Grits4jim
NAXJA Forum User
- Location
- Knoxville, TN
I have a 97 Cherokee Sport, 4.0, manual that runs good. I had the engine overhauled in April while we were in the Phoenix area. When I got it back, it did not have nearly the same power as it did before it was rebuilt. I took it by the shop on short notice one day and they had a quick look and said for me to put some miles on it.
At the end of May I drove the Jeep to Colorado. I had to downshift a lot on hills and spent a fair amount of time in the slow lane with the 18 wheelers. I was convinced something was wrong with the engine.
Once in Colorado, I had the engine "smoked" to look for any vacuum leaks and none were found. After that we pulled the cap off the distributor and decided to move it back one tooth because the rotor was halfway between #1 and #5 post. While we were at it, we replaced the distributor because of shaft wear and oil in the bottom of it. In the new position the engine would crank but would not start. We eventually moved it back to where it was. (I've since seen a picture on this forum showing where it should be and that is where it was and is now.) While we were trying to figure out why it wasn't starting with the distributor move, we got a code about the CKP so we installed a new one. At the end of the day, the Jeep was back running just like it was at the beginning of the day with a new (reman) distributor and a CKP.
One thing I did notice that day was low manifold vacuum. Depending on whose gauge you used it was either 8" or 10" HG at idle. When I called the shop in Phoenix, they said that low vacuum was not right and asked if I could let them look at it. I drove it back to Phoenix and in less that 4 hours they had discovered the cam timing was off and had it fixed.
The engine felt strong. After my first fuel stop on the way back to Colorado, the CEL comes on. My scanner told me it was P1391 so I wiggled the wires around the distributor and erased the code. I drove the next 200 miles with no CEL. Shortly after I started from the next fuel stop, I got the CEL again.
So here I am now with the Jeep running good, with a reman distributor, a new CKP sensor and a P1391 code. I can erase the code and it will come back after the second start. I have checked the connections with a ohmmeter back to the PCM and don't find a wiring problem. I have erased the PCM memory and it didn't help.
Since there were no codes before the cam was re-timed, I'm thinking the cam position sensor may have to be moved.
Anyone have an idea of what I should try next? I'm about ready to take it to a Jeep dealer to see if they can do something,
At the end of May I drove the Jeep to Colorado. I had to downshift a lot on hills and spent a fair amount of time in the slow lane with the 18 wheelers. I was convinced something was wrong with the engine.
Once in Colorado, I had the engine "smoked" to look for any vacuum leaks and none were found. After that we pulled the cap off the distributor and decided to move it back one tooth because the rotor was halfway between #1 and #5 post. While we were at it, we replaced the distributor because of shaft wear and oil in the bottom of it. In the new position the engine would crank but would not start. We eventually moved it back to where it was. (I've since seen a picture on this forum showing where it should be and that is where it was and is now.) While we were trying to figure out why it wasn't starting with the distributor move, we got a code about the CKP so we installed a new one. At the end of the day, the Jeep was back running just like it was at the beginning of the day with a new (reman) distributor and a CKP.
One thing I did notice that day was low manifold vacuum. Depending on whose gauge you used it was either 8" or 10" HG at idle. When I called the shop in Phoenix, they said that low vacuum was not right and asked if I could let them look at it. I drove it back to Phoenix and in less that 4 hours they had discovered the cam timing was off and had it fixed.
The engine felt strong. After my first fuel stop on the way back to Colorado, the CEL comes on. My scanner told me it was P1391 so I wiggled the wires around the distributor and erased the code. I drove the next 200 miles with no CEL. Shortly after I started from the next fuel stop, I got the CEL again.
So here I am now with the Jeep running good, with a reman distributor, a new CKP sensor and a P1391 code. I can erase the code and it will come back after the second start. I have checked the connections with a ohmmeter back to the PCM and don't find a wiring problem. I have erased the PCM memory and it didn't help.
Since there were no codes before the cam was re-timed, I'm thinking the cam position sensor may have to be moved.
Anyone have an idea of what I should try next? I'm about ready to take it to a Jeep dealer to see if they can do something,