My Toyota runs bad and I don't know why

I am the 4th owner of this truck.I got it as a hammy down and my family members said it didn't run good when the got it and I want to fix it. The only mod to the truck is a K&N air filter that was put on and from what the previous owners said it helped. But I still can't find any problems.

 

We're gonna need more information to help you bud.
Does it idle fine? Problems starting?
First thing I would do is put the factory intake back on and clean the MAF.
More info on the MAF here.
https://www.tacomaworld.com/threads/maf-sensor-cleaning.26177/

 

Is the check engine light illuminated?? Have you scanned for codes?? Theres a heap of things that may be wrong, but as of right now, its sounding like it needs a serious freshening up. Change the engine oil, spark plugs and wires, possibly the ignition coil, PCV valve, clean your mass airflow sensor. Your fuel pump might also be on it's way out, maybe, just speculating... Fuel filter could be clogged or fuel pressure regulator could be on it's way out. Just speculating, as theres not very much specific info here to go by lol

 

We have changed all the small things like fuel filter and spark plugs and ect. The check engine light is on and it the error is to much air if I remember right and we have cleaned the MAF and replaced it before and it idles fine no problems starting there is just a real lose in power to me it Boggs down really bad when I try to accelerate and go up big hills. When I'm up in the mountains I feel like I have no power.

 

The catalytic converter might be clogged up. That is a possibility if its not making any power

 

Best thing to do is go by auto zone or just about any parts store and pull the CEL code and post it, otherwise we are just grasping at straws.

 

Yeah I was told that my family is a bunch of gear heads and we think that might be one of the problems. We are going to start with that and if not go to the fuel pump and then on from there. There is also another problem I live in such a small town there is no place to go to get codes other than my uncle who has can get them but he isn't ever really available with his job. And I work as soon as he gets of work so I won't get codes until this next week sometime

 

Let us know when you get a code, diagnosing with the help of a code could help save you some money VS just throwing parts at it.

 

Thanks for the help and I will let you guys know when I get the codes.

 

Fuel pump? It's running rich if it is getting too much air. If it isn't running rich and its getting too much air, that still doesn't lead me to think of fuel pump. It would be a MAF or IAC issue, bad 02 sensors, or something of that nature. Vacuum leak(s) as well.

It would serve you well to actually diagnose the problem(s) instead of guessing and start replacing parts that may not be anything related to what is causing the issues.

Test. Diagnose. Repair.

 

Buy a code reader, a good investment that you, and your entire family, will get much use out off.

 

To little fuel, (more air) is lean, too much fuel (less air) is rich. If it bogs down I'd think it's a fuel delivery issue. Pump, filter (which is new) or maybe a clogged injector (less likely). The cat is suspect too, as mentioned. I agree with the code, it's easy to look up and will keep you from chasing your tail.

Good luck! Keep us posted!

 

If the MAF is sensing too much air then it's adding additional fuel to to maintain 14.7:1.

No?

Not enough air would make not enough fuel and be a lean condition.

But I am tired. Could be backwards.

 

Unless the surplus of air is unmetered which would make a lean condition, and also could be a vacuum leak or dirty MAF, bad IAC, bad O2, etc.

 

wouldn't running a k&n dry with no oil make it get too much air?

just wondering

 

^^^YES^^^ Get one, they are so useful for so many things even aside from reading codes!! Ultra and scan guages are good little things to have.

 

I was at Walmart the other day. It looks like I saw I saw a code reader for about $50 or so, cheaper than a scangauge/ultra gauge

 

Over a month ago, I had to take mine in to get fixed. Ended up replacing ignition coil #4 and spark plugs. From what an auto parts store employee asked, before I brought it in to get fixed, seems like just short of a tune up. Still need to replace the air filter. Should've been done when I got the oil changed. oh well. I don't remember what the issue was.

 

Peerunner is right, a poorly functioning MAF could be misreading the amount of incoming air causing a lean/rich condition. You usually bog when too much fuel is added. At least with a carb that was true...

The amount of air coming in isn't metered by the engine so much as monitored by the MAF. The intake does however have restrictions like air filter, throttle body diameter ect. The MAF senses available incoming oxygen and adjusts fuel levels to accommodate. As a filter gets progressively more restrictive as it gets dirty, the MAF takes notice and ECU will cut fuel to maintain the optimum AF ratio. Less air coming in means less fuel from the ECU, thus decreasing power will be noticed. You can never have too much oxygen coming in or going out. You just need the correct amount of fuel to make power. The O2 sensors monitor exhaust gases and also helps the ECU adjust the AF ratio for a cleaner burn. Why two O2 sensors? My guess is to help monitor the effectiveness of the catalytic converter. If you have a restriction in the amount of fuel you can deliver you may run lean as you just won't have enough fuel available to make power. Also, by running too lean (especially in the old days of carbs) the engine runs hotter.

That said I got a Scan Gauge II a while back and I love it. I've never thrown a code but with 150k mi on the clock I'm sure it will just be a matter of time.

 

Nope. You can run no filter whatsoever, the engine can only take in so much air per stroke. The only thing a filter change/no filter/dirty can do is make it easier/harder to pull that air. Until you go forced induction anyway.