Knew something wasn't right, now CEL confirms.

[uefear]

I have been dealing with very poor gas mileage (160-180) a tank in my 2002 Explorer Sport with 62K miles. I knew that it wasn't right because I was getting 260 and then all of a sudden it dropped. When I crank the truck it usually starts right up but the rpms drop pretty low and then it pops them back up to the normal 750rpm range. The other day on a trip back from school I went to pass someone on the highway (going about 65) and when the truck shifted down I went nowhere but the rpms kept going up and then my check engine light started flashing. This was the first time I experienced this loss of power when trying to pass someone. Now I have this problem, I have no power after about 50mph. My friend says he thinks it could be my torque converter. Any help on the diagnosis would be appreciated. I scanned the engine for codes and it had none.

 

[KPT]

The only time I've seen the MIL flash is when the engine is missing.

I'm no expert on automatics (refuse to own one) but the no power above 50 mph might be the torque converter not locking. Do the RPM's jump if you lightly hit the brake pedal at a cruising speed?

 

[Cobraguy]

Let's not guess. Have the code read and let us know.

 

[uefear]

I did hook up the scanner and when I scanned it, it showed no codes stored. The check engine light has flashed on two different occasions, both on the highway at over 50mph but the light went back off after flashing both times.

If I am going over 50mph and I barely push the accelerator (So it does not drop a gear) then it will accelerate smooth, but slow obviously. If I push the accelerator down hard enough to make it drop a gear, that is when I have no power and the rpms will keep going up; but the truck will barely move.

In neutral the truck revs to 3,000 rpm and nothing higher, is this normal?

In drive my rpms can go above 3,000 but only if I stomp it and that is when it will drop a gear and have very sluggish and poor acceleration and misfire.

I am going to watch my rpms as I brake and see what they do, but what is normal and abnormal when it comes to braking and what your rpms should be?
EDIT: When driving up at 50 mph - 60 mph and I hit the breaks nothing changes in the rpms. If I let off the gas the rpms hover around 1k mayeb a little higher and then when i brake it still remains in the 1k range. Does this mean my converter is working fine?

Also I do have alldata, but I new to the program. Is there a way to look up the spec for the stall speed on my truck?

 

[96eb96]

I did hook up the scanner and when I scanned it, it showed no codes stored. The check engine light has flashed on two different occasions, both on the highway at over 50mph but the light went back off after flashing both times.

If I am going over 50mph and I barely push the accelerator (So it does not drop a gear) then it will accelerate smooth, but slow obviously. If I push the accelerator down hard enough to make it drop a gear, that is when I have no power and the rpms will keep going up; but the truck will barely move.

In neutral the truck revs to 3,000 rpm and nothing higher, is this normal?

In drive my rpms can go above 3,000 but only if I stomp it and that is when it will drop a gear and have very sluggish and poor acceleration and misfire.

I am going to watch my rpms as I brake and see what they do, but what is normal and abnormal when it comes to braking and what your rpms should be?
EDIT: When driving up at 50 mph - 60 mph and I hit the breaks nothing changes in the rpms. If I let off the gas the rpms hover around 1k mayeb a little higher and then when i brake it still remains in the 1k range. Does this mean my converter is working fine?

Also I do have alldata, but I new to the program. Is there a way to look up the spec for the stall speed on my truck?

blocked cats

 

[my98nnj]

Could be a transmission issue, does it feel like it's slipping?
Might be a MAF sensor too.

 

[Mr.TT]

I don't specifically know on Explorers, but usually a flashing CEL signals misfire. Your symptoms are consistent with that. I would check/replace your plugs and wires and then see if you get your idle, gas mileage, and passing performance back. You are probably retarding the heck out of your timing causing the car to fall on it's face during passing. If that doesn't fix it, O2 sensors next, esp. since your gas mileage is so bad.

 

[CAHUNTERMAN]

There are some deeper issues here if the CEL has come on but there are no codes stored. Try a different scanner or reader.

 

[Cobraguy]

There are some deeper issues here if the CEL has come on but there are no codes stored. Try a different scanner or reader.

Good point. Stored codes will go away after certain cycles are performed and no reoccurance, but that takes quite a while. I'm guessing your code reader isn't picking up the codes it should.

 

[96eb96]

What about a fuel filter? Could be a lean misfire giving the flash, hard to deliver fuel at higher speed,bad gas mileage...cheap fix, worth a shot.

 

[grkstl2]

I say check your fuel pressure. I bet your fuel pump is dying or your filter is gunked up. I just had the same issue on a conversion van, when I took the fuel PSI it confirmed it. I replaced the pump and the power and MPG is back.

 

[uefear]

Actually I just replaced the fuel filter yesterday and it didn't help but it was part of my 60k maintenance so I did it. The fuel pressure is fine...65 PSI.

Really at any speed now I cannot accelerate hard. IT feels like the engine is running on 2 cylinders when I floor it. It makes a bogged out sound and goes nowhere yet the rpms keep climbing towards 6k depending on how long I hold it down. The acceleration kinda sounds/feels like this....
waaaaaaaa.......pause......waaaaaa....pause....waaaa.paaause...waaa

waa being the noise from the engine accelerating and the pause is the part where the rpms keep goin up but i feel the truck lose power and lose forward momentum.

I did a stall test (holding the brake and gassing it for five seconds) and my rpms got to about 2300. I think this is normal although I am unable to find the stall speed for my exact 2002 explorer sport.

The truck accelerates fine if you don't push the pedal down to much. But by to much I mean barely. I drive like a grandma, never passing 2,500 rpms from a complete stop.

The thing that is really killing me here guys is that I have a 17 gallon fuel tank and I get 170 miles to the tank (10 miles to the gallon). I used to get around 260 miles (15 miles to the gallon) to a tank before something went bad.

 

[CAHUNTERMAN]

Now you are describing what sounds more like a transmission issue. If the RPM's are up there but you're not moving in the same proportion then something is going wrong in the transmission. Check the fluid level and also check the color and for a burnt smell. That might also explain why the codes don't show up. I believe transmission codes are not generic OBD codes so unless you have an enhanced scanner or reader it might not pick them up.

 

[uefear]

Tranny Fluid is in good shape. Redish color and at the proper level.

If I put the truck in 1 and drive it up to say 5,000 rpms I still get that hesitation all the way through the first gear rpm band. The Overdrive light has never blinked or done anything abnormal. The Check engine soon light aws the one that started flashing on two different occasions while accelerating to the floor on the highway. For some reason I keep wanting to point to the torque converter, but I really don't know jack sh*t about transmissions.

 

[uefear]

Now the Check Engine light is on steadily. I went to my local Advanced to get the code reader only to find that it would not communicate with my vehicle. Tried it on my friends chevy truck and it would not communicate with his either so go figure. As soon as I get the code I will report back and start researching.

 

[uefear]

Read codes there was only 1. Misfire on cylinder 5. Don't really know what to do from here. Maybe the wire and plug on cylinder 5 is not making good connection under load?

 

[Mr.TT]

Change your plugs/wires.

 

[uefear]

Do I Really need to change all of them? Or just 5? I am just wondering...

 

[Mr.TT]

How new are they? If they are brand new you can inspect #5 and see if it's not gapped right or if you have some other issue that is prematurely fouling that particular one.

If they're old then I would change them all. If one has gone out the others aren't too far behind.

 

[uefear]

I changed my plugs and wires about 6,000 miles ago (All of them). Today I am going to fiddle with cylinder 5.