nukinfuts29

I realize this post is long winded, and thank you in advance for sticking with it because i am at a loss.

Jeep lover from Grand Rapids, MI here! I say this incase anyone is near me and wants to drink beer and yell at my jeep with me.

First a quick background on the jeep. It is a 1993 GC 4.0 w/ 191,000mi on it. I purchased it for $200 from my brother in law. The jeep sat for around 9 months, because nobody could fix it. According to him, my wife, and her family the jeep would decide, randomly and regardless of tempature or weather, not to start. They replaced the Fue pump twice, as the mechanic said it would not come on. Long story short after some hours on this website i determined it was the security system, and handed over the cash.

The jeep ired right up when i put in a new battery at his house, and i drove it home. I then started it again, and took it into the garage where i grounded the purple/yellow wire in the door (originally i grounded in the kick panel, but this killed the tempature guage). After grounding the wire i took the glove box off and pulled out the VSS security brain.

I have not had a single issue with this jeep for the last 750 miles, until last week....

I went mudding a wek ago sunday, nohing major just some basic trails. The one puddle was quite a drop and i wacked.....well god knos what. My floors are herculinered now so i noted a tad bit of water gathering on the driver and passenger floor (possibly from under shifter...). Made it through fine, got out with it running and gave a quick visual inspection. Played around another half hour or so, and drove 20 miles to my brother in laws (go figure) where i parked and shut her down.

30 minutes later she ould not start. Fuel pump primes, engine cranks, but nadda. Pull a spark plug and check while shes being cranked, no spark. Pull the coil wire and hook in the spark plug.....no spark.

At this point the bttery dies so i say screw it, and have it towed the 45 miles to my garage where it sat until today.....

Today i go to give it a try, battery is completely dead, it wont jump or charge, so i buy a new one. New battery appears dead (no lights, no crank, nothing). So i jiggle the starter wire and wouldn't you know the dome lights all come on! Try and crank it over, and it clicks, all power going away. Jiggle the startr wire, and its back, same result.

As a bandaid i take a set of jumper caples, creating m own ground and running hot directly to the starter from the battery. She cranks over fine, no start. Remove the jumper cables and now its cranking normal, no start.

Ok so at this point in the day only the battery has been changed, and i buy a new starter cable.

Back to my original adventure, i replace the coil. Cap and rotor are maybe 6 months old, they were replaced by the brother in law. No spark still. After hours of reading, i decide to take on the evil crankshaft position sensor.

After many hours of trying to find the right combination of extensions, universals, and beer i get the new CKS in place, plug it in, and get ready to hear my jeep sing!......cranks, no start.

So i repeat the spark checking process......NOTHING. I think i may honestly be loosing my sanity.

Recap:

I have replaced the coil, battery, and CKS. I have NOT installed the new starter cable yet as it is cranking fine and i want to tackle the big issue. I do not think it is related to the security system, as i clocked several hundred miles since removing it.

I think i covered everything.

Please note i attempted to test things with my digital multimeter but it is quite clear i am completely incompetent with that tool so if you need me to test something please idiot proof it for me. I tested six crank sensors and never got a single reading and i know they were good. I hate electrical.

OverlandZJ

Check the 20 amp mini blade fuses in the power distribution center under hood.

Try swapping the ASD relay in same PDC with one having same number from another location.

If neither works..

Turn the key to the on position but not as far as the start position, let it sit. Wait for a series of clicks from the fuel pump relay and then the rush of fuel to the rail as it's powered up. Then try to start.. this will indicate the somewhat common issue of corosion in the computer, which seems more common on the 93 vintage.

nukinfuts29

Awesome information, I will try all of that first thing in the morning. Is the relay labeled as ASD on the cover? assuming for a moment that the final solution does the trick, can I swap in any computer from my series or do they have to be dealer programmed prior to going in? I know on some jeeps it matters, so for the sake of information my key is flat, gold, metal.

Thank you again for the reply!

retreaded jeeper

there is also a mounting tab for the wire harness justt rear of the distributor,this is not only a mounting tab but a ground for the computer,make sure it has good contact

nukinfuts29

Ok here is todays results:

Both 20A mini blade fuses are good. I checked them very well.

Swapped the A/C relay with the Auto shut down relay, no change.

I turned the key all the way on, but not to start, and let it stand for 7 minutes while I was under the hood listening. No clicks, no rush of fuel, no other sounds or anything.

Mounting tab for the harness behind distributor is clean and solid.

Bustedback

Replace the cam sensor in the distributor.

nukinfuts29

Would you happen to know the autozone/pepboys/etc part number? All three of our AZ's and our pepboys told me the vehicle isn't equipped with a cam sensor. Obviously it is, its even in my repair manual.

Bustedback

They call it the pick up coil.

nukinfuts29

Got it, pep boys had it for about $40 bucks. Will post back once I get it installed.

Thanks!

nukinfuts29

The manual is telling me to pull the distributor and disassmble it. I took the cap, rotor, and some retainer plate off already but I'm nervous to pull the dist as I have never dealt with timing before.....

Note that I'm 99% sure this sensor is the issue because a "magnet" was randomly stuck to the underside of the plate just above the sensor (that doesn't remove?) And when I took it out it looks very similar to the magnet attached to the new pickup coil. Ie I think the old ones broken

nukinfuts29

Can anyone confirm that I must pull the distributor? And possibly some tips before I do? I love this forum I really appreciate all the help

Bustedback

Just remove the cap and rotor, it should just pop out of there. No need to remove the distibutor.

nukinfuts29

Thanks, will get on that in the morning. I stopped once I located it to fix my wife's car. Thanks again

mtxaudiosystm

if that doesn't fix it i would take all the wires to the starter off and clean them if you haven't. i had the same problem with my 90 nissan 4x4 ended up being the ecu.

nukinfuts29

Ok just a note for future readers you do have to remove and disassemble the distributor to replace this sensor. The shaft passes through the center so it is the only way it can be done.

PROGRESS!!

I changed the cam sensor and now it starts....shoots to 1500 rpm, hangs for a second, and stalls. I repeated this about 12 times to make sure it didn't need to cycle in fuel or something. Giving it gas does nothing, actually causes it to stall quicker. No lights on dash.

Timing maybe? I used chalk and marked the position of the dist housing on the block. Then pulled it, and marked the shaft/gear/etc to make sure it reassembled the same. Rotor is in same exact spot it was when it all came apart.

I'm so close!