87GN&98VET
NAXJA Forum User
- Location
- Clawson, MI
Hello all. Need some help here. I've got a 90 XJ with the 4.0L and an automatic. On a cold start, the Jeep runs very rough, backfires, and smells very rich and stalls occasionally. After 5-10 minutes when it warms up, the idle increases then settles back down, evens out and runs just fine. Warm start there are no problems. Here's what I've done:
- New coil, ignition module, wires, and plugs - all replaced about a month ago. Crank position sensor is 3 months old. All these were done to solve a no start problem. I thought I solved the problem because everything ran fine until a couple of weeks after all these were added.
- Since this seems to be temp. related, I bought a new Coolant Temp sensor, plugged it in and stuck the end into a glass of warm water (didn't want to install it if I didn't have to). No changes.
- I have a dual TPS since it is an automatic. The rectangular connector is fine, reading 5V supply and 0.8V feedback. The square connector is reading 4.67V supply, but 3.75V feedback (blue and black wires) with throttle plate closed and decreases to 0.25V at WOT. Is this normal?
- It is very cold today (in the 30s) and now it doesn't start at all. No spark from the coil to the distributor, but it is getting gas.
Am I dealing with a bad computer? Any ideas will be appreciated.
- New coil, ignition module, wires, and plugs - all replaced about a month ago. Crank position sensor is 3 months old. All these were done to solve a no start problem. I thought I solved the problem because everything ran fine until a couple of weeks after all these were added.
- Since this seems to be temp. related, I bought a new Coolant Temp sensor, plugged it in and stuck the end into a glass of warm water (didn't want to install it if I didn't have to). No changes.
- I have a dual TPS since it is an automatic. The rectangular connector is fine, reading 5V supply and 0.8V feedback. The square connector is reading 4.67V supply, but 3.75V feedback (blue and black wires) with throttle plate closed and decreases to 0.25V at WOT. Is this normal?
- It is very cold today (in the 30s) and now it doesn't start at all. No spark from the coil to the distributor, but it is getting gas.
Am I dealing with a bad computer? Any ideas will be appreciated.