Rooztr8

Last year, I had a check engine light on my 1997 Toyota 4Runner 2.7 L.

I went to Auto Zone and got diagnostics scan and it said, "Miss Fire Cylinder 3." I purchase 4 new injectors, spark plugs, two coils packs and wire set.

I replaced all and the problems persisted. The problems has since worsened. I inspected plug 1,2 and 4 but could not remove plug 3. The other plugs looked ok. Plug 3 seems seized.

I took truck for another diagnostic scan and I got the same code, "Miss Fire Cylinder 3" .

Last year, I had to replace exhaust manifold in order to pass state safety inspection, don't know how long it was cracked.

Any Ideas????????

scuba

The 2.7's tend to have valve issues if the cracked manifold isn't replaced quickly enough or the valves aren't kept into adjustment.
The cracked manifold can let air in at the wrong moment. That mainly happens on cylinders 2 and 3 due to the common cracking of the manifold at that point. Also, a valve not adjusted can get too tight and crack the head.

I'd check compression. If that cylinder is low you'll have a lead.
If not, check valve clearances. You might get lucky and be able to simply adjust the valves back into spec.

Spray some PB blaster into the spark plug tube to hopefully loosen up that plug before trying to pull it. It could be cross threaded or simply seized. They tend to seize due to the aluminum reacting to the steel of the plug.

Good luck and let us know what you find.

Rooztr8

I feared that exact scenario. I will find a way to remove plug and check compression. Thanks Again........