Cylinder misfire assistance

[rkn4569]

So I have a problem and I'm stuck. Hoping you guys can help...

2001 4Runner with 310,000 miles.

About 3 months ago I had a cylinder start misfiring. I changed spark plugs, wires, and coil packs. A week ago it started misfiring again and the check engine code diagnosed it as a bad fuel injector on the #2 cylinder. I changed the fuel injector and spark plug. It ran fine for about 25 miles then started misfiring again. Any ideas? Could the bad fuel injector and spark plug caused damage to the wire or coil pack? I'm running blind at this point. I appreciate any help.

 

[TheDurk]

So I have a problem and I'm stuck. Hoping you guys can help...

2001 4Runner with 310,000 miles.

About 3 months ago I had a cylinder start misfiring. I changed spark plugs, wires, and coil packs. A week ago it started misfiring again and the check engine code diagnosed it as a bad fuel injector on the #2 cylinder. I changed the fuel injector and spark plug. It ran fine for about 25 miles then started misfiring again. Any ideas? Could the bad fuel injector and spark plug caused damage to the wire or coil pack? I'm running blind at this point. I appreciate any help.

OEM Denso coil packs? Even those can be defective. 1) Start by swapping coil packs with another cylinder and see if the misfire moves. 2), for peace of mind if nothing else, run a compression test. You have 310k, for Pete's sake. 3) Pull the plug and look at it. Is it fouled? Soaked in gas means no spark. Super clean means headgasket problem. Swap it out, too. I don't care if it is a week old, never chase a misfire without a brand new plug.

 

[JayRolla]

So I have a problem and I'm stuck. Hoping you guys can help...

2001 4Runner with 310,000 miles.

About 3 months ago I had a cylinder start misfiring. I changed spark plugs, wires, and coil packs. A week ago it started misfiring again and the check engine code diagnosed it as a bad fuel injector on the #2 cylinder. I changed the fuel injector and spark plug. It ran fine for about 25 miles then started misfiring again. Any ideas? Could the bad fuel injector and spark plug caused damage to the wire or coil pack? I'm running blind at this point. I appreciate any help.

This sounds like a typical issue when people buy auto parts from local part stores. Denso from Autozone is not Denso from toyota. Denso actually uses other crap companys to make there auto part store parts and just rebrand the box.

 

[LookAtThatDog]

Make sure your plug boots are in good shape