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post #16 of 50 Old 02-20-2013, 11:09 PM Thread Starter
PaYj
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1988 YJ Wrangler 
 
Join Date: Aug 2011
Location: Barnesville
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i checked for spark at the coil itself and got nothing, again i am not getting the pulse ground from the pcm to fire the ignition coil, on a side not when you are checking the red light green wire on the ckp should i be using ac or dc, i know the 5 volt wire is dc but want to make sure i am checking with right setting, i have had work last couple days so on way home today i stopped and got a analog volt meter to check the crank and cam position sensor


78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
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post #17 of 50 Old 02-21-2013, 04:23 AM
ZeeJay1997
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1997 ZJ 
 
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Meter to lowest DC scale above 5V. Black lead on battery negative
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post #18 of 50 Old 02-21-2013, 03:28 PM Thread Starter
PaYj
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ok so here are my results, on the RD/LG wire from the crank position sensor i get nothing, on the GY/BK wire from cam position sensor i get nothing, so that tells me one of two things 1 i am a idiot and forgot how to use a analog meter which is possible, or 2 both sensors are bad. I was going to check the 5v source wire for both sensors, but its to dam cold out, i need to get heat in the garage

78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
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post #19 of 50 Old 02-21-2013, 04:49 PM
ZeeJay1997
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I'm going to ask the obvious here.. were you rotating the engine when you were checking it?
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post #20 of 50 Old 02-21-2013, 05:07 PM Thread Starter
PaYj
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Location: Barnesville
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Yes

78 J10 360 V8
88 Yj 305 V8 SOA
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post #21 of 50 Old 02-21-2013, 05:56 PM
ZeeJay1997
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It's kinda hard to believe both sensors are bad especially since you were getting a reaction from the crank sensor when it was out.

You were on the right wires, Did you have your leads plugged into the correct sockets on the face of the meter.. not in amp socket? if you are sure the meter was set up corrctly and had a good reference with the negative lead, you are corrct to check the 5 volt circuit.

Here's the diagram. As you can see 5v and ground for the sensors are common to the tps, map, crank and cam sensors. The tps is easiest place to check it.
Attached Thumbnails
MAPTPSsensors.JPG   ckcmsensors.JPG  
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post #22 of 50 Old 02-21-2013, 07:16 PM Thread Starter
PaYj
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the volt meter i got only has two post, so i dont think i screwed that up, i will have to check tomorrow for the 5v source and recheck the output test again, i was in a hurry because of the weather, thank god i have others jeeps to drive to work. And thank you ZeeJay for all the help so far, its greatly appreciated

78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
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post #23 of 50 Old 02-21-2013, 07:24 PM
ZeeJay1997
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YW, yeah, it's a lot less stressful when you don't have to drive it to work the next day.
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post #24 of 50 Old 02-21-2013, 07:47 PM Thread Starter
PaYj
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Location: Barnesville
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i dont like driving the yj or j10 because of fuel, now i do like playing with them when it snows out.
Its been so long since i used a analog meter it just came to mind that i might have blown the fuse in it because i had it hooked up to the battery and i switched it to dc volts, but i passed the ohm setting on the way there,

78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
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post #25 of 50 Old 02-21-2013, 07:59 PM
ZeeJay1997
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Quote:
Originally Posted by PaYj View Post
i passed the ohm setting on the way there,
That will do it on a cheapo meter.
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post #26 of 50 Old 02-21-2013, 11:01 PM Thread Starter
PaYj
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yeah i just ran to radio crack and got one, i have a fluke digital meter but never had a use for a analog and really didnt want to spend alot of money on something i might only use once

78 J10 360 V8
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post #27 of 50 Old 02-22-2013, 12:23 PM
xrunndonex
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Ok dumb question but does it crank? Did you check cap and rotor wires plugs? if it does crank does it crank slow fast? I had this problem had to jump it well I cranked it it was flooded.

don't go towards expensive **** first. Take the spark plug wire put one hook it up to coil and plug on the other side and have someone crank it if it Sparks then you know it's cap and rotor. Do you have fuel pressure. Pressure in the cylinders.
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post #28 of 50 Old 02-23-2013, 05:38 AM Thread Starter
PaYj
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Quote:
Originally Posted by xrunndonex
Ok dumb question but does it crank? Did you check cap and rotor wires plugs? if it does crank does it crank slow fast? I had this problem had to jump it well I cranked it it was flooded.

don't go towards expensive **** first. Take the spark plug wire put one hook it up to coil and plug on the other side and have someone crank it if it Sparks then you know it's cap and rotor. Do you have fuel pressure. Pressure in the cylinders.
I understand you are stating the obvious, but the reason I posted this is because I know for a fact the coil is not getting the pulse it's supposed to fr the PCM. But to answer your question yes it cranks, the cap rotor plugs are all new, I even replaced the coil wire with a known Good one just to check for spark. So far the coil was replaced ckp whole distributor along with cam position sensor, cap rotor plugs.

Zee jay before I left for work I confirmed both sensors have the 5 volt supply, when I wake up I will check again to see if I have the pulsing 5v fr the sensors, if I do not i will check ground for the sensors, after that I am lost. I might put the old cam ps in to see if I get a 5v return from that. Is there a way to inspect the flywheel without pulling the transmission?? I never looked to see if there was a inspection cover. But I'm almost wondering if maybe the flywheel isn't damaged or something from the previous hard starting in cold weather deal

78 J10 360 V8
88 Yj 305 V8 SOA
96 Zj 3.5
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post #29 of 50 Old 02-23-2013, 06:55 AM
715raccing
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Please overlook my interrupting your conversation.
I had a similar condition and went through all of the agony you're experiencing only to find that the used computer I installed was the problem.The original quit and the replacement was defective too.
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post #30 of 50 Old 02-23-2013, 08:46 AM
ZeeJay1997
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Quote:
Originally Posted by PaYj View Post
really didnt want to spend alot of money on something i might only use once
I am fortunate to have a stack of Simpson 260s. I have had a couple of the lower quality ones and always blow fuses so dont feel like the lone ranger.

If you can turn the crankshaft slowly with a wrench and get 3 sets of 4 pulses per rotation, the flywheel is good. But if you want to look, there is an inspection cover.

If you have the sensor pulses and no ignition pulse, the PCM is the culprit. The crank and cam sensors are inputs that PCM uses to fire the coils and injectors.

BTW, all of these sensor inputs for ignition timing are on the black connector at the PCM. So at any time you can wiggle that and see if the situation with the meter changes.
Attached Thumbnails
flywheel.JPG  
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