93 Crank but dies, or no start

[orange]

---Long shot--
ONLY if battery is strong!

--only one time !--

-Hold foot throttle at 1/4
-turn ignition on and to start for 2-3 seconds or so.

sometimes it needs to clear to catch.

 

[hightime81]

only at 1/4 throttle? i kind of tested the range lol from idle to WOT. maybe that flooded it? it's sat for about 2 hours now, i might go give it another quick shot.

are there some electrical connections more prone to condensation than others by chance? am i missing a sensor that could be bad?

 

[hightime81]

another note, when i go to key on, my volt gauge sits at ~9 volts. i've never really noticed if that is how it was before this issue, but i thought i would make the comment.

Through reading on here, could i have flooded it enough to cause a low-compression situation? even though i haven't messed with the distributor at all, could it have jumped a tooth?

 

[joe_peters]

When you hold the pedal firmly to the floor, then start cranking, that tells the PCM to cut off the firing pulse to the injectors--its "clear flood" mode.

Plugs wet with fuel indicates the injectors are receiving a firing impulse, this could be confirmed with a $3 NOID light or a high-end ($$$$$) multimeter.

Wild shot--is the rotor turning?

 

[Ecomike]

another note, when i go to key on, my volt gauge sits at ~9 volts. i've never really noticed if that is how it was before this issue, but i thought i would make the comment.

Through reading on here, could i have flooded it enough to cause a low-compression situation? even though i haven't messed with the distributor at all, could it have jumped a tooth?

If the battery reads 13 volts at the battery, when you turn the ignition to on (not start) that is where 13 volts should be on the dash meter. If the voltage goes below that while driving, like at night with headlights on, then the alternator is toast. Beyond that it seems jeep voltage gauges are severely lacking on the calibration front.

Sounds to me like it is flooded, and it may take some effort to dry it out, especially at 29 F!!!! Try holding the gas peddle to the floor and crank it for a good 60 seconds, in maybe 6 stages at 10 seconds each. Then try it again at idle.

Pressing the gas peddle a little probably floods it faster. Better to pull a vacuum line to give it more air, and leave the gas peddle alone, at idle, if you suspect it is flooding, like maybe a stuck open injector(s)?

 

[hightime81]

i will pull the disty cap and turn it over today when i get home from work to ensure the disty is turning. however, i was getting spark, doesn't that mean that it is rotating?

as for the flooding... it's sat overnight at this point, but i will do the 'clear flood' method when i get home as well.

would a bad alternator cause a rotate but no start? like its eating up all the voltage before the engine can use it?

thanks!

 

[hightime81]

tested all the grounds as well for resistance. most i saw was 1.6 ohms. everything else was close to .08.

are there other fuses than in the fuse block in the engine bay that could be affecting this? could any of the fuses inside the cabin effect starting??

 

[hightime81]

so, still no luck at this point. the rotor spins when cranking though.

could an ignition coil test within spec but still be bad? I don't know what else could be the problem... (cleared the flood using method provided by ECOmike)

 

[Ecomike]

Check the oil to see if it is fuel of gasoline.

Last post(s) you had fuel, had spark?

That leaves a sync sensor in the dizzy I think, that controls the ECU- injector firing, but you said you found fuel on the spark plugs?

You need to check and see if the injectors are ticking while cranking!!! Use a vacuum hose as a stethoscope to listen to each injector for a tick while some one cranks. Check to see if you knocked any vac hoses loose, like MAP sensor to throttle body vac hose.

 

[hightime81]

i will double check hoses, especially near MAP since i was arms deep there!

I have fuel and spark, how do i test the sync sensor? i will listen to the injectors while cranking as well. the plugs did smell like gas when i pulled them.

i want to test the spark again tonight, farther away from a ground (3/4 inch or so) to ensure it is a good enough spark.

 

[Ecomike]

If the injectors are ticking, I think that confirms that the CPS and Sync sensors are working. 3/4" is way too much, use a spare spark plug with the proper gap.

 

[hightime81]

so i hear the injectors clicking. and by test spark, i meant strength as in hold it 3/4 inch away from ground (using a spare) to see if i still get a strong blue spark.

i went about testing the ignition coil using volts as well. with key on, testing for volts at the high voltage end of the coil, i got varying readings. from 5volts up to 12 volts. then tested while cranking and it was all over the place as well, from 8 volts to 16. does that sound right, or should it be a steady 12 volts from the coil at all times (key on, and while cranking?)

