1993 Jeep Cherokee Engine turns over but will not start

Tiny
JETMECH198
  • MEMBER
  • 1993 JEEP CHEROKEE
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 90,000 MILES
I have a 1993 Jeep Cherokee that will not start, I have fault codes of 12, 11, 55. I have check for spark and fuel and have niether. When I turn on the ignition I can hear the fuel pump relay kick on but then instanly turns off, but I get fuel preasure for that split second when the relay kicks on. I have read many forums and decided to change the crank shaft positon sensor, so I did and had no luck and still have the same problems. Is it possible that the pick up coil could cause no ignition and no fuel, or do you think it may be the ECM. I live in Japan and parts are hard to come by. Any troubleshooting tips would be apreciated.
Do you
have the same problem?
Yes
No
Sunday, July 20th, 2008 AT 3:38 AM

2 Replies

Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Code 11= No cranking reference signal at PCM.
Code 12= Battery disconnected in last 50 starts.
TEST NS-1A - QUALIFYING NO-START CONDITION 1. Turn ignition off. Disconnect any spark plug cable at spark plug. Insert an insulated screwdriver in spark plug cable terminal. Hold screwdriver within 1/4" of ground. 2. While cranking engine for 10 seconds, watch for spark. If a good spark occurs, go to TEST NS-2A. If a good spark does not occur, reconnect spark plug cable. Disconnect another spark plug cable at spark plug, and repeat test. 3. If a good spark occurs, go to TEST NS-2A. If a good spark does not occur, turn ignition off. Remove coil cable from distributor cap. Hold cable within 1/4" of ground. While cranking engine for 10 seconds, watch for spark. If good spark does not occur, go to next step. If good spark occurs, repair distributor cap, rotor or spark plug cables as necessary. Perform TEST VER-1. 4. Turn ignition off. Remove coil cable from coil. Using an external ohmmeter, check resistance of coil cable. If resistance is more than 15,000 ohms, replace coil cable. If resistance is less than 15,000 ohms, remove distributor cap. While cranking engine, watch distributor rotor. If distributor rotor turns, go to next step. If distributor rotor does not turn, repair distributor drive system as necessary. Perform TEST VER-1. 5. Install distributor cap and coil cable. Disconnect ignition coil connector. Inspect ignition coil connector for damaged or pushed-out terminals. Repair as necessary. Perform TEST VER-1. If ignition coil connector terminals are okay, go to next step. 6. Turn ignition on. Using DRB-II, actuate ASD fuel system. While actuating ASD fuel system, put DRB-II in voltmeter mode. Using DRB-II, check voltage on ASD relay connector output circuit(Dark Green/Orange wire on XJ and YJ bodies or Dark Green/Black wire on ZJ body). If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in Dark Green/Orange wire on XJ and YJ bodies or Dark Green/Black wire on ZJ body. Perform TEST VER-1. 7. Using DRB-II, check voltage on ASD relay connector ignition coil driver circuit (Gray wire on XJ and YJ bodies or Gray/White wire on ZJ body). If voltage is more than 10 volts, replace ignition coil. Perform TEST VER-1. If voltage is less than 10 volts, turn ignition off. Go to next step. 8. Disconnect Powertrain Control Module (PCM) connector. Using DRB-II in ohmmeter mode, check resistance at terminal No. 19 of PCM connector (Gray wire on XJ and YJ bodies or Gray/White wire on ZJ body). If resistance is more than 5 ohms, go to next step. If resistance is less than 5 ohms, repair short to ground in Gray wire on XJ and YJ bodies or Gray/White wire on ZJ body. Perform TEST VER-1. 9. Using an external ohmmeter, check resistance between ignition coil connector (Gray wire on XJ and YJ bodies or Gray/White wire on ZJ body), and PCM connector terminal No. 19. If resistance is more than 5 ohms, repair open in Gray wire on XJ and YJ bodies or Gray/White wire on ZJ body. Perform TEST VER-1. If resistance is less than 5 ohms, replace PCM. Perform TEST VER-1. CAUTION: When checking for spark, Powertrain Control Module (PCM) damage may occur if spark plug cable is held more than 1/4" away from ground. NOTE: When checking for spark, consider one or 2 sparks as a no-spark condition. Page 1 of 1 TESTS W/CODES - 2.5L & 4.0L -1993 Jeep Cherokee
Was this
answer
helpful?
Yes
No
-1
Friday, July 28th, 2017 AT 4:31 PM
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Connector identification...


https://www.2carpros.com/forum/automotive_pictures/62217_93_Cherokee_PCM_1.jpg

Was this
answer
helpful?
Yes
No
Friday, July 28th, 2017 AT 4:31 PM

Please login or register to post a reply.

Sponsored links