2000 3.4L 4x4 feeling sluggish...but only sometimes. no CEL

[riffman12]

2000 V6 4x4 sport. ~155k miles

So I'm a little confused here. Lately my t4r has felt really sluggish. Throttle response is fine, no CEL, but it feels like im constantly towing something.

My freeway MPG is normal: ~20-21. Hard to say, but I think it has dropped a bit around town (probably because i put my foot in it to get anywhere)

It idles great, fine when it's up to speed, just feels like something's holding it back, especially from a stop.

Weirdest part is that some days, I'll get in it, start it, and it feels great. Snappy as it used to be, smooth shifts. I'd say that's only 10% of the time now though (90% sluggish)

The transmission is shifting a little weird. Doesn't slip or anything, but the shifts occasionally kick you in the back a tad. Always done this a bit since I got it. I messed with the kickdown cable to try and help a bit.

Recent work done:
- new A/F meter (to rid of a CEL that it was throwing. CEL went away)
- New air filter in the last ~5k miles
- new plugs and wires in the last ~7k miles
- cleaned MAF ~5k miles ago
- Transmission fluid was replaced by Toyota ~20k miles ago, along with other fluids
- Driveshaft lubed less than 5k ago


I'm thinking of replacing fuel filter and running a can of Seafoam through it, but it seems like a bigger issue than just tune up issues.

Any ideas? Thanks in advance

 

[SAYWHAT]

When you cleaned the maf did you clean the two small wires that are kinda hidden in a small tube? Reason I ask is that for some reason when I cleaned mine I was only cleaning the temperature sensor which is in plain sight. Was really a dog off idle and kinda doggy on the road, no CEL. Finally opened my eyes up caught my mistake. Made a world of difference. Silly me!

 

[riffman12]

If I were a betting man I would say poor gas. Mine has always ran better in the winter but MPG will take a slight hit. The transmission will shift at high RPMs until it gets up to temp. so that always seems weird to me. It has done this since the day I bought it new and is normal. Maybe try cleaning the throttle body and MAF sensor. Then remove the negative battery terminal for around 30 minutes to an hour to reset the ECU. Might help and wont hurt.

Even on the same tank of gas, the issue will be there sometimes, and others not. So I don't think gas is the culprit.

Also, I'm familiar with the tranny holding the low gears before it's up to temp. Different issue than I'm experiencing.

Thanks for the advice. I will give the MAF and throttle body another clean and reset the ECU.

When you cleaned the maf did you clean the two small wires that are kinda hidden in a small tube? Reason I ask is that for some reason when I cleaned mine I was only cleaning the temperature sensor which is in plain sight. Was really a dog off idle and kinda doggy on the road, no CEL. Finally opened my eyes up caught my mistake. Made a world of difference. Silly me!

Yes I made sure to clean every nook and cranny of that thing. I will give it another go.


Thanks for the responses thus far. Any other ideas? Would the transmission / bad fluid / not enough fluid cause these symptoms?

 

[riffman12]

update:

it seems it may be dependent on the temperature outside. I cleaned the MAF as an easy starting point. Felt pretty good last night, but it was also cool out, so hard to say for sure.

PSA: clean your MAF.

 

[gamefreakgc]

You could have a bad ECT sensor (engine coolant temp sensor, not transmission). These little guys used to go bad on other Toyotas and not throw a code, but then again they were OBD I systems, not OBD II. But that's measuring internal coolant temperature, not outside.

The only sensor in the engine that measures and adjusts based on outside temperature is the MAF. I think you found your culprit.

 

[riffman12]

I'm hoping so.

If this doesn't fix it, I will be moving on to fuel delivery. Filter first.

 

[Rcastle]

I replaced my o2's last night and it seems to have added some pep to my 4runner. I could all be in my head though...