What could be the problem?

[photodude]

Ok, So I have searched all over the internet with no avail so I'm going to ask the experts here and see what the problem may be. I have a 2001 Toyota 4Runner SR5 4WD with a nagging stuttering problem. I changed all the plugs since the code came up with plug #4 misfire, had all the coil packs replaced, MAF cleaned and then replaced and still have the same problem. When I am at an intersection or whatever....dead stop, once I start to accelerate the truck stutters when I am in Drive, however if I start from a dead stop with the truck in low and then manually shift it to second, then to drive it runs fine. Truck Idles fine with no problem it's just when I'm driving. Anyone out there have the same problem or know of anyone that has??? I would greatly appreciate any help as this is getting annoying as you can imagine. Thanks

 

[photodude]

One other thing...is their a module or sensor that could be bad that tells the transmission when to shift?

 

[toytech76]

What did the plug look like on #4? Did it have any carbon tracks down the side at all? Injectors are also known to fail. There are several things that will give you a misfire.

If he has a misfire code, it wouldnt be because of a trans problem

 

[photodude]

Plugs looked great when I pulled them out. No dark spots or streaks at all. Just doesn't make sense that it runs fine if I shift it manually, but if I leave it in drive it sputters. I haven't done the injectors yet, just because of the fact it runs fine when shifting manually and the fact that it idles fine.

 

[toytech76]

Dont just throw parts at it hoping it fixes it. If you know anyone with any diagnostic tools or anything, try to see if you can pinpoint it. Kind of sounds like an electrical miss. Sometimes you can have a smooth idle and it seems to run ok, but when you put any kind of load on it like when driving, it creates a miss. You may have a wire thats arcing inside the plug tube. When the injectors go bad, they can sometimes cause a sporatic miss, not making any sense as to when they fail and act normally

 

[photodude]

I will ask the few that I know if they have any of the diagnostic tools available to them. I thank you for your replies as any help is greatly appreciated. I will post the fix if and when I get it.

 

[pat161]

You said you replaced plugs and coil packs, did you also replace the 3 wires while you were in there? The 3.4 only uses 3 coil packs, so there are still 3 wires connecting the opposite bank of plugs to your 3 coil packs.

 

[photodude]

At this point I have not, only because the local parts store didn't have them in stock. I am planning on doing that this weekend though even if I have to drive to the next town over to pick them up.

 

[toytech76]

Do yourself a favor if you replace your wires. Only use factory wires and any tune up parts. You will be much better off in the long run

 

[photodude]

So taking the advice from you guys, I called up the local Toyota dealership and picked up a set of wires and swapped them out. And low and behold...the problem & check engine light went away. I am so happy...Thanks again everyone.