Engine Miss

88 XJ 4.0, was running really really rough, and I traced it back to a cracked MAP sensor Vacuum line. It helped it out a lot, but it still has a miss to it. Any suggestions? TPS/IAC/EGR/O2/CPS/Cap/Rotor/Plugs/Wires have all been replaced.

Plugs could be fouled from the MAP causing it to run so rich.

Thanks for the idea. I'll check 'em again, even though I just replaced them yesterday before I found the cracked line. Also, I'll clean the O2 as I'm sure it's loaded up with a ton of shit from running so rich.

Careful handling the O2. I wouldn't bother with cleaning it.

Did you adjust your new TPS properly?

I agree with cruiser; best to leave that oxygen sensor alone! You are apt to do more damage than good.

Also you should verify your fuel pressure is in spec. For an 88, you should have 31 psi at idle. Then disconnect the vacuum line leading to the fuel pressure regulator and the pressure should jump to approximately 39 psi.