4runner Shaking in Gear

[soundmanlpte]

Hello,

I have a 98 4runner, 3.4 V6 2wd. 190k miles. I've owned since 136k.

Yesterday, it started shaking roughly while in gear and accelerating. It's like a really low rumble. It happens as soon as I shift into gear and accelerate, but stops once I get up to speed. Resumes when I get to stop light. Check engine light blinked intermittently when I was at full speed. It stops when I shift back into park. Here are a few thoughts as to what the problem may be:

- Misfire. Plugs and wires were replaced maybe 30,000 miles ago. I did not replace coil packs. Though if it were a misfire, the check engine light should remain on, correct?
- Transmission. It has been a long time since service so I think I will drain and replace fluid today.
- Drain and replace diff fluid?
- Clean IAC valve and throttle pack?

Any suggestions would be much appreciated.

Thanks!


UPDATE: I went to Advance and they told me it was reading cylinder 4 misfire.

I have changed the spark plug on cylinder 4. Ran fuel injector cleaner through the tank. Check the spark plug wires. Swapped coil packs around on the other side to see if that could be the problem, I'll know when I go back to Advance and get them to run diagnostic again. I also cleaned out the throttle body, MAF sensor, changed PCV valve, and changed the air filter.

I am down to changing the fuel injector. Any thoughts?

 

[soundmanlpte]

Changing the fuel injector today.

I guess there's no one really on this forum? I guess I need to try another.

 

[KidVermicious]

I don't know what this section is for, to be honest. Try posting in the 3rd gen section.

 

[soundmanlpte]

I don't know what this section is for, to be honest. Try posting in the 3rd gen section.

Thanks for the response. Posting there now.

 

[Kenworth]

Bad injector

 

[soundmanlpte]

Problem fixed

Turns out it was just bad wires. I inspected them visually but should have just replaced them even though they weren't old. The lesson here is ONLY use NGK plugs and wires.

And in replacing the fuel injector that did not need to be replaced. I learned this: ALWAYS special order the full o-ring and grommet replacement set. I ordered them on Amazon from Beck/Arnley. Auto parts stores only carry replacement o-ring sets from Fel-Pro. But you MUST replace the grommets as well. I pulled the injectors 3 times before I got this right. At first it was just a minor fuel fume smell. Then it was an all out leak after replacing the 2nd time. A little vaseline on the o-rings insures that they get into the fuel rail smoothly. You don't need to get a grommet set for the new injector, just for the old ones that you are re-using.

Even though it did not need to be done, I now know how to replace an injector correctly. And I replaced my intake manifold gaskets, and valve cover gaskets in the process. So I spent an extra $80 to learn how to do something right. And made myself do some necessary maintenance. You can't put a price on that.