[Minnesota]

150000 miles. No drivability issues last two years. Now has random and intermittent ignition failure while driving.Sometimes only momentary, sometimes complete stall. No ignition for 5-10 minutes. Then hit the key and drive home. No codes on OBDII scanner. Have done two hard resets of ECM following Clymer manual. Have replaced ignition switch. Can drive 100 miles with no issue; the next trip will have 1-2 second ignition failure or complete stall. Always starts again after 5-10 minute delay. Dealerships want to throw parts at the problem. I have considered replacing the crank position sensor {170.00 OEM or 39.00 NAPA?} Local shops say abad sensor should throw a code. Key word SHOULD! Any ideas, guys?

 

[Delta0]

Have you cleaned & remade the relevant grounds yet?

What does "No ignition" mean please?

 

[snowbuggy]

I usually wait for a code before replacing a sensor. It kinda sounds heat related. I might suspect a coil but I can't remember if these are coil on plug or not.

 

[Minnesota]

Have you cleaned & remade the relevant grounds yet?

What does "No ignition" mean please?

No ignition means the engine stops, the radio display stays on.All gages go down.Sometimes this happens momentarily, like a hiccup, other times dies completely [my wife won't drive it anymore!} I have inspecte and cleaned obvious grounds in engine compartment; I'm sure I havent got them all.

 

[jtec]

stop the "reset' you dump some info, learned settings (ram) and the monitors reset to not ready...

knee jerk reaction tp your description - intermittent, restarts, no codes with scanner has me tinking CKP (cps)
With a good scanner we could check wave form of CKP, BUT to see the drop we would nave to be watchinng at the time of event
. Labor time vs sensor cost esp with the milage and no history of it being changed I would R&R -

 

[Minnesota]

stop the "reset' you dump some info, learned settings (ram) and the monitors reset to not ready...

knee jerk reaction tp your description - intermittent, restarts, no codes with scanner has me tinking CKP (cps)
With a good scanner we could check wave form of CKP, BUT to see the drop we would nave to be watchinng at the time of event
. Labor time vs sensor cost esp with the milage and no history of it being changed I would R&R -

OK; I get your point about ECM reset. FYI the onboard diagnostic shows "none" which I assume means no codes. I agree a good scanner might show something; local shops want 100.00 to scan. Since the labor is my own to replace crank sensor, do I bite the bullet {160.00 OEM} or are there decent aftermarket units available? NAPA sells their brand for about 40.00

 

[Ntrenn]

Crank sensors throw a code only about half of the time. Our most recent adventure with the wj that had similar symptoms was cured with an Oreilly crank sensor.
our Zj that had similar problems was cured with a ecm change.
crank sensor, though tedious is cheaper than ecm.

 

[Minnesota]

Crank sensors throw a code only about half of the time. Our most recent adventure with the wj that had similar symptoms was cured with an Oreilly crank sensor.
our Zj that had similar problems was cured with a ecm change.
crank sensor, though tedious is cheaper than ecm.

OK; I'm going to change the crank sensor this weekend. I'm 73 years old and have been around the block {engine and otherwise} a few times; much more comfortable fooling with my son's '69 Chevelle or my grandson's "70 Roadrunner...so SIMPLE!

 

[Delta0]

Have you considered a fault at the fuel pump yet Minn?

 

[Delta0]

No ignition means the engine stops, the radio display stays on.All gages go down.Sometimes this happens momentarily, like a hiccup, other times dies completely [my wife won't drive it anymore!} I have inspecte and cleaned obvious grounds in engine compartment; I'm sure I havent got them all.

]
Minn

 

[Ntrenn]

When you go after the crank sensor, recruit a youngun with LONG arms to reach the retaining bolt. You’ll need a wobble and about 30 inches of extensions. I did the last one myself by tying a string to the sensor pigtail and tying it off to the dipstick. 2 autojunk sensors that didn’t work before the Oreilly worked perfectly. You will want to unbolt the cross member and let it down as far as you dare. I’m only about 10 years your junior…not easy for us old dudes.
If it runs like crap at the first cranking….go get a different one. They are either crap or work perfectly. We learned…try it before you put the crossmember back up.

 

[Minnesota]

When you go after the crank sensor, recruit a youngun with LONG arms to reach the retaining bolt. You’ll need a wobble and about 30 inches of extensions. I did the last one myself by tying a string to the sensor pigtail and tying it off to the dipstick. 2 autojunk sensors that didn’t work before the Oreilly worked perfectly. You will want to unbolt the cross member and let it down as far as you dare. I’m only about 10 years your junior…not easy for us old dudes.
If it runs like crap at the first cranking….go get a different one. They are either crap or work perfectly. We learned…try it before you put the crossmember back up.

Thanks for the info; All my younguns are gone tomorrow so I'll by trying this by myself. If you jack up the drivers side slightly, I hope to get a little more clearance. I can almost get my fingers up there from the bottom. We'll see how it goes, right?

 

[Delta0]

Thanks for the info; All my younguns are gone tomorrow so I'll by trying this by myself. If you jack up the drivers side slightly, I hope to get a little more clearance. I can almost get my fingers up there from the bottom. We'll see how it goes, right?

"Jack up the driver's side slightly . . "
seems like gambling on luck

On the other hand!!

You could make yourself some wooden stands.

I made mine with a mix of 4 by 4, and 4.by 2.
The ground level ones hold the wheel about 6" off the floor

 

[Minnesota]

Replaced the crankshaft position sensor this morning. Went through the access port under the dash. Not too bad. Drove 35 miles with no issues. Fingers crossed. Thanks to all who posted. Great group

 

[Andrew D]

Hi, well done! I wasn’t even aware of the access port, good to know.


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[Ntrenn]

Access port under dash!!!! We all look dumb… glad it’s good so far.