Parts Cannon strikes again

[clinebarger]

I find these kind of jobs very interesting! The sad thing.....This is a guy that has sent me work in the past (Owns a Vending Company), But always whines/complains because I use OE parts that are naturally more expensive.....So he deals with other shops that will gladly use cheap parts.

UNTIL they can't fix something! He calls me saying his 2002 Chevy Express 3500 box van has a wiring issue & that ALL the ignition components have been replaced but still has no spark.
Sure enough.....
Crank sensor, Cam sensor, Distributor cap, Rotor, Coil, & Ignition module are all new.

*Confirmed that it indeed has no spark out of the coil.
*Cam & Crank signals are present via Scan Data
*Has a good 5-Volt square wave signal from the PCM to the Ignition Control Module
*Has a Primary control signal output to the Ignition Coil from the Module, Along with having a 12-volt return from the Primary Windings (Meaning the coil has power)

There was NO positive Induction on the Primary Coil Control circuit, A good coil will spike the voltage on the Primary circuit past 100-volts when Secondary voltage is released/induced.
This coil was pulling the Primary Circuit all the way to ground....Meaning it's was probably shorted internally? I would have liked to put a Amp Clamp on the Primary to prove it out but this rig has a 300,000 miles on it & I'm not going to mess with the harness causing future issues!

Though I did go one step further that in all honesty I didn't have to.....
A Coil is a Coil, Standard 2 wire ones are anyway, I had some COP coils off a 2013 Ford 3.7L & adapted it to the GM coil connector.....Nice strong spark!!
In the moment, I was concerned about possible damage to the Ignition Control Module because the shorted Coil, But it had control so that's not likely an issue.

1st pic.....Good square wave from the PCM to ICM
2nd pic....Control signal on the Primary.....Negative Induction (Firing line going down)
3rd pic.....Ford COP adapted to the coil connector

 

[GMBoy]

Good job! You are a real mechanic/technician. Too many newer mechanics are just parts changers and guessing at a problem. You have used your knowledge and tools to properly diagnose the issue and I agree - new parts don't always mean you can skip looking there...especially when somebody else did the repairs with cheap parts. I enjoy tracking down hard to find problems and take my time looking and using proper diagnostics to pin point the issue and fix it right the 1st time.

Kuddos to you sir!!

 

[clinebarger]

Installed a new OE Delco coil, Van ran great after I cleared all the fuel out of the cylinders by "Clear Flooding" & taking it on a test drive.
Recommended a oil change ASAP.

Like clockwork he complained that the coil was under warranty from Autozone, I told him the bad coil is in the van & he's welcome to go have it warrantied. Weird that the original coil wasn't on the floor like the other parts that got shot at it, Though the coil is riveted to the bracket from the factory.
I wonder....What was the actual problem to begin with? If the shop changed the coil first. While in fact the crank sensor was faulty.....

That's why I TEST components, Throwing parts at a vehicle is foolish!

 

[Food Scientist]

Reads like I'm watching South Main Auto on YouTube. That would be funny if you did a post the way he talks.

Welcome back readers to the Clinebarger Auto website! Today I'm working on a 2002 Chevrolet! Express can with the big 5.7 liter. Engine doesn't run and came from another shop that threw the parts cannon at it.

 

[willbur]

I see a Standard parts box in the pic. Regarding non-OE parts and all the complaints about China Junk replacement auto parts, have you had good luck with this brand?

 

[Chris142]

So someone replaced the bad coil with another bad coil?

 

[53' Stude]

Originally Posted by clinebarger
Installed a new OE Delco coil, Van ran great after I cleared all the fuel out of the cylinders by "Clear Flooding" & taking it on a test drive.
Recommended a oil change ASAP.

Like clockwork he complained that the coil was under warranty from Autozone, I told him the bad coil is in the van & he's welcome to go have it warrantied. Weird that the original coil wasn't on the floor like the other parts that got shot at it, Though the coil is riveted to the bracket from the factory.
I wonder....What was the actual problem to begin with? If the shop changed the coil first. While in fact the crank sensor was faulty.....

