Loosing Crank Signal
I'm just going by some youtube videos like this one pasted below, which was a magnetised cam shaft. Bernie shows several videos in his channel with magnetized shafts, but says he usually just replaces the part. If just the reluctor wheel he's used handheld degaussers with success as well. This is very rare and probably NOT the OPs problem. But you never know.
There was another video of his where he takes the part to an airport where they have some equipment like giant degaussers and can demagnetize large engine parts apparently for super expensive shafts. Very fun channel to watch. Aha moment for this example I think was like 7:00 into the video. EDIT: the YouTuibe link is erroring for me so here's another link https://vid.puffyan.us/watch?v=SCqPkceWL9o or search for "2008 Subaru Legacy CMP failing" by Automotive Test Solutions.
Last edited by mk3cn4; Sep 10, 2023 at 12:24 PM.
Teching In
Joined: Aug 2023
Posts: 16
Likes: 11
From: PA
Yes I figured mine out! Was completely ground related! I believe most of the others that had the issue will also be ground related, unless you had the crank out of the block, and/or replaced it, but mine was original, low mile unit..
When I relocated the battery to the rear of the truck and rerouted the cables I used bulkhead fittings and my ground wasn't secured properly to the block directly from the battery (grounds need to be tight, and crimps need to be perfect! Not to the head, but the block) Also added grounds from that bulkhead junction to the chassis, and body, and in the back from the battery neg directly to the body also so the dirty grounds can use the body/chassis like a buss bar, and do not interfere with the direct ground from battery to the block!(not the head like I had before) since there are already grounds designated from the coils to the heads, you need to make sure to go directly to clean block surface..
I could definitely see these grounding issues leading to magnetism of the reluctor also, as stated by others..
hope you solve yours! Just start grabbing grounds and pulling on them to see if anything is loose first!
When I relocated the battery to the rear of the truck and rerouted the cables I used bulkhead fittings and my ground wasn't secured properly to the block directly from the battery (grounds need to be tight, and crimps need to be perfect! Not to the head, but the block) Also added grounds from that bulkhead junction to the chassis, and body, and in the back from the battery neg directly to the body also so the dirty grounds can use the body/chassis like a buss bar, and do not interfere with the direct ground from battery to the block!(not the head like I had before) since there are already grounds designated from the coils to the heads, you need to make sure to go directly to clean block surface..
I could definitely see these grounding issues leading to magnetism of the reluctor also, as stated by others..
hope you solve yours! Just start grabbing grounds and pulling on them to see if anything is loose first!
TECH Fanatic
Joined: Jan 2009
Posts: 1,065
Likes: 476
From: Bostwick, GA.
In the FWIW dept:
"(grounds need to be tight, and crimps need to be perfect"...
We use a 2-step method when making up a heavy power or ground cable.
A small hole is drilled behind the loop into the cable cavity.
The crimp is made with a real cable crimper, not a beat it tight deal.
Once crimped, the device is heated up and solder is fed into the hole.
Then a color-coded shrink sleeve with adhesive in it, is put on.
"(grounds need to be tight, and crimps need to be perfect"...
We use a 2-step method when making up a heavy power or ground cable.
A small hole is drilled behind the loop into the cable cavity.
The crimp is made with a real cable crimper, not a beat it tight deal.
Once crimped, the device is heated up and solder is fed into the hole.
Then a color-coded shrink sleeve with adhesive in it, is put on.
TECH Senior Member
Joined: Jun 2016
Posts: 22,298
Likes: 3,619
From: Central Cal.
In the FWIW dept:
"(grounds need to be tight, and crimps need to be perfect"...
We use a 2-step method when making up a heavy power or ground cable.
A small hole is drilled behind the loop into the cable cavity.
The crimp is made with a real cable crimper, not a beat it tight deal.
Once crimped, the device is heated up and solder is fed into the hole.
Then a color-coded shrink sleeve with adhesive in it, is put on.
"(grounds need to be tight, and crimps need to be perfect"...
We use a 2-step method when making up a heavy power or ground cable.
A small hole is drilled behind the loop into the cable cavity.
The crimp is made with a real cable crimper, not a beat it tight deal.
Once crimped, the device is heated up and solder is fed into the hole.
Then a color-coded shrink sleeve with adhesive in it, is put on.
Teching In
Joined: Aug 2023
Posts: 16
Likes: 11
From: PA
In the FWIW dept:
"(grounds need to be tight, and crimps need to be perfect"...
We use a 2-step method when making up a heavy power or ground cable.
A small hole is drilled behind the loop into the cable cavity.
The crimp is made with a real cable crimper, not a beat it tight deal.
Once crimped, the device is heated up and solder is fed into the hole.
Then a color-coded shrink sleeve with adhesive in it, is put on.
