Recent content by Tim_MN

If the TPS tested correctly, solve for the P1391 code. P1391 - Intermittent Loss of CMP or CKP Signal. Loss of the Cam Position Sensor or Crank Position Sensor signal has occurred. P1391 JEEP Possible Causes - Faulty Crankshaft Position Sensor (CKP) - Crankshaft Position Sensor (CKP) wire...

The 2001 JEEP Factory Service Manual has correct wire diagrams. A well crafted internet search will find one you can download. Honestly, you won't need a wire diagram, just start at the PCM and work your way to the far ends.

ECU failure is very highly unlikely. Follow the OBD-II self-diagnostic trouble codes. Suspect the TPS. Test the TPS. A Jeeper had OBD-II Check Engine Light trouble codes P0123, 0122, and 0121, Installing a new genuine Jeep TPS sensor did not solve the codes or cure the symptoms. On the...

What kinda Jeep are you working on? Year, engine, transmission, and any relevant modifications.

Acceptable test numbers now. Inspect the wire harness plugs for corrosion and bent or pushed back wire plug pins. Inspect the wire harness for melted or chafed wire insulation, or other damages. Typical problem areas are anywhere near the valve cover, or sharp casting edges.

If that TPS was in either of my XJ's it would be replaced. The TPS spec of .26 volts at minimum throttle opening (idle), to 4.5 volts at WOT wide open throttle is right out of the Factory Service Manual.

You have a low cost item that was often sold on final pages of magazines alongside the SeaMonkeys, X-ray glasses, and Ant Farms. I would suspect the 1970's electronics may have failed from age. Even if everything works perfectly the reception range is very limited. With satellite radio...

If you disconnect the TCM and shift the transmission manually 1/2, 3, OD, and if shifts promptly and correctly, the transmission is OK. TCM failure is uncommon, TPS failure is common. The TPS is the most common and most logical suspect. The Throttle Position Sensor is directly involved with...

What shocks are installed? I have RE 3.5" coils and have no complaints. I have run them locally, and in Moab, for many years. When I first installed them I also installed some Rancho shocks. Rookie mistake. The Rancho shocks seemed to be one size fits all useless, and were horrible...

Wondering why you want to swap? Is something wrong with the RE coils?

PCM failure is very highly unlikely and should only be considered after a thorough and in-depth diagnostics of the more common and more likely suspects. The CPS is the primary suspect. Test it. OBD-II sensors that are not Genuine Jeep or NTK are likely cheap Chinese clones and should be...

Long story short, you are converting a YJ long block into a 2000 XJ engine. Find a good used 0331 Cylinder head, and install all the original 2000 OBD-II engine sensors onto the YJ block. The 2000-01 ignition uses a Camshaft Pickup Sensor to fire the coil rail on the spark plugs. Just...

Put all the necessary 2000 parts onto the YJ block. Any 1987-2001 XJ Cherokee 4.0 L engine block, 1993-98 ZJ Grand Cherokee 4.0 L engine block, 1991 to 1995 YJ Wrangler 4.0 L engine block, or 1997-1999 TJ Wrangler 4.0 L engine block will interchange. Remove and re-use ( or replace with new )...

You will need to measure to determine what fits. My local drive-line shop will shorten and balance a drive shaft for $75 This Dana Spicer catalog documents driveshaft lengths for all years and drive-line variations of XJ. https://d3qx1uccksbb2n.cloudfront.net/docs/j321-cv.pdf

No communication with ECU is commonly a short circuit. Either an OBD-II 5 volts CCD Bus circuit is shorted, or 12 positive volts is shorted to the CCD. Bus. Improperly secured wire harnesses rubbing on the block or valve cover, and failed factory wire splices, or Bubba repairs are good...