 

[hightime81]

just used the check engine light method to pull the codes but either i must be doing it wrong!

first code i get is 12, which of course isn't in my FSM as a code. (one flash, pause, two flashes)

then i get 55 which just says that it is done checking for codes.

can anyone make sense of this lol!?

 

[joe_peters]

12 = battery has been disconnected. Normal.

55 = end of codes. Normal.

Am I understanding you correctly that you are putting the common (ground, black) lead of your meter to ground, and then putting the positive (red) lead into the "big boy" coil-to-distributor contact--and only getting those low voltage readings?

Now, if you are doing that I'm surprised you haven't 1) been knocked on your butt; 2) smoked your meter.

 

[hightime81]

12 = battery has been disconnected. Normal.

55 = end of codes. Normal.

Am I understanding you correctly that you are putting the common (ground, black) lead of your meter to ground, and then putting the positive (red) lead into the "big boy" coil-to-distributor contact--and only getting those low voltage readings?

Now, if you are doing that I'm surprised you haven't 1) been knocked on your butt; 2) smoked your meter.

HAHAHAHAHHA - thats exactly what i did!

so my meter is smoked lol! at least for checking volts, however, i have rec'd FAR worse shocks when i brushed against my dryers heat element last time it broke, 220 through the wrist, now that hurt!

so did it kill my meter instantly resulting in the low voltage numbers? or is my coil toast even though the resistance was within spec?


also - testing resistance along the spark wires and they are really low, specs say to be 250-1000 per inch, i got 190 for a 6inch wire run total. i would assume that is actually better right?

 

[hightime81]

so just tried to turn it over and now the battery is low again... i will try with a jump next.

so to this point here is where i am:
1. fuses in engine bay checked and OK'd with voltmeter
2. relays switched around as well
3. crank sensor replaced even though it was within spec
4. ignition coil within resistance specs
5. all grounds refreshed and battery connections as well
6. TPS within spec
7. getting good fuel spray from schrader
8. rotor is turning and i seem to have good spark (blue snappy spark)
9. pulled and checked plugs, they are in good shape, but a little wet, still fired upon testing
10. before all of the above, had adv auto test the battery which was good.
11. fuel injectors are clicking while turning over, so that should pretty much rule out CPS and camshaft sensor (right?)
12. it will not start with starter fluid


even though it tested good, could my battery still be bad? I am not excited to spend 100$ on a new battery just to find out that isn't it. wouldn't it start with a jump even if the battery was bad???

really pulling my hair out here

what are your thoughts?

 

[hightime81]

so just tried to turn it over and now the battery is low again... i will try with a jump next... jump made it turn over faster, but it still isn't catching...

 

[joe_peters]

If those voltage numbers you posted earlier are correct, then the coil isn't putting out what it should or your meter is toasted. I don't have a voltage spec, but it should be quite hefty, as in upwards of 10,000 volts.

 

[Ecomike]

I would check the firing order and the spark plugs to make sure non of them got swapped. Also try a new primary plug wire for grins. And get the harmonic balancer turned to TDC and see where the rotor in the dizzy is pointing.

Also try a WIG! Much less painfull.

LOL

Have you tested the Air and coolant temperature sensors yet? If one of them is toast, it will keep it from starting, same with MAP sensor. I had no start except when warm to hot that nearly drove me crazy. Turned out it was the manifold air temp sensor lying to the ECU.

 

[hightime81]

haven't tested the coolant temp sensor yet, which is the air sensor? and for all of those, don't i just need to test that they are getting 5+ volts from the PCM?

and just for giggles, i did try another primary plug to no avail. i will turn it to TDC tomorrow and then see where the rotor is pointing...

So picked up a new coil just to check, didn't install it, just made the connections and let it hang and gave it a shot. turned over real slow b/c the battery is low again and didn't start. figured i should try to jump it with a good battery, got it connected and went to turn the key, heard the pump prime and said a little prayer and click, everything died. no buzzer, no lights, no nothing. It was as if the battery had been removed... jumped out the car and checked to make sure i hadn't crossed the jump cables on accident and i hadn't. removed the cables and then re-connected them and the interior light comes back on bright as day. jump in and turn the key and click, it all dies again. did this one more time before i called it for the night.

thoughts? i killed my voltmeter earlier lol, but tomorrow morning i will check the fuses with the ohm-meter to see if i blew one.