greg92jeepxj
Official Supporter
Recently MWR experienced a hard start/no start condition . I am reminded of a similar incident on my '92 jeep XJ 4.0 ltr. .
Prior to my hard start/no start in Dec. '04 , I was diagnosing my a/c electrical for lost current to compressor . I had carelessly spiked the PCM with a 12v test light checking a/c and aux. fan relays at PDC . I knew I had boo boo'ed because I heard the change in pitch of the idle speed after seeing and hearing negative feedback from the relay terminals which feedback to the PCM . I foolishly ignored it after I saw my jeep would restart . Should have followed through with sensor readings to verify condition of PCM. A/C electrical problem caused by a/c thermostat wiring short under dash bundled with 12 gauge wiring to blower motor resister shorted . Heavy corroded terminals at resister and blower switch caused excessive resistance and overheated wiring.
Well, that winter , I experienced the starting problem. Began diagnostics with fuel pressure check , spark , trouble codes , etc. .
Replaced battery (it died), ign. Coil (did not like reading, cracked insulation) , fuel pump and sock( did not like reading), coolant sensor (low specs) , and IAC. To no avail , I began more tests with my digital VOM but as temperatures dipped to extreme frigid digits , my meter display froze, I cried uncle and took it Chrysler. I had the feeling all along it was most likely the PCM , as with no trouble codes , that was a dead give away. With no way to check PCM, I had to do something . They determined the PCM was faulty. In my haste , I spent much money before and after dealer visit . My fault all along. It was pounded into me long before ; PROPER DIAGNOSTICS ! I knew , but did not heed . Maybe the lousy wiring repair job performed by the so call electricians(prior to my owning vehicle) to the shorted blower motor resister wiring that caused the a/c thermostat to blow every so often may have contributed , but the death blow probably was NOT using a computer-safe test light. I will never know. The moral of this story is not to rush , proper diagnostics and proper tools and procedure. Easier said than done when emotions run high and you need your daily driver NOW, but cooler heads ALWAYS prevail, even in the dead of winter ! Wish I was more careful with that test light in July ! Kudos to MWR for proper diagnostics (don't sweat the ex spence , not too bad ) and thanks to steelheadz and bounty_hunter for their support ! Wish I had you guys then , I would have probably not gone to school on that job and just got 'Er done ! Well done guys ! Glad I am a member now ! " when you've got brothers around , your a family man ! Your never alone, your never disconnected ...... " west side story . LOL
Prior to my hard start/no start in Dec. '04 , I was diagnosing my a/c electrical for lost current to compressor . I had carelessly spiked the PCM with a 12v test light checking a/c and aux. fan relays at PDC . I knew I had boo boo'ed because I heard the change in pitch of the idle speed after seeing and hearing negative feedback from the relay terminals which feedback to the PCM . I foolishly ignored it after I saw my jeep would restart . Should have followed through with sensor readings to verify condition of PCM. A/C electrical problem caused by a/c thermostat wiring short under dash bundled with 12 gauge wiring to blower motor resister shorted . Heavy corroded terminals at resister and blower switch caused excessive resistance and overheated wiring.
Well, that winter , I experienced the starting problem. Began diagnostics with fuel pressure check , spark , trouble codes , etc. .
Replaced battery (it died), ign. Coil (did not like reading, cracked insulation) , fuel pump and sock( did not like reading), coolant sensor (low specs) , and IAC. To no avail , I began more tests with my digital VOM but as temperatures dipped to extreme frigid digits , my meter display froze, I cried uncle and took it Chrysler. I had the feeling all along it was most likely the PCM , as with no trouble codes , that was a dead give away. With no way to check PCM, I had to do something . They determined the PCM was faulty. In my haste , I spent much money before and after dealer visit . My fault all along. It was pounded into me long before ; PROPER DIAGNOSTICS ! I knew , but did not heed . Maybe the lousy wiring repair job performed by the so call electricians(prior to my owning vehicle) to the shorted blower motor resister wiring that caused the a/c thermostat to blow every so often may have contributed , but the death blow probably was NOT using a computer-safe test light. I will never know. The moral of this story is not to rush , proper diagnostics and proper tools and procedure. Easier said than done when emotions run high and you need your daily driver NOW, but cooler heads ALWAYS prevail, even in the dead of winter ! Wish I was more careful with that test light in July ! Kudos to MWR for proper diagnostics (don't sweat the ex spence , not too bad ) and thanks to steelheadz and bounty_hunter for their support ! Wish I had you guys then , I would have probably not gone to school on that job and just got 'Er done ! Well done guys ! Glad I am a member now ! " when you've got brothers around , your a family man ! Your never alone, your never disconnected ...... " west side story . LOL
