misfire?

99 cherokee sport automatic. I just replaced my engine with another used 4.0 and now I have a slight miss when at idle. But when I raise the idle I can still hear and feel it. I hooked the jeep up to a scan tool at work and the timming advance is jumping around a little bit. it goes like 10, 8, 11, 3, ect..when at idle, im not to sure what all that means. So far the miss is not enough to throw a code. I'm thinking it's distributor cap and or rotor related but I dont know. I doubled check to make sure all the spark plug wires are in the right firing order. Anyone have any suggestions??

Always start with tuneup stuff like plugs, wires, cap, rotor. Simple/cheap stuff first.
Another fairly common cause of a misfire is a bad fuel injector.

Not sure what to think about your timing....somebody else will chime in I'm sure.

Your right. I'm going to buy a new cap and rotor from advanced auto parts in a little bit. The plugs are in really good condition so im not in a rush to replace them. Oh and by the way does anyone know where I can buy the CCV gromets on top of the valve cover?

Don't forget a set of new wires unless the ones in yours are pretty new. If you are going to keep existing wires, at least ohm them out to ensure they are okay.

I have a 99 XJ 4cyl that kept giving me a misfire on #2. After changeing every electrical part and the injector I broke down and took it to the Stealership. they did a compression test and found that #2 was only running about 50psi compression. I switched out the head with a rebuilt one this weekend and when I inspected the old one, the #2 exhaust valve had a discentigrated edge. I think maybe it had a slight head gausket leak that was letting in air or water ????

Long story short, I would do a compression test, if you can, and maybe save a lot of money on other new stuff.

hey i need some help. my trans wont shift out of second gear. it just revvs out. It feels like the torque converter catches off and on. I am pretty sure that my trans. is in good condition and it's not an internel problem. I believe it's somethig electrical, can anyone help me? Also, my truck idles at 1700 rpm and doesn't come down. when I put it in drive it drops down to about 1100 rpm. Any help would greatly be appreciated because I need to get to work tomorrow.

TPS can mess up you tranny shiftpoints...and your idle...

Disco your TCU (transmission Control Unit) and shift your tranny mannually...

Maybe a vacuum leak? Check the vacuum hoses and make sure the bolts that connect the intake/exhaust manafold to the head are all tight.

I did a vacume test and that came up ok. Would a bad tps cause the engine to idle at 1800rpm and not come down?