ScootRider1960
06-02-2014, 10:02 AM
I have a '99 with the 4.0. I put a new long block in it about 30,000 ago. Until recently it has run great.
Now, it starts right up and runs smooth when cold, after about 1 minute it starts running rough and backfiring through the intake. Then after about another minute it smooths back out and runs fine until I shut it down and it cools off again. I replaced plugs, wires, cap, rotor, air filter and it still does it.
Any ideas?????
Now, it starts right up and runs smooth when cold, after about 1 minute it starts running rough and backfiring through the intake. Then after about another minute it smooths back out and runs fine until I shut it down and it cools off again. I replaced plugs, wires, cap, rotor, air filter and it still does it.
Any ideas?????