That's why I TEST components, Throwing parts at a vehicle is foolish!



Wish I was working with you. We have two "glorified hack/parts throwers in our shop. Finally fired one yesterday

Great work as always sir

 

[LotI]

Like Ron Ananian, the Car Doctor, says...NEW means never ever worked!

 

[WyrTwister]

There's your problem , lady !

 

[mk378]

Does the service manual say to test the coil with an ohmmeter? If it does, does that not working coil pass? I bet it does.

 

[JTK]

Very cool.

I'm surprised a 2002 would still have a distributor cap and rotor!

 

[bdcardinal]

I love reading about parts cannon fails. Had a shop call in yesterday that was working on a 2016 F-650 with a 6.7. They had a P2002 code and wanted whatever the book said to "make it go away." I looked it up on OASIS and it pointed to either a NOX Trap sensor or a DPF. They wanted to know what those meant.

 

[joegreen]

Very nice. I like when you post up stuff like this. Reminds me of scannerdanner.

 

[02SE]

A buddy of mine works as a salesman at a BMW dealership. He's a former Mechanic who owned his own Fuel Funny Car. Apparently all of the competent Mechanics who could actually diagnose an issue and fix it, have left to start their own garages. All that's left are recent Tech School graduates that can hook up a code reader, and swap parts. I guess the 'parts cannon' approach doesn't matter to the customer, as long as the car is under warranty.

 

[bdcardinal]

Originally Posted by 02SE
A buddy of mine works as a salesman at a BMW dealership. He's a former Mechanic who owned his own Fuel Funny Car. Apparently all of the competent Mechanics who could actually diagnose an issue and fix it, have left to start their own garages. All that's left are recent Tech School graduates that can hook up a code reader, and swap parts. I guess the 'parts cannon' approach doesn't matter to the customer, as long as the car is under warranty.


There are some manufacturers where the flow chart will hit a point and say "replace with known good part and retest" which of course if that doesn't fix it the "known good part" can't be returned or billed to warranty.

Unrelated, I got tickets to the Winternationals for Saturday. Taking my mom who has never been, but is really excited to see Top Fuel in person.

 

[tiger862]

The weirdest one I had was a new Toyota that customer stated buzzer didn't work when key was in and door open. Service writer stated he didn't see seat belt warning on either and other shop stated no problem found along with second shop stated normal operation with less than 1000 miles. I checked flow chart nothing wrong called engineer to get permission to remove instrument cluster from inventory. New instrument cluster fixed it. Many examples of parts cannon at dealership (IE O2 code and 02 sensor replaced not the problem).

 

[maxdustington]

Originally Posted by JTK
Very cool.

I'm surprised a 2002 would still have a distributor cap and rotor!
Very last year of SBC from the factory AFAIK. They went to the LS along with the 2003 facelift.

 

[clinebarger]

Originally Posted by mk378
Does the service manual say to test the coil with an ohmmeter? If it does, does that not working coil pass? I bet it does.



Not sure if the FSM calls to Ohm the coil primary. To tell the truth......I don't Ohm components very often! It may work well for other mechanics, But I've never seen much value in it. The guy I was mentored by taught me to use Voltages & Amperage.

 

[clinebarger]

Originally Posted by Chris142
So someone replaced the bad coil with another bad coil?


Not sure as so many components were changed.......'96-'02 Vortec coils aren't exactly known to fail. I could probably count on one hand how many I've replaced over the years. Same goes for the ICM.

 

[GMBoy]

Originally Posted by willbur
I see a Standard parts box in the pic. Regarding non-OE parts and all the complaints about China Junk replacement auto parts, have you had good luck with this brand?



I can vouch that I have had good experiences with SMP parts. Good price and good fit. I've used their coils and misc sensors all fine.