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Unread 11-30-2011, 12:30 PM   #46
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Which pin to which pin? Went out there and couldn't read a resistance on the connector coming from the sensor.
You have to back probe the sensor while the engine is running. Use something real thin and sharp like darning needles. Yeah I don't have any either. Maybe a couple of paper clips.

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Unread 11-30-2011, 12:35 PM   #47
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You have to back probe the sensor while the engine is running. Use something real thin and sharp like darning needles. Yeah I don't have any either. Maybe a couple of paper clips.
Not even a little bit afraid to say that I don't know how to do this.

Also, I noticed that the ground strap connected to my hood is slightly frayed, however I can't see why that would be causing the trouble, since it is still all connected.
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Unread 11-30-2011, 12:35 PM   #48
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You could have a bad sensor ground from the PCM also. One circuit provides ground for the following sensors:
O2, camshaft position, intake air temp sensor, throttle position, MAP, Coolant temp and VSS sensors
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Unread 11-30-2011, 12:45 PM   #49
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Not even a little bit afraid to say that I don't know how to do this.

Also, I noticed that the ground strap connected to my hood is slightly frayed, however I can't see why that would be causing the trouble, since it is still all connected.
Take one end of a jumper cable and put it on the - battery post. Take the other end and scprare it along the radiator frame. Do you get a lot of sparks?? Then you have a bad battery ground.

Loosen the engine ground strap on both sides clean the contacts and then reinstall it. Check the battery connection also. See if that helps.

Finally if the cables have a lot of green goop inside I would replace them but first you can try this. Split open each battery cable casing for about 2" and take a peek inside. If they are all green junk them BUT FIRST remove both of them from that battery and taking one of them at a time twist each one by the battery connector vigorously several times. That breaks up the corrosion. If it works for a few days then replace both battery cables. Replace the ground strap if it is all greenish also.
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Unread 11-30-2011, 12:59 PM   #50
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All very good advice, as far as the resistance of the cps, you just need to unplug it ( just the connector not unbolt it) and put an ohmmeter on the pins (there should be only two of them) the internal resistance of the cps assy (including the wires) should be around 200 ohms. Last time I had a starting issue I found one of the wires burned from the engine it would give me very intermittent starting. I'm definitely NOT saying you should replace it, just that you should check it out.

Edit: not applicable to 92-95's
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[QUOTE=ZeroGravity;10681914]I didn't click the link because it says "power probe" in the url.[/QUOTE]
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Unread 11-30-2011, 01:59 PM   #51
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All very good advice, as far as the resistance of the cps, you just need to unplug it ( just the connector not unbolt it) and put an ohmmeter on the pins (there should be only two of them) the internal resistance of the cps assy (including the wires) should be around 200 ohms. Last time I had a starting issue I found one of the wires burned from the engine it would give me very intermittent starting. I'm definitely NOT saying you should replace it, just that you should check it out.
There's 3 pins, couldn't get a reading from any combination.
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Unread 11-30-2011, 02:23 PM   #52
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I just double checked and on a 92-95 there should be no resistance, sorry. So I guess it's good.
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Unread 11-30-2011, 02:48 PM   #53
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So I checked the grounds and battery connections. All good I can see.

Thanks for looking up that crank sensor info. Appreciate it.

Gonna keep looking tomorrow. Still can't see why pressing the pedal would help it start when it isn't getting spark. TPS signal control the spark, by chance? Doesn't explain why it starts up hot unless it sits for a couple minutes. Nothing is consistent yet it had no problems a week ago.
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Unread 11-30-2011, 05:38 PM   #54
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Spent a bunch more time researching it, doesn't seem like anything can pinpoint the issue. Going to mull through all the fuses tomorrow to see if one isn't dying and then go from there.

Starting to get a little bit frustrated and discouraged by how damn near impossible this problem is to pinpoint.
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Unread 11-30-2011, 05:42 PM   #55
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So I checked the grounds and battery connections. All good I can see.

Thanks for looking up that crank sensor info. Appreciate it.

Gonna keep looking tomorrow. Still can't see why pressing the pedal would help it start when it isn't getting spark. TPS signal control the spark, by chance? Doesn't explain why it starts up hot unless it sits for a couple minutes. Nothing is consistent yet it had no problems a week ago.
The TPS sends a voltage input of 1 volt (idle) to 4 volts (wot) signal to the PCM. That signal helps determine fuel injector pulse width and ignition timing.
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Unread 11-30-2011, 09:22 PM   #56
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The TPS sends a voltage input of 1 volt (idle) to 4 volts (wot) signal to the PCM. That signal helps determine fuel injector pulse width and ignition timing.
Thinking that if the TPS is sending faulty signals (even if it isn't throwing a code) it could be causing the no-spark issue, hence why pumping the throttle can eventually cause it to spark and run. Then again, the crank sensor could be doing the same thing. And there's still that issue of why it can start right back up within a minute but not within 5...a faulty sensor would be more consistent than that, I would think. As annoyed as I'm getting, I'm also have a boatload of fun because this is like some kind of rad puzzle...the downside is that I need groceries and can't eat until I finish the puzzle.
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Unread 11-30-2011, 11:17 PM   #57
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This really intrigues me too, I'm actually having a great time at the bar with buddies and still taking the time to figure this one out......... Can you get a hold of A buddy with a working TPS that's willing to take it off and plug it into yours to try it out?
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Unread 12-01-2011, 09:40 AM   #58
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This really intrigues me too, I'm actually having a great time at the bar with buddies and still taking the time to figure this one out......... Can you get a hold of A buddy with a working TPS that's willing to take it off and plug it into yours to try it out?
I actually told a friend of mine I would pick him up a TPS (his CEL is on for it) and install it for him, so it sort of works out that I do have a spare one as soon as I go pick it up. Gonna try that today.

edit: crap, upon looking it up - that one year makes a difference in the style. AZ says they can test them in store...gonna call and see if that's a thing I can do.

edit 2: They can't. Weak.
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Unread 12-01-2011, 10:04 AM   #59
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Have you load tested your battery?

Today's electronics are great when they work, but go haywire in low voltage conditions. When you hit the starter, your battery (and system) voltage drops to it's lowest point. If the battery is weak, you may be dropping below the critical minimum voltage for one or more sensors.

I drove my non-computer 4.2 for 1 year with a dead cell in the batt. It started OK, but a touch slow. As another cell started to fail, my cheap radio would often lose all stored stations at startup. Usually only on a cold start, not often on a hot start. I knew it was a failing battery, but thought it would just quit rather than make the electronics act up.

It is worth checking, and costs nothing if done by an auto parts store.
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Unread 12-01-2011, 10:16 AM   #60
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Have you load tested your battery?

Today's electronics are great when they work, but go haywire in low voltage conditions. When you hit the starter, your battery (and system) voltage drops to it's lowest point. If the battery is weak, you may be dropping below the critical minimum voltage for one or more sensors.

I drove my non-computer 4.2 for 1 year with a dead cell in the batt. It started OK, but a touch slow. As another cell started to fail, my cheap radio would often lose all stored stations at startup. Usually only on a cold start, not often on a hot start. I knew it was a failing battery, but thought it would just quit rather than make the electronics act up.

It is worth checking, and costs nothing if done by an auto parts store.
I could give that a try, but wouldn't the fact that I can crank it for - literally - an hour and not have it give up suggest that it is pretty decent?
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