So my 91 4runner was running sluggish throughout all RPM's and wouldn't accelerate after about 75mph. After that happened for about a month or so, the engine finally wouldn't start up. So, I replaced the MAF sensor and it basically started right up. However, the engine still has a very low idle, under 1000rpm, and it "putts". 3rd and 4th gear aren't so bad at the higher RPM's but 1st and 2nd gear are a bit sluggish. Any help would be greatly appreciated since i'm new to toyota's. I can give more info if anyone needs it. Thanks.

 

More info on specs: last tune up? New plugs,wire,cap,air filter, fuel filter, air filter? How many miles? Have you tired using seafoam on it to blow out all the carbon build up?

 

+1 with Tofer... and a huge +1 on the seafoam..

 

the truck has about 170,000 miles on it, not sure when the last tune-up was. I can find all that out, since it's my girlfriends truck. If it hasn't been tuned up in a while, i assume i should start there? Also, what if any are bad side affects to the sea foam? I looked it up but didn't know if there were any harmful effects to the engine, rings, or anything like that. Thanks for ya'lls help.

 

my girl said that it usually gets around 240 miles to the tank, and now it's getting roughly 150miles to the tank. She said that it's sluggish and doesn't speed up when getting on the freeway and 3rd gear is the best gear to be in but obviously can't hold that too long since the rpm's are up in the higher numbers...

 

So we found out that one of the valve's is burnt up, so it's only running on 5 cylinders. Does anyone know how to do head work? we got quoted 2600 bucks! any help would be greatly appreciated.

 

btw, i'm in the phoenix area...