"(grounds need to be tight, and crimps need to be perfect"...
We use a 2-step method when making up a heavy power or ground cable.
A small hole is drilled behind the loop into the cable cavity.
The crimp is made with a real cable crimper, not a beat it tight deal.
Once crimped, the device is heated up and solder is fed into the hole.
Then a color-coded shrink sleeve with adhesive in it, is put on.
Me too! Thankyou for the insight! I've been heatshrinking them with the adhesive type, but this is my first boosted ls with standalone, and am just learning how to properly wire a racecar.. I have 20 years of general wiring experience, but Im learning there are a good amount of procedures that really can screw up an install fast if not followed to the T!
take care
8 Second Club
Joined: Apr 2006
Posts: 1,011
Likes: 31
From: in my neighborhood
Yes I figured mine out! Was completely ground related! I believe most of the others that had the issue will also be ground related, unless you had the crank out of the block, and/or replaced it, but mine was original, low mile unit..
When I relocated the battery to the rear of the truck and rerouted the cables I used bulkhead fittings and my ground wasn't secured properly to the block directly from the battery (grounds need to be tight, and crimps need to be perfect! Not to the head, but the block) Also added grounds from that bulkhead junction to the chassis, and body, and in the back from the battery neg directly to the body also so the dirty grounds can use the body/chassis like a buss bar, and do not interfere with the direct ground from battery to the block!(not the head like I had before) since there are already grounds designated from the coils to the heads, you need to make sure to go directly to clean block surface..
I could definitely see these grounding issues leading to magnetism of the reluctor also, as stated by others..
hope you solve yours! Just start grabbing grounds and pulling on them to see if anything is loose first!
When I relocated the battery to the rear of the truck and rerouted the cables I used bulkhead fittings and my ground wasn't secured properly to the block directly from the battery (grounds need to be tight, and crimps need to be perfect! Not to the head, but the block) Also added grounds from that bulkhead junction to the chassis, and body, and in the back from the battery neg directly to the body also so the dirty grounds can use the body/chassis like a buss bar, and do not interfere with the direct ground from battery to the block!(not the head like I had before) since there are already grounds designated from the coils to the heads, you need to make sure to go directly to clean block surface..
I could definitely see these grounding issues leading to magnetism of the reluctor also, as stated by others..
hope you solve yours! Just start grabbing grounds and pulling on them to see if anything is loose first!
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Joined: Aug 2023
Posts: 16
Likes: 11
From: PA
I'm glad to hear you figured it out! Sometimes we do things initially to set things up and keep it moving onto the next step, and forget to come back afterwards and button it up, or tighten ground lugs down, which has happend to me.. Good idea to always to go back and double check each step of the install to make sure it's buttoned up..
Enjoy that beast!
Enjoy that beast!
TECH Apprentice
Joined: Nov 2015
Posts: 384
Likes: 53
Hey Guys
i have a similar problem
the car started for the initial startup when swapped ( LS 6.0)
i turned it off = no start , no spark no fuel to injectors (Leads also to the crank sensor)
i put int a New AC DELCO Crank sensor= nothing
i put in a used crank sensor of my spare engine = started right up , i thought i solved it.
i turned it off= again No start and the same issues
the Term X shows me green and Green/blue indicator lights. I went in with the Holley tech support and we turned of the cam sensor to see if its syncing or the CRANK sensor only .
and we can confirm its the crank sensor.
i measured the Crank sensor Wire and it checked good (12V) no breaks in the wire.
i tried another Crank sensor i had laying around since NEW DOESNT MEAN WORKING = nothing!
the ground leads on the back of the heads are tight
I run 2 x Body grounds 1 to the body , 1x the Frame ( i welded a stud on to attach a big 0 Gauge ground.
12v switched is confirmed to be working , so no issues there
Holley asked me to send in the ECU for testing , its on its way back and they told me they didnt find any issues.
So i was hoping it was just a damaged ECU.
WHAT ELSE HAVE YOU GUYS DONE/ FOUND??
i will go back in and add another Ground Probbaly fromt he BLOCK to the Frame since the block is painted i will look into that just to be sure.
i have a similar problem
the car started for the initial startup when swapped ( LS 6.0)
i turned it off = no start , no spark no fuel to injectors (Leads also to the crank sensor)
i put int a New AC DELCO Crank sensor= nothing
i put in a used crank sensor of my spare engine = started right up , i thought i solved it.
i turned it off= again No start and the same issues
the Term X shows me green and Green/blue indicator lights. I went in with the Holley tech support and we turned of the cam sensor to see if its syncing or the CRANK sensor only .
and we can confirm its the crank sensor.
i measured the Crank sensor Wire and it checked good (12V) no breaks in the wire.
i tried another Crank sensor i had laying around since NEW DOESNT MEAN WORKING = nothing!
the ground leads on the back of the heads are tight
I run 2 x Body grounds 1 to the body , 1x the Frame ( i welded a stud on to attach a big 0 Gauge ground.
