So I had a huge "ah-ha!" break through with the YJ today.
Since I bought it I've been having problems with it running at mega high RPM at freeway speeds (4,000rpm@65mph) and couldn't figure it out. I get getting a code for the knock sensor so I've been dicking with that for two months and ended up replacing it, all with little effect. I was told my tach must just be off. The weird thing was, that some random days, it would run perfect and tach at about 2500 at freeway speeds and everything sounds quieter and runs better.
Anyways, today I was out with my uncle exploring a few back roads out in the mountains, and on the way home I was doing about 60mph on the highway (taching at about 2000, one of the times things are working "right.") when I realized I hadn't turned my headlights on. This is important lol.
I've always been the "see and been seen" type of driver, and I have a routine when I get in any car. I almost always turn the headlights on the same moment I start the ignition. Day or night, I always rock my headlights, and it's very, very rare for me to forget.
So there I am, 60mph, flip on my headlights, and instantly the Jeep rev's up hard and starts taching at about 3500 rpm! Wait? Wtf?
Headlights off, it kicks into OD back to 2k. Flip them on, vrrrrrrooooom 3500. Ten or 15 times I did this with the same result! WTF? Driving home I tried it again on the freeway, (it's night time at this point lol, probably looked like a crazy person) 65mph-4000rpm, flip the headlights off, 65mph 2300 rpm! Jesus H. Christ this has been my problem the whole damn time?????? :brickwall:
So I figure there is a bad ground somewhere and it's effecting the transmission computer and preventing it from kicking into OD when the headlights are on. Had I not forgotten to turn them on until I was already going highway speeds, I would have never made the connection! Thank god for being absent minded one time! At least now I can begin to fix the problem.
That is what I did to my YJ today. Anybody have any suggestions?
Cheers