Audiophile

Hey Guys,

1996 Jeep XJ 4L, about 200k on the speedo.

n need of a differential diagnosis here. I went to get on the freeway earlier, and started shifting through the gears, and noticed, the power drops off after 3k rpm. I also notice the check engine light came on. It wasn't running badly otherwise, idles at 800 rpm, doesn't run rough at all. I took it by a local parts place, and they tried putting the ODBC connector on it, and it wouldn't link up at all. The guy suggested checking grounds. I checked the firewall ground to the motor, and the ground on the battery (both looked fine). I also tried checking my leads on the spark plugs on both ends, and everything seemed fine.

Any ideas?

gat

What was the result of checking the leads? Ohms, please post them?
What is the fuel pressure at the rail? Sometimes the fuel pumps start to effect performance at higher speeds when they begin to fail.

Audiophile

I just meant I checked to make sure they were connected properly (not loose). My wife ran up the road to get her hair cut, as soon as she gets back, I'll check with a multi-meter.

gat

If you went to O'Reilly's, then it would likely be the same diagnostic scanner that I have. For my 1992 I need to use the cigarette lighter power adaptor (that comes with the unit) to connect to the scanner as well as connecting the odb1 connector. I'm not sure what connector that the 1996 has.

I'd be leaning towards a fuel issue. If your pressure at the rail is low, then it would be a good time to replace the pump and filter.

fb97xj1

For a 96, both. Early were OBD1, later were OBD2. The OBD1 96 may have an OBD2 port under the dash, but the OBD2 port is just a dummy that isnt connected to anything. Ive heard of atleast two that failed inspection because the station couldnt get any codes out of it. OD1 for 96 should still have the connector under the hood.

Audiophile

Thanks for the help fellas. I ran out of money changing out my wife's tires, front bearing and changing out a lower control arm. So, I'll get a fuel pressure tester this week and see if that's the problem.