Think for myself

After years of my Land Cruiser wagon, I finally moved on to the 4runner.

I just bought a 1992 a few days ago with the unreal original mileage of 120,000. It had been stored for a while and ran fine at first. Now there is a definite engine miss of some kind around 2000 rpms. Higher or lower it runs fine, but get a bit choppy in the mid range.

Now I am about to give it a tune up but I was wondering if this has happened to anyone else who could share the cause with me. It's a 4x4 V6 auto.

Thanks in advance.

myyota

Just give it a complete tune up including replacing the fuel filter, and also check all of the vacuum lines, and see if that fixes the problem.

Think for myself

Awesome.

Vacuum lines are fine. I replaced the rotor, cap, and air filter. Still working on the plugs and wires along with the fuel filter. Just learning my way around it and I must say those spark plugs are definitely in there.

The rotor was extremely worn. Already it runs much better. I expect the rest of the tune up will take care of the rest.

Thanks for the advice.

854x4

What brand spark plugs did it have. I've noticed that bosch plugs cause a miss in some toyota motors.

toyota4x4907

Use NGK or Denso plugs, wires

Think for myself

Not sure. I need one more 3/8" extension to pull them out. I am installing NGK.

Fink

Bosch plugs are crap for Toyota's - good to hear you're installing NGK's.
I'd also go ahead and run some injector cleaner through it.
Also heard miracle's about Seafoam.

Fink

854x4

Yep, using seafoam would be a good idea but I would run it through the motor using the old spark plugs. You dont want to foul the new ones out, if it knocks anything loose.

Think for myself

Right on. Thanks for the tip.

Fink

Good point, didn't even think about that.

Fink

Think for myself

Since I have same very smart folks attention, how often should I time the engine? It idles fine and runs fine at 2000+ rpms.

pb4ugotobed

Since you just bought it, I'd throw a timing light at it and make sure your base timing is set right. IIRC 10* @ 800rpm is where it should be ideally. I wouldn't try to advance it any because you're going to create more heat, which tends to do bad things to cyl #6... But don't retard it any because the 3.0 liter has kind of a hard time getting out of its own way to begin with. Great engine, don't get me wrong... It's just not in a hurry to get going, and considerably more difficult to work on than it's replacement, the 5vz. I really can't complain though, mine has 175k on it, and runs better than the wife's 05 minivan with 38k on it... and doesn't seem to burn oil like the wife's van either...