JakeBhs09

I drive a 99 3.4l 4runner

I recently threw a code for a misfire on cylinder 3 and had a local shop replace the coils for that cylinder along with all new plugs and wires.
Well i just noticed today after running around town for a while and was stopped in the driveway at home in park and noticed the rpms were dropping and shaking the truck. I also thought i felt some hesitation today when driving.

Any thoughts on the problem it drops for a few seconds and then returns to running smoothly.

I have not done a fuel filter change yet which i plan on, i never seem to find the time being a student. I also could use a new air filter. Would a combination
of these things be part of my problem. I hope to clean the maf and throttle body soon.



Here is a link to the video i took of the tach
http://www.youtube.com/watch?v=ZQ747hyTsAA

JakeBhs09

Bump Anybody?

Toyota Pete

I just had the same problem on my 98 4-Runner. It turned out to be a bad injector. I did the same thing with new plugs and coil, but it didn't help. When it is acting up take a long screwdiver and put the tip of it against the body of the injector and your ear against the handle, like a stethescope, you should be able to hear a click as the injector opens and closes. Compare it to another injector. If there is no click or it is very faint, that is your problem. Mine did the same thing, it would run OK sometimes and not other times. Good luck,let us know how you make out, Pete

revenantdead

i second pete here. i just had a bad injector on cyl 5

JakeBhs09

Ok well this would be my first major undertaking on doing a auto repair. I know i am very capable, I am very technically minded so i know it would be something i would enjoy learning to do. At the same time i am only 20 and have little experience? Could anyone point me in the right direction? Any write ups you know of? I searched but came up empty.

I located the fuel rails but i dont know how i would listen to the other side (with a screw driver) being they are under the intake.

Any ideas are appreciated

Ohio4R

I aslo had the same problems and it was a bad injector. Most auto parts stores will have stethescope for pretty cheap and are useful for other noises. As far as i remember youll have to take the airbox off and intake tube, cylinder 3 is the middle fuel injector.

pendrag

Seems like I hear a lot of stories like this one lately. I wonder if those 1999 injectors are all starting to go? Both of my 99s are running rough at idle, and it smoothes out at higher RPMs. I just need a day to work on them a little - been so busy lately!

shawnstcyr

Let us know the end result.

JakeBhs09

Will do, I need to do a little more research and get some money together before I attempt it. I will try and do some sort of a write up for you all.

raydouble

What kind of plugs and wires did they use?

When is the last time you cleaned your MAF sensor?

JakeBhs09

Not sure of the brand? Ill check, I have never cleaned the maf.

How do you check the injectors on cylinder 4, and 6 while it is running. If I take the intake off it won't run right.

Ohio4R

Well if you're getting a code for a misfire on cylinder 3, and youve replaced the plugs and wires my next guess would be the injector.

JakeBhs09

Well the code went away after the coils and plugs were replaced, so I dont have a code to reference now. I listened to injector 1,2,3,5 and they all were clicking.

And they all seemed to slow down when the Rpms dropped and sound about the same.

ft_surgn

When I did my injectors, I sent them to an outfit in TN who remanufactured them. put 40k on them without a lick of trouble. An affordable alternative.

JakeBhs09

Update: I started out doing a fuel filter replacement and i feel that it made a diffrence. It could be a placebo effect but it did seem to respond better. I then did a fill up and added some BG-44k it seems to be well worth the $23 it cost. As early as 1/4 to a half tank i saw improvements. After going through about a full tank the idle is much smoother and the tach does not drop as drastically as shown in the video. It does not shake much anymore either.

It is still not quite 100% though?

What is the next step?
Run more BG-44k through it again in 5k to 10k or so?

I also want to clean the MAF or IAC soon.

Hopefully this will be the end of my problems.

Beto

Don't mess with the IAC unless you have to. Speaking from experience here. Getting it remounted to the TB and working as it is supposed to can be a nightmare.

I would have said plugs, fuel filter, injector, air filter as first priorities. Seems like that's already done. Oil fresh? How about your vacuum lines? Are they all connected properly and tight, not leaking? Inspected them for cracks?

JakeBhs09

Update: It died twice at idle a few days ago. I believe it could have been some bad gas that just added to my bad idle problem. Since I filled up again it has not died yet. It also seemed to run fine at high way speed.

I cleaned the maf and it almost seems to be a little worse I hope I did not damage it. I was very careful but I did really drench it in maf cleaner.

I am going to clean off my terminals today that are kinda corroded and replace my ground strap that seems to not have good contact.

I want to also clean the throttle body and check for vacuum leaks.

What do you guys think?

JakeBhs09

It died the day after first time after I cleaned the MAF. I was just parked at idle with the air on and it died, then once at a stop light.

taco_ted

Based on my prior experience, I think you may need to take a look at the fuel injectors. I had a similar problem where my truck would run really rough, didn't seem to make much power, and the RPM's would vary at idle. However, the problem occurred intermittently, in the meantime I changed the spark plugs, wires, and ignition coils to no avail. Then it died on the road one day (fortunately just a block from where I lived), and I ended up not being able to restart it. This was due to a dead/old battery coincidentally, but when the shop looked at it, they concluded my long-term issue was a bad fuel injector and my truck has been running fine since the replacement. Using some fuel injector cleaner may help, but sometimes parts just wear out.

pendrag

My tach is doing the same thing as your vid, on both my 1999 4runners (a 2.7L and 3.4L). I'm finding that it idles bad, bogging down and shaking at stoplights, but it's better at higher RPMs. The last few days, it's started giving a little shake as I turn it off.

I need to get my injectors pulled and tested or cleaned, but it's my daily driver and I haven't had time. I'm afraid it's going to crap out on me one day if I don't get this figured out and fixed soon. All that shaking and bad idling can't be good for the truck. Please keep us posted on what's going on with your truck.