Major loss of power when flooring it

[RockcrawlerEX]

I've had this problem since I got the Explorer, just never really worked at it since it still runs really good.

But yeah, if I'll be driving at a comfortable speed, then floor it, the rpm's drop dramatically, and the truck slows as if i was pressing the brakes.

This only happens sometimes, but still worries me. Today it did it a couple times while I was trying to accelerate to pass someone.

Any ideas of what to look for?

 

[Turdle]

First I must correct a mis conception which bugs me---

Overdrive is the very tallest gear in your transmission, or, the last gear it shifts to.

When the throttle is depressed far enough, the transmission downshifts into a lower gear. Usually it is shifting out of overdrive ( 4th gear ) to 3rd gear at highway speeds.



If the engine doesn't want to rev with load, then I would check regular tuneup items such as fuel injectors-fuel pressure, spark plugs and wires, clean the maf sensor, check the air filter. If these things check good, then you might check if the cat converter is clogged. An exhaust shop should be able to check it for you.


Does the check engine light turn on? Does it turn on when you fiirst switch on the key? Does it stay lit?

 

[RockcrawlerEX]

Mmkay, my bad.
But yeah, check engine's on.
The codes that came up last time i checked (a few month's ago) were:
181 - Fuel system at Rich Adaptive Limit at part throttle (system bank 1)
186 - Injector Pulse Width Higher than expected (with BARO sensor)
189 - Same as 181, except for bank 2
332 - Insufficient EGR Flow
558 - EGR Vacuum Regulator (EVR) Circuit Failure

I changed the spark plugs a few weeks ago, fuel pressure is fine, and i cleaned the air filter when i changed the plugs. I haven't checked the fuel injectors in awhile, so I'll do that and check the cat converter, too.

 

[Turdle]

OH
Check for fuel in the vacuum line for the fuel pressure regulator. Sniff it to see if it smells gassy

 

[RockcrawlerEX]

OH
Check for fuel in the vacuum line for the fuel pressure regulator. Sniff it to see if it smells gassy

Alright, I'll do that tomorrow. Mom's using my truck so I won't have it back til later this evening.

What's wrong if it does?

 

[Iron Weasel]

Alright, I'll do that tomorrow. Mom's using my truck so I won't have it back til later this evening.

What's wrong if it does?

If there's fuel in the vacuum line going to the fuel pressure regulator, then the fuel pressure regulator itself is faulty and should be replaced.

 

[RockcrawlerEX]

If there's fuel in the vacuum line going to the fuel pressure regulator, then the fuel pressure regulator itself is faulty and should be replaced.

Alright, thank you.

 

[justin69]

mine did the same thing. it was the fuel pump. the truck sat for 5 years before I bought it. it needed a new fuel pump so I changed it. it was toast. I was too anxious on a good deal ($300) so I just threw in a new fuel pump with out cleaning the tank. I put in new gas but diddnt clean it. well.... a week and a half later it started doing what yours is doing to a T. I tried everything to fix the problem and nothing. I finally broke down and just dropped the tank again and BAM!!! that pump was so clogged up with debris I can't belive it ran when it did! it had warranty so I swapped it out and slapped in a new pump again. this time I cleaned out the tank like if it was brand spankin new. so what I'm sayin is, maybe you have some debris clogging your fuel pump

 

[Reejerey]

Sounds like a fuel delivery problem too me, which could be anything from clogged/dirty injectors to a bad fuel pressure regulator to a clogged pump pickup screen or clogged up fuel filter. Get a fuel pressure gauge and get some readings, try and rig it up so you can see it while driving at the speeds you normally have the problem

 

[RockcrawlerEX]

Oh, sorry I never updated. Turns out whatever dipshit owned the truck before I did took off the vacuum hose to the FPR and plugged it with a screw. It revs and everything fine now.

Fuel Pressure readings were:
Spec: between 35-45 psi
Actual: 40psi

Right in the middle. Didn't drop/raise when we rev'd it, either. Turned off the truck, it stayed the same.