My 2001 jeep wrangler tj sport start running rough with a light backfire through the tail pipe. Gradually got worse and soon much worse and stalled. When trying to restart it began backfiring through the intake. I was able to get it moving and idled it out of the highway and towed it home.
JA: How many miles are on the car? What size is the engine?
Customer: 4.0 inline 6 bored and stroked to 4.7 liter. Has run great for approximately 12000 miles
JA: Are you hoping to fix this yourself?
JA: Great! What have you tried so far?
Customer: Checked plugs, 2 of which showed proper color and 4 were dry black and sooty. Compression on cold engine was 150 psi on all but one cylinder which was 180 psi. Installed new coil rail, replaced crank position sensor and cam position sensor with Mopar part. Had battery and alternator tested. Pull some fuel from fuel rail to check for water, good fuel and pump was working. have not checked fuel pressure. Catalytic converter
was changed with new engine build but removed to check for blockage and it's not clogged.
JA: Is there anything else important you think the Jeep Mechanic should know about your Jeep?
Customer: There's a heavy gauge wire attached to the engine block where the neg batter cable is attached that has been hot enough to wrinkle the casing a couple inches up from the stud. I'd estimate the to be an 8 to 10 gauge wire. I'm wondering if this is the pcm ground wire showing signs of a short. Also when I crank the engine an get it to run for a few seconds all the lights on the instrument panel are blinking like a christmas tree, even my tach and speedo are moving which leads me to believe this to be an electrical issue. It seems like a timing issue but don't believe it's mechanical. Wondering if the computer is bad or shorted. There have been no engine codes. I can access the computer with my scanner and programmer. I've returned the computer to stock, reflashed my tune file and set it to open loop. All these processes seem to have worked fine
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Jeep Mechanic about your situation and then connect you two.