Crank In Neutral Only, But No Start

[EmmJay]

'86 MJ with the 2.8 V6 and 3-spd auto. transmission.  The truck will not start OR crank in Park, and will crank and crank in Neutral but won't fire.  Any ideas as to what could cause this?

 

Recently I replaced the flexplate, which required removing and reinstalling the transmission.  After the job was done, the truck fired up right away and sounded awesome.  About three minutes later the engine cut off and smoke appeared under the hood.  Realized pretty quickly that it was electrical (the large positive starter wire had melted on the exhaust manifold, causing a short).

 

I replaced the positive battery cable but the truck still didn't start.  Replaced the starter relay--still no start.  I then tried starting it in Neutral (instead of Park) and it cranks and cranks but will not fire.  Using the screwdriver-in-the-spark-plug-wire trick, it seems as though there's no spark.

 

It sounds a little like the problem could be a bad or misaligned Neutral Safety Switch (NSS), but that would prevent the starter from energizing, wouldn't it?  And the truck started up just fine in Park after the flexplate replacement, and I haven't messed with the NSS since then.  I'm wondering if the no-spark condition is due to some other damaged caused by the short... If so, what's the most likely culprit?

[EmmJay]

Good news... Got it running today.  I ended up rechecking that all electrical connections were tight, rechecked all the fuses, then pulled a plug while a friend cranked the engine and found that, in fact, the spark was there.  I then pulled the cover off the carb, cranked it once, reinstalled the cover, cranked it again and it fired right up.

The Neutral Safety Switch was to blame for the truck not starting in Park.  When I crawled under today I found that a bracket on the driver's side of the transmission was loose.  I tightened it up and the Jeep now starts in both Park and Neutral.

[gogmorgo]

:thumbsup: