So I remember there being a thread about this a while ago. But I thought I would throw in what I did to solve mine. This is a great project for the pretty spring saturdays that we should have coming soon.

1. Replaced PCV valve and did seafoam treatment though PCV vacuum line- I did this a few times.

2. Replace Spark plugs- I used NGK Laser Platinums BKR5EKPB-11 (4302)

3. New Wires and boots for the ignition coils. I think I went with NGK as well.

4. Replaced the "lifetime" fuel filter. There was some nasty stuff coming out of it. I'm soooooo thankful I did it. It was way past time to be replaced.


I had also cleaned my throttle body a few months ago, I would tag that on to this list as well if I hadn't already done it.

The truck starts easier, runs much smoother, seems to have better throttle response, and maybe a little bit better power in higher RPM (probably not starved for fuel due to dirty fuel filter). I'm hoping for a little bit better fuel economy as well.

 

Would you specifically list everything your truck was doing and when? Did you take note of which of those repairs did the most good? How were your old plugs and wires when you took them out?

 

Good info, I just got a wix filter and already planned to clean the throttle body. My engine idles fine and I'd like to keep it that way

 

Sounds like she's purrin now Miles. Hit me up some time.

 

I wasn't having many problems most of it was just and annoyance to me. After the truck was warmed up at stoplights the idle would get rough, sometimes the RPMs would actually fluctuate. Thats really the only problems I noticed. The wires where not in very bad shape, maybe starting to get a little brittle but nothing major yet. The plugs where ok they had a little white build up on them, so I think I'm going to replace my o2 sensor. I can't find any record of it having ever been replaced and the previous owner was super meticulous about service records. I had almost a file cabinet full of records of every little thing he did or had done. I never saw 02 sensor or fuel filter mentioned.

 

I have a '03 Tacoma 3.4 and just had a timing belt/water pump replaced in it. Since this has been done......the truck now has a rough idle to it that it didn't have before. Give it just about 500 RPM and it levels right out. I have replaced spark plugs, run cleaners through the fuel system and checked for bad coils.....nothing has helped. I do notice now that at higher highway speeds I can hear what sounds like a low groan from under the hood that I didn't hear before the belt change.
Is it possible that one or both of the cams pulleys is off a tooth/cog???

Any insights or experiences would be greatly appreciated.

Rick T