and the inner fender, don't remember what I used to take it off..Think it was boxed end wrench, unhooked the wires and slid them thru wrench..I think.

 

[B94Sport]

Well, after about 5 hours and as many scraped/bruised knuckles, the new O2 sensors are in. For the driver's side, I ended up just kicking the crescent wrench to get enough leverage to loosen the sensor. Then for the passenger side it just took a lot of manuevering and bending. I may have found my calling as a contortionist Once the sensors were out of the exhaust pipes it was easy to just pull them up, disconnect them, and route the new ones back down and screw them in.

Anyway.. The truck runs so much better now! Much smoother and peppier. I'm sure an improvement in gas mileage will follow, but I will have to wait a few days to see. Thanks to everyone for all the help and advice.