Jcod12

i have a 97 4runner with upgraded K&N air intake and it's limited. When you hit about 45 - 70 it starts jerking real bad during accleration. The only way to keep it to a minimum is to keep rpm's high. It's been doing it without the check engine light on but the check engine light just came on. replaced the fuel filter and cleaned the maf sensors, and cleaned out the air filter. It's still a continuing problem. Any Ideas?

Elton

i would get the codes pulled

Jcod12

but do you have any sugguestions? I was kinda thinking fuel pump.

Elton

try cleaning the maf again those k&n filters just suck

Jcod12

ya i've cleaned it a few times... what do you think of putting on the old air filter?

Elton

could be the o2 sensor but it with out a code is hard to say you could pull the efi fuse for 5mins then see what happens

Jcod12

alright, i'll get the codes and check it out. thanks man. So you think fuel pump is a no go?

MTL_4runner

At this point you definately need to pull those OBD codes for us to help you further.

AaronW

here is what I would do:
1. check codes
2. clean MAF
3. check spark plugs- if you have the wrong ones- one's not specified by the owner's manual- they can cause this problem. I had the same exact problem with my car last week. Also, make sure to gap them correctly.
4. check fuel pressure to determine if fuel pump is operating correctly.
5. check your spark plug wires

I have had a high flow air filter on my '98 Limited for a few years now and haven't had any problems with it. My 2 cents.

TRDatVT

If it is only during high revs that it smooths out and during acceleration in general, I might think something along the lines of a bad knock sensor, misfire (plugs/wires) and/or O2 sensor as well. Also replace your fuel filter if that has not been done. How long since the last tune up?

leonardator

i'd say a no on the fuel pump, or the filter, they only show issues at high rpms, or that is where you notice them the most.

Jcod12

Got the codes! i got the same code as 2 problems... P0304 which came with cylinder 4 misfire. I was reading some other stuff that sugguested the tps. the stuff i was reading was on older 4runners but they had the same problem. not sure if this is any good though.

Jcod12

thanks guys, figured out the problem. The code led me straight to it. i got my oil changed a while back when the problem started. They must have bumped one of my spark plug cables because it was bouncing around loose on spark plug #4. plugged it all back together and the thing ran like new.