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Hi new here and just joined, been a mechanic for 35 years.
Have a 2007 srt8 jeep I did an engine rebuild on just rings bearings and crank cut and heads redone.
will not sync crank signal and watching it on scanners it goes to 142 rpm and drops off and will sometimes flicker again but not enough to start.
sensor has 5v and ground and signal back to pcm connection does what it should with a dvm.
I do not have a scope right now and will buy one if needed, but I don't see anything wrong with crank ring and did try 2 other sensors 1 factory and same luck.
is there anything that would shut the signal off at pcm?
all grounds even per manual are good and I even used cables for some extra.
Thanks in advance, it did run before was rebuilt just spun a bearing and now im struggling.
My fear is the reluctor ring got switched somehow at machine shop. But I also do not know the sensitivity of the ring, my research shows that the cam sensor is not needed to start but the rpm signal failing is really getting me.
I do have injector pulse I also have normal spark at first start after battery unhooked for the night then upon a couple flashes the rpm signal drops and loses it.
It is hard for me to see on the boroscope video capture, are there some teeth on the reluctor wheel that looks like they have contact marks on the face of them, or is this just light reflecting on the oil?
Sorry for the delay it is just light reflecting and I will say every time I take the crank sensor out it is soaked with oil film and it has me also thinking how strong is the signal to make it thru that.
I actually got out of most the automotive and went to heavy truck I build a lot of caterpillar engines, specialize in mechanical but I said to myself this thing really slings the oil. Lol
I would start with verifying the integrity of the crank signal, with a scope. From there confirm ignition and injection pulses, again with a scope.Depending on the outcome a cam/crank relationship check may follow.
An expert is someone who knows each time more on each time less, until he finally knows absolutely everything about absolutely nothing.
I agree with Jurgen. My first move would be to scope the cam and crank shaft sensors.
The scan data rpm dropping to zero while cranking is not normal in my opinion, but without seeing the signal generated by the CKP, it's difficult to tell why that is happening.
If you don't plan on jumping into the diag game with both feet, it might be more cost effective to hire this one out to a mobile specialist than to buy a scope kit and learn how to use it for this one problem. Of course, of you do want to spend money and time to learn scope use, then this is a good place to start.
Thank you, so i searched and it seems the vantage pro would be about the best thing for me to use and play with because of the support here.
I found one local and it was 600 i offered 350 and am likely to pick it up on Tuesday.
Sadly it was a spouses that passed and she had a mechanic check it out and he said it works and is there but did not know the software off hand.
Does this sound sensible on this?
I only ask because it's not my specialty but have always learned learning it best to usually go with the most support vs best
Yes, that's a very good deal. The battery life likely will be less than great, but it's a very good tool.
There is an entire section on Scanner Danner Premium dedicated to training on that very tool, so I would say from that standpoint you are in a good position to learn while using it.
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