black smoke from tail pipe and rough idle

[4runneracerunner]

so ill give you guys the whole break down.

saturday i went over to my grandpas garage to do a few things with the my 1995 4runner 3.0.

i went over and changed my rear brake shoes and exhaust leak.

i knew i had a i missed fire in the cylinder one hitting and had a bad miss, because i need to replace the valave covers gasket and the head + gasket

so i did a compression check on it, it was 115. and i couldn't find a lead on were the compression is suppose to be at, so i randomly picked only cylinder witch is the 4th one, and that one was at 135, so i assume within 15 is okay.

so i put brand new sparks in them, checked them and made sure they were good, and then i start it up, there's black smoke out of the exhaust pipe, and idle less then 500 rpms.

before i checked them, it was running really good, just had a bad miss in it.

so today after work i check the wires, with a ohmes meter and they were good, pulled the plug made sure there was a spark. checked for vaccum leaks, couldn't find any besides one, and i put it back on, and then check the spark plugs in cylinders 2 and 6 and replace them, they were back as hell, and before i could get to the other two spark plugs i haven't replaced let, it was dark and i couldn't see anything. but after those 4 spark plugs i replaced, i toke it for a drive, and not as much black smoke but it was pretty bad still, and the idle raised to 500 rpms to 600 rpms they were bouncing like crazy to each other, and then after it got to running temp, it died on me when it was in park!

could it be the fuel burning in the lines? ( yes i did disconnect the wire from the distributor to the ignition coil )

low oil? bad plugs?

i mean before i touched those two spark plugs my truck ran amazing, i dont know what happen

so if you guys have any idea what i did wrong, please let me know! thank you

 

[wallytoo]

before i checked them, it was running really good, just had a bad miss in it.

how? either it had a miss, or it ran well. not both. by definition, if it "had a bad miss in it", it isn't running well.

the miss can be caused by many things. rather than wasting your money throwing parts at it, determine the cause of the problem (or problems), and solve them systematically.

 

[mikekfr]

Black smoke and rough/no idle - possibly the engine coolant temperature sensor. I had one fail in my e350 box truck and the entire engine was instant crap, missing, pouring out black smoke, over a $25 item. Replaced it ( thank U OBD 1 ) & it fired right up & was back to purring like a kitten. Good luck.