Hey guys I think i may have burnt a valve this morning. All the sudden the motor started to miss and the check engine light came on. I got the codes 25 and 26. Lean/rich condition. I just did a complete tune up. What is the best way to tell if you burnt a valve? I have not done a compression test yet, i will do that tomorrow.

 

Sounds like what happened to my '91 4Runner.
It started to miss, sputter, and the check light came on.

Did not burn a drop of oil or smoke, but ran terrible.
Are you getting a ticking noise too?

Dealer diagnosed mine, and with as many miles that were on my block, it was recommended I get a whole new motor or rebuild it.
Did not opt for that, that option cost more than the whole rig was blue booked at.

Compression in # 3 on mine was zero, so I had a totally dead cylinder too.
Also it would not pass emissions test at idle, as it was passing un-burnt gas out the tailpipe.
High RPMs were OK, but not at idel.

 

yeah a small ticking noise almost like a exhaust leak. i have a miss at idle and around 2000 rpms i feel it studder. High rpm's it runs fine. If you don't mind can i ask how much it cost you for a top end rebuild?

 

I had my compleat top end done, HG's, new valves, timing belt, water pump, all new water hoses and air line hoses, as well as 2 new injectors. My total cast was 2K to have done, Rig runs like new.

 

Ouch 2 grand. I am gonna do mine myself.

 

I did not get it done, as it was not worth it to me.
I bought a new FJ Cruiser instead

 

ummmmmmm FJ. the toyota dealership by me just got the trd one in this week. its all black with gunmetal rims and bfg all terrains. sweet!

 

So until you actually diagnose the problem, I wouldn't be setting any prices.

There are many things that will cause a misfire and lean/rich mixture codes. Ignition problems (plugs, wires, cap, rotor,etc...), Injection problems, Compression problems.

So first check the compression. If that is OK then start looking at the ignition, then move to the injection.

Find what is wrong, Then figure out how much it will cost to fix.

 

what about the #5 spark plug being cross threaded. if the plug isn't facing the right way can it cause a missfire? If i pull that plug wire off the motor doesn't ever change even when you rev it.