99 4Runner has no balls!

[travisimo]

So difficult to explain. It runs great 0-30mph.

But if you're going up a hill or trying to accelerate much past 40mph the engine whines and the truck just does NOT accelerate. I can get the RPM's up to about 4500 and it will just not go any faster. If i let off the gas slightly it'll shift to a lower gear

Like i said, if you're just starting out it goes perfectly fine. Only when it gets higher in the RPM's and MPH.

Things I've done currently:
Cleaned MAS
Coolant Temp Sensor
A/F Sensor
New Belts
Lucas Tune Up in a Bottle

Had a check engine light but now it's off. However still running like poop.

Any Advice would be greatly appreciated. Thanks in advance.

 

[LittleCaesar]

4runner castration is a hard thing to see. Just brutal.

In reality get a code reader and find out what the stored code(s) are. Then post them.

How old are the plugs and wires?

 

[2014 Warthog]

That sounds like a transmission problem.

You can check your ATF level and top off if necessary, possibly flush it (But you need to know what you are doing). Though it could be something actually mechanical in the trans if it only happens in some gears and not others...

 

[jeremyc74]

Could be a lot of things.

I'd start by putting a fuel pressure gauge on it and make sure that's within spec. A bad fuel pressure regulator or clogged fuel filter will do exactly what you're describing.

Vacuum issues will also cause similar issues on some vehicles, and there's also the possibility that you have a leak in the intake tract somewhere that's causing the ECU to screw up the AFR.

 

[travisimo]

Thanks a lot for the replies. In order I'm going to check the Fuel Filter/Pressure Gauge, Air Intake Leaks, The plugs/wires/ignition packs then if all else fails I'll take it to a mechanic about the tranny. I really hope it's not the trans haha.

 

[2014 Warthog]

Thanks a lot for the replies. In order I'm going to check the Fuel Filter/Pressure Gauge, Air Intake Leaks, The plugs/wires/ignition packs then if all else fails I'll take it to a mechanic about the tranny. I really hope it's not the trans haha.

The reason I brought the trans was due to the statement that you were increasing RPM but not MPH. If that is strictly the case, say at 2500 RPM you are going 40 in 3rd, then pressing the gas without down shifting it goes up to 4500 still at 40 mph, still in 3rd, then it seems likely there something slipping in the trans.

If that's not strictly the case then it's much less likely the trans.

 

[10ac]

sensor

id check that code for sure and hopefully its not what im dealing with which is the Knock sensors. when they go bad, timing is automatically retarded drastically and runs sluggish and drinks more gas than normal. possibly that or many other things. check those stored codes!!

 

[gamefreakgc]

Yeah, check the codes if you can. An auto parts store might check them for free but some stopped doing it due to legal issues about giving *advice*.

It sounds like it's just behind in maintenance with the items others have suggested. How many miles on your rig?

If you are near 200k miles or use cheap/dirty gas than a new fuel filter will be in order. There's a link in the "3rd Gen Documentation" thread to a great write up on how to do it. Just did that on mine and the only hard part is getting the old compression nuts off, the rest is easy.

 

[travisimo]

thanks again everyone for responding.

It's got 256k miles on it. It's in "good" shape. I would say it's behind on most maintenance haha. They'll still read codes. I got it read when i first acquired it but through the things I have already done, gotten it to turn off.

I did run into an interesting issue at orilieys and the kid couldn't get the computer to scan. He tried a few times then told me i might have a blown fuse. took it to advanced and it was causing him trouble but eventually got it to read.

The codes it WAS giving was P0125, P1130 and P1135. I'll go back and ask for the stored codes as well.

I've seen the link youre talking about. It's great and so is a lot of the advice on this forum. Also i gotta say, i've been on a lot of boards before and everyone is nicer to people on this board too. Love it.

 

[19963.4lsr5]

A clogged CAT will also cause your symptoms as rpm and increased air flow start backing up at the CAT.

 

[99ToyoRunner]

I'd also check to see if your cat is clogged....My dad's 07 silverado had a clogged cat and wouldn't rev past 4500k and had no power...The 3.4 isn't the fastest engine out there...But mine has plenty of power and pulls very hard when I need her too...the 5speed exploits all the power the 3.4 has to offer

 

[Bandit Runner]

I can't believe that nobody posted it yet, but you need a pair of these:

 

[1985taylor1925]

sounds like the flux capacitor is going bad

 

[Brique]

sounds like the flux capacitor is going bad

Nope, definitely the transverse clomporator. I have a couple available, but they're not cheap

 

[ILRunner98]

Might be weak piston return springs lol

 

[I-4x4]

I would check the air filter (if you haven't). I imagine a really nasty garbage filled air filter would restrict the airflow enough to drown engine performance.

 

[travisimo]

A clogged CAT will also cause your symptoms as rpm and increased air flow start backing up at the CAT.

It was absolutely a clogged CAT. I replaced the fuel filter last weekend, no luck.. Today I just took it to the ol "Quick-O Muffler" spot on the not so better part town here in Knoxville. 40 bucks later he cut out the front cat and straight pipe'd it and holy shit! Power! For the first time since I've owned this guy I finally feel like it's got some BALLS.

But for real. I've cleaned the MAS, Changed the Fuel Filter, Changed the A/F Ratio Sensor (the expensive O2 Sensor), put fuel cleaner in it and finally deleted the front cat and finally It's running right.

Suggestions on what else I need to do for maintenance? I've got new plugs i'm gonna throw in it tonight... But I want this thing running the best possible. Thanks for all the help guys.

 

[LittleCaesar]

I would change out the spark plug wires as well. For an extra $30, a set of the blue NGKs can be had from Amazon.

Make sure to get double electrode plugs for the 4runner. NGK or Denso, nothing else.

Replace the PCV with a new OEM one.

Clean the throttle body.

 

[NCrunner2012]

It was absolutely a clogged CAT. I replaced the fuel filter last weekend, no luck.. Today I just took it to the ol "Quick-O Muffler" spot on the not so better part town here in Knoxville. 40 bucks later he cut out the front cat and straight pipe'd it and holy shit! Power! For the first time since I've owned this guy I finally feel like it's got some BALLS.

But for real. I've cleaned the MAS, Changed the Fuel Filter, Changed the A/F Ratio Sensor (the expensive O2 Sensor), put fuel cleaner in it and finally deleted the front cat and finally It's running right.

Suggestions on what else I need to do for maintenance? I've got new plugs i'm gonna throw in it tonight... But I want this thing running the best possible. Thanks for all the help guys.

I should probably do this...

 

[mrtucker80]

As mentioned above, plugs and wires and as branded above, NGK or Denso. I would also suggest the wires be OEM as well, but that's just me. Air filter, oil filter, PCV valve, just a general tune-up.