Question 2000 Tundra Random Cylinder Misfire

[dsf584]

I have had this problem for several months. My truck (2000, 2 wheel drive, v8) first started stuttering and misfiring. I changed the sparkplugs with Autolite plugs. Then changed them a second time with Autolite plugs. The engine was still misfiring.

I ran the codes - cylinders 1 and 2. So I changed those coils with cylinders 3 and 5. I waited about a month and ran the codes again. This time, cylinders 3, 4 and 6. (Should have been 3 and 5 if the coils were bad.) I put a new coil in cylinder 3 to see what would happen. After a month or so, now cylinders 3, 4, 5, and 6 all show as misfiring when running the codes.

To give you an idea about the misfiring, the truck only "stutters" sometimes. Mostly when accelerating, sometimes while just cruising, and rarely while idling. And then about half the time, not at all.

This is making absolutely no sense to me! I know the plugs aren't ngk, but they should still be alright. I have also ran fuel injector cleaner and checked the injectors which appear to be working properly. The truck has about 170,000 miles, but I am having trouble believing all the coils are failiong at once, especially since I just changed one of them. Any ideas? Thanks in advance.

[george60]

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I has a similar problem on a car -- turned out to be old worn-out spark plug wires.

George60

[Only Toyota for me]

Had that same problem on our 99 corolla. I replaced the spark plug wires, and all was good. Problem fixed.

May want to try it. They can be hard to diagnose one single wire, so i'd recomend changing them all. The plug set for the corolla was about $90 OEM.

[dsf584]

On the Tundra, there are no wires. Only individual coil packs for each cylinder. (about $70 each).