No fuel, no spark, no start

[Fierospeeder]

This might do it for you:

ignition system test

I don't see a test utilizing a scope listed on there before GM says to replace the pickup coil.

GM's training will refer to a scope.

Would you only put a multimeter on a battery and say "yup, the battery is good" or spend more money for a better tool. Such as a load tester. Then have a better answer to see if the battery is good or not.

 

[thezentree]

Chris. You are hell on battery cables. Because you touched mine yesterday, my truck didn't start this afternoon. Seriously.





Some people, geeez.......






(Oh, and for the record, my truck now runs, a little 5/16 wrench action had me moving along in no time.)

 

[dyeager535]

GM's training will refer to a scope.

Would you only put a multimeter on a battery and say "yup, the battery is good" or spend more money for a better tool. Such as a load tester. Then have a better answer to see if the battery is good or not.

I'd do what GM tells the people in the field to do, how they tell them to do it. If GM's training regimen teaches one thing, yet prints manuals with component tests that work faster with less special equipment, that's their issue.

I wouldn't even compare testing a battery to testing a pickup coil per the manual.

In any case, everything suggested was incorrect, and the poster got lucky (as we all do at some point) and found it before spending too much money.

 

[Fierospeeder]

I'd do what GM tells the people in the field to do, how they tell them to do it. If GM's training regimen teaches one thing, yet prints manuals with component tests that work faster with less special equipment, that's their issue.
I wouldn't even compare testing a battery to testing a pickup coil per the manual.
In any case, everything suggested was incorrect, and the poster got lucky (as we all do at some point) and found it before spending too much money.

Your not even trained by GM or any automotive technical school, so you dont know what to do in the field. Or have the necessary skills to diagnose anything. Wouldn't your first post tell him to check system voltage? oh ya, your not trained.

Do you have any GM training manuals that suggest they dont refer to using scopes? If you go back to the copyrighted material, you notice GM states to check the module using a special tool. (according to you, you said.. "with less special equipment") And you have an issue with material being old. That service manual is from 86. Even back in 86 they were using scopes. Go to any repair shop and ask them about their purchase of a 30,000 dollar scope in the 80s. But i bet all the shops use is a light tester to backprobe into the PCM

I can even quote you where you said it is better to replace parts then to diagnose the problem. Glad the user didn't start listening to your posts and start replacing all the sensors when it was just a simple battery cable.

real way to test an alternator scope
real way to test sensors scope
real way to test a fuel pump, scope
real way to test the ignition system scope
real way electrical engineers test circuit boards, scope

backyard mechanics

 

[Fierospeeder]

Some sensors report rotational speed by generating AC voltage when two magnetic materials move toward and then away from each other. The pick-up coil in a distributor and many crank sensors and anti-lock brake sensors use this principle of operation.
PICK-UP COIL, CRANK SENSOR, ANTI-LOCK BRAKE SENSOR
AC voltage produced by an induction-type sensor will vary in proportion to engine/wheel speed.
Devices that produce AC will usually have two wires (+ & -) carrying the AC signal.
Many service manuals give specifications for resistance (ohms) testing of these sensors.
Resistance testing alone is incomplete. A weak magnet, producing less voltage will not be revealed.
Using the DMM to verify voltage during actual engine operation/wheel turning is a more reliable test.
Because DMM voltage is averaged, the voltage can read as expected but not be the clean signal that is needed by the module or computer.
The most reliable test of an induction-type pulse generator sensor is made using a labscope.

pretty obvious to use a scope reading this.

 

[dyeager535]

I'm glad the user didn't listen to you, he wouldn't be fixing his truck. Damn "backyard mechanics" as you refer to everyone here that doesn't work in a shop apparently.

In case you didn't notice, the poster didn't test the module according to that chart before discovering the problem in the first place anyways, nowhere did I say replace something.

You had no posts on this until you jumped in with needing a scope to solve everything (and how "lots of things" can't be wrong, apparently more than 10 is lots? heh) and how to test the pickup coil ALONE (don't see you jumping in saying test system voltage anywhere) which wasn't the correct diagnosis nor course of action, along with every other post. Before throwing out how much better you think you are than everyone else, perhaps you should be able to solve the problem at hand, instead of pointing out how GM's manuals are wrong. Then talk smack.

Even though this post was resolved, and you posted information that didn't help the poster, you continue to drag it out. Instead of learning from his solution to this problem, you'd continue to talk about how tools that didn't solve his problem are necessary.

I'm done with this post. I know what the cause was, and I learned something from his experience.

 

[Fierospeeder]

I'm glad the user didn't listen to you, he wouldn't be fixing his truck. Damn "backyard mechanics" as you refer to everyone here that doesn't work in a shop apparently.

You had no posts on this until you jumped in with needing a scope to solve everything (and how "lots of things" can't be wrong, apparently more than 10 is lots? heh) and how to test the pickup coil ALONE (don't see you jumping in saying test system voltage anywhere) which wasn't the correct diagnosis nor course of action, along with every other post. Before throwing out how much better you think you are than everyone else, perhaps you should be able to solve the problem at hand, instead of pointing out how GM's manuals are wrong.

Even though this post was resolved, and you posted information that didn't help the poster, you continue to drag it out. Instead of learning from his solution to this problem, you'd continue to talk about how tools that didn't solve his problem are necessary.
.

please quote me where i say everyone on here is a backyard mechanic. Because i know i was just refering to one person.

Actually, i did post with trying to help the "user". I told him to test the device with a scope. And if he can wait till tomorrow, i would send him copies via email of all the things for his truck. That would include wiring diagrams, theories of operations and test procedures.

Ya many things can be wrong maybe he has a flat tire which is causing him not to have a spark.

Never said the GM manuals are wrong. You