Howdy, I have been a lurker for a few months on this board, having bought a 97 T100 4x4 Extra Cab back in Sept of last year. Looked long and hard for what I thought was going to be a real winner......bought from original owner, who took it to the dealership for anything and everything, all the time (had endless pockets I guess). 99K but in real immaculate condition, guy used 4x4 maybe 1 or 2 times....everything seemed real good shape but I expected a few things might need replaced...also it has a nice canopy which many of the 100s in my area do not and sell for as much or more.

Anyway to make a long story short, it has been OK to me for last several months. Clutch is needing replaced, which I figured in the price. But a few days ago the CEL comes on, and starts running really rough with lots of vibration felt in the steering wheel and shifter....so much so that when I get into 4th it really shudders and I cant hardly get any speed up (like maybe 45 tops)....the sensation is like its lugging but it shouldnt be because the RPMs are up. Also it seems to be getting a little worse mileage for the last several fill ups......from like 20-21 to now about 17-18. After reading a bunch of stuff on here, I thought for sure it would be an O2 sensor

Took it into dealership today and came back as "cylinder #1 misfire more than 50% of the time" I am assuming the code# was PO301 or 302.....they checked the wires and plugs and said they were fine but I think I will check them again when I get it home.

I see in my Chilton manual that there is a lot of possibles for this problem. The dealership wants $150 to do a more indepth diagnosis, but at this point im thinking id like to try and fix it myself. Ive already given them $50 for about 15 minutes of work <img src="/forums/images/graemlins/frown.gif" alt="" />

Anyone have any suggestions or ideas?
thanks
Russ


BTW here is a pic of my truck in Redwoods NP in September

Possibly a bad coil pack on that one cylinder. If it is, don't buy an aftermarket coil pack, stick with Toyota parts.

I think the factory service manual is a great resource to have for things like this. This was the first vehicle for which I bought one and it has been well worth it.

It includes decision trees to help diagnose these type of problems.

<img src="/forums/images/graemlins/evil.gif" alt="" />

call carroll for the coil pack and tell him we sent you. you can look up his number on this board.

Question - is the misfiring cylinder one with the coil pack or the jumper wire? If the coil pack was bad would not both cylinders be misfiring? [each coil fires 2 cylinders.] You may just have a bad plug wire.

I would also check the spark plug itself - always check the obvious first!

Check at NAPA or Autozone - you may be able to bring the coil pack / plug wire in for free testing.

But make sure you replace with Toyota OEM part as already suggested.

I hate the jumper wire setup - each plug needs a coil.

I have the factory manual for that if you need some quick info. Autozone will also check the codes for you so you know what it really is if the dealer won't tell you.

Autozone does it for free? If so dang I wish I would have known that, saved me some $