Bad crank or cam sensor?
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From: Northwest AR
Bad crank or cam sensor? I have narrowed down my dying engine to an intermittent problem with either one of these sensors or the wiring to them.
Both are a pain in the *** to check and are $50+ each and non returnable so I don't want to just guess and throw parts at it.
Is there a sure way to tell which is causing the issue?
At low speeds or idle the car will shut off, the tach drops unnaturally first and sometimes twitches a little at idle which has me thinking cam sensor, but I also know I had a problem with the crank sensor coming unplugged before and the tach didn't work and in the Snap On diagnostic scanner it maxed the RPM signal.
I have EFI Live so could I just scan cam hi lo and see if they fail during dying or is there something else I can monitor? EFI either doesn't record quick enough to catch the twitchy tach or something because during that the rpms stay steady on EFI live
Both are a pain in the *** to check and are $50+ each and non returnable so I don't want to just guess and throw parts at it.
Is there a sure way to tell which is causing the issue?
At low speeds or idle the car will shut off, the tach drops unnaturally first and sometimes twitches a little at idle which has me thinking cam sensor, but I also know I had a problem with the crank sensor coming unplugged before and the tach didn't work and in the Snap On diagnostic scanner it maxed the RPM signal.
I have EFI Live so could I just scan cam hi lo and see if they fail during dying or is there something else I can monitor? EFI either doesn't record quick enough to catch the twitchy tach or something because during that the rpms stay steady on EFI live
my experiance Well not having any logs and going off experiance I would go with the (ckp) crank position sensor replace alot more of those then the cmp sensor.
One reason the CMP sensor is used to determine whether a cylinder is on the firing or the exhaust stroke, and when going bad starts having some funny start ups
And the ckp is more problems with under normall driving just shuts down, and if your having any misfire codes or log your data under normall driving cause the PCM monitors the CKP sensor for momentarily drop in crankshaft speed in order to determine if a misfire is occurring. So if you seeing intermitant misfires with no codes then more like the ckp sensor.
One reason the CMP sensor is used to determine whether a cylinder is on the firing or the exhaust stroke, and when going bad starts having some funny start ups
And the ckp is more problems with under normall driving just shuts down, and if your having any misfire codes or log your data under normall driving cause the PCM monitors the CKP sensor for momentarily drop in crankshaft speed in order to determine if a misfire is occurring. So if you seeing intermitant misfires with no codes then more like the ckp sensor.
Thread Starter
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From: Northwest AR
I will check for misfires
THe funny thing is it doesn not have any issues at normal cruising speed or WOT, only at idle while the vehicle is rolling at a lot speed or sitting and usually during stops
THe funny thing is it doesn not have any issues at normal cruising speed or WOT, only at idle while the vehicle is rolling at a lot speed or sitting and usually during stops
Thread Starter
11 Second Club
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Joined: Mar 2008
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From: Northwest AR
crank sensor harness had dangled into the header tube, 2 wires burned to bare...likely rubbing each other or the headers
pulled the crank sensor and it has a small gash in the end of it, so I replaced it anyway
so far no shutting off, now even under full panic stops and hard stops while making left hand turns
pulled the crank sensor and it has a small gash in the end of it, so I replaced it anyway
so far no shutting off, now even under full panic stops and hard stops while making left hand turns
