1990 4Runner - chugging, missing

[jay4runner]

My 1990 4Runner has run like a clock for years. Some light 'chugging' started to occur a few weeks back - when driving along it just feels like it misses on occassion, loses power for a second. It seemed to me like it was an electrical problem of some kind (plugs, wires or something). I replaced the plugs but the problem persisted. The last 2 mornings (first thing) it has been really bad. Took to the Toyota dealer who informed me it was the plugs (that I had put the wrong ones in). I informed them that the problem existed before I replace the plugs. I asked them if it might be the wires, they didn't think so. They did what they called an idle test and said it was running fine (not sure if they actually took it for a drive). Nevertheless, I changed the plugs again to the Toyota ones. Problem still persists. What would people suggest I check for next.

 

[Rix]

head gasket is a very real possibility.

 

[jay4runner]

Turns out it was the ignition wires - replaced them this morning. Toyota didn't think it was ignition wires but I replaced them with NGK myself and it fixed the problem.

 

[Rix]

Lucky you.
NGK is the only acceptable alternative to stock, besides magnecor, IMHO.

 

[Ethanfurniss]

head gasket is a very real possibility.

Snap! What makes you think so? I have had this problem intermittently but especially in the cold weather since I changed the head 6 years ago.
My idle is rough and miss occurs in first, second and occasionally third. Mainly the rig runs fine.

 

[Rix]

Snap! What makes you think so? I have had this problem intermittently but especially in the cold weather since I changed the head 6 years ago.
My idle is rough and miss occurs in first, second and occasionally third. Mainly the rig runs fine.

its common for the head gasket to leak on that generation.