xjcrazed
NAXJA Forum User
- Location
- Draper, UT
Recently my '94 4.0 Auto XJ has been having power problems. It started suddenly, and only seems to move well at low RPM with little pedal input. With lots of pedal input, especially at high RPM, it will actually loose speed. It has also been running hot. (Just below redline unless I run the heater) A few times the check engine light has come on and I've gotten code 51 (IIRC) that indicates a lean condition. It runs and idles smooth, and starts fine, it just acts like it's extremely bogged down.
First I tried cleaning the throttle body hoping that might solve the problem. While I was doing that I noticed a radial crack around the collector in the exhaust manifold. So next I figured that too much exhaust must be escaping before the O2 sensor and therefore screwing up the signal to the computer. Since I've had headers just sitting around waiting to be put in, I decided to replace the exhaust manifold next, hence my last post about the sheared stud.
Well, I got the headers in and everything seems fine, but I still have the power loss. Could this be caused by a bad TPS or MAP/MAT sensor? Clogged cat? The only thing that seems to make sense to me right now is bad gas. Any other suggestions out there? I'm planning on draining the tank tomorrow and trying some new gas unless someone has a better idea. TIA
Rob
First I tried cleaning the throttle body hoping that might solve the problem. While I was doing that I noticed a radial crack around the collector in the exhaust manifold. So next I figured that too much exhaust must be escaping before the O2 sensor and therefore screwing up the signal to the computer. Since I've had headers just sitting around waiting to be put in, I decided to replace the exhaust manifold next, hence my last post about the sheared stud.
Well, I got the headers in and everything seems fine, but I still have the power loss. Could this be caused by a bad TPS or MAP/MAT sensor? Clogged cat? The only thing that seems to make sense to me right now is bad gas. Any other suggestions out there? I'm planning on draining the tank tomorrow and trying some new gas unless someone has a better idea. TIA
Rob