12v switched is confirmed to be working , so no issues there
Holley asked me to send in the ECU for testing , its on its way back and they told me they didnt find any issues.
So i was hoping it was just a damaged ECU.
WHAT ELSE HAVE YOU GUYS DONE/ FOUND??
i will go back in and add another Ground Probbaly fromt he BLOCK to the Frame since the block is painted i will look into that just to be sure.
Teching In
Joined: Aug 2023
Posts: 16
Likes: 11
From: PA
If you pulled on your grounds to double check them to be tight, and the crimps are good, and solid.. Then your going to have to check your airgap between the sensor and reluctor wheel.
I'm not 100% sure on the exact range for the sensor but I believe it should be around .027-.040.. usually people that have this issue find their gap is something like .050-.070..
I don't think the holley can read over .040 Gap
There are a few YouTube videos on how to measure the gap, rotate the engine while looking in the sensor hole to besure your reluctor is on a flat raised portion of the wheel where your sensor will go in the block. Youll need a bit of modeling clay, playdo, or something similar stuck to the end of the sensor and a drop of oil on the reluctor wheel itself to make sure the clay only stays stuck to the sensor.. stick sensor down in, bolt down, remove, then you can either let the clay harden or just very carefully remove clay off the tip of the sensor and measure carefully with a caliper, vernier, micrometer..
Have you had the crank out of the engine? Was it magnafluxed?
Better look inside where the sensor goes while rotating the engine over to make sure your reluctor is not delaminating also.
Also make sure you use only gm, or acdelco crank sensors.. no autozone/advanced sensors.. I mightve even read some discrepancies between some Delco sensors might exist
I'm not 100% sure on the exact range for the sensor but I believe it should be around .027-.040.. usually people that have this issue find their gap is something like .050-.070..
I don't think the holley can read over .040 Gap
There are a few YouTube videos on how to measure the gap, rotate the engine while looking in the sensor hole to besure your reluctor is on a flat raised portion of the wheel where your sensor will go in the block. Youll need a bit of modeling clay, playdo, or something similar stuck to the end of the sensor and a drop of oil on the reluctor wheel itself to make sure the clay only stays stuck to the sensor.. stick sensor down in, bolt down, remove, then you can either let the clay harden or just very carefully remove clay off the tip of the sensor and measure carefully with a caliper, vernier, micrometer..
Have you had the crank out of the engine? Was it magnafluxed?
Better look inside where the sensor goes while rotating the engine over to make sure your reluctor is not delaminating also.
Also make sure you use only gm, or acdelco crank sensors.. no autozone/advanced sensors.. I mightve even read some discrepancies between some Delco sensors might exist
Last edited by Area5150; Oct 17, 2023 at 06:23 AM.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
In another thread today, the OP discovered that his four (4!) new crank sensor, including a GM sensor from Amazon were "FAKE". Only the sensor bought from a GM dealer worked.
https://ls1tech.com/forums/pcm-diagn...l#post20524776
Interestingly what he thought was a genuine GM sensor had the wrong logo on the packaging. He was stunned that Amazon sold a fake product.
I responded that Amazon also sells fake Walbro fuel pumps and other parts. I found that parts from Summit Racing to be more likely genuine.
https://ls1tech.com/forums/pcm-diagn...l#post20524776
Interestingly what he thought was a genuine GM sensor had the wrong logo on the packaging. He was stunned that Amazon sold a fake product.
I responded that Amazon also sells fake Walbro fuel pumps and other parts. I found that parts from Summit Racing to be more likely genuine.
Teching In
Joined: Aug 2023
Posts: 16
Likes: 11
From: PA
Thanks for the reply!
Yea I wish amazon would #1 stop carrying these counterfeits, or #2 would be sued by all these American companies affected by this horsesh!t!
I found out the hard way with elgin lifters, and a few other purchases that obviously weren't real from Amazon. With the Elgins I knew something was up when the box containing the lifters showed a made in China sticker front and center when opening.. Amazon told me to reach out to the seller for a refund, which the seller wanted 60 bucks to ship back..
Yea I wish amazon would #1 stop carrying these counterfeits, or #2 would be sued by all these American companies affected by this horsesh!t!
I found out the hard way with elgin lifters, and a few other purchases that obviously weren't real from Amazon. With the Elgins I knew something was up when the box containing the lifters showed a made in China sticker front and center when opening.. Amazon told me to reach out to the seller for a refund, which the seller wanted 60 bucks to ship back..