trox

The engine runs/accelerates very rough. Theres no check engine light. scanned and found code 14 and replaced the crank sensor. replaced fuel filter, plugs and wires, air filter, O2 sensor, removed cat converter, checked MAF sensor (looks clean), what else could code 14 be?

shorod

Check for vacuum leaks. I'm not sure if the '91 4.0L was prone to intake gasket leaks or not, but they have been an issue in Explorers over the years.

-Rod

trox

thanks rod. I'll get some starter fluid and check for vacuum leaks. Is there a cam sensor on the 4.0? The guy at auto zone said if the crank sensor didn't fix it to try a cam sensor? If I don't find a cheap fix its going to cash for clunkers.

shorod

The '91 4.0L does have a camshaft position sensor if the 8th VIN digit is an 'E' and it is mounted on the left hand valve cover. If the 8th digit of the VIN is 'X' it does not have a CMP.

-Rod

trox

Just wanted to pass on what I found. So I'm shooting starter fluid all around the intake manifold looking for a vacuum leak. The next thing you know, WOOOOOF, flames all over the top of the motor. The engine wasn't that hot..yet. What the F*%# set this off? After shutting down and blowing the fire out and toasting most of the wires around thew intake, I had my kid start it back up to see if it was OK. As it was cranking I saw the back plug on the driver side arching to the block. You can guess what set it off now. I couldn't believe it but all this time it's been this damn cracked plug causing the piss poor running of the truck. It was always a backup vehicle so I never really put a lot of time into figuring it out. I just threw parts at it every once in a while. The first thing I did when it started running bad was change the plugs and wires. The plug that was cracked was one of the easiest to replace so I would have never thought of a bad plug there. Anyway, my kid was happy cuz that was gonna be his till I traded in for CASH for CLUNKERS and bought a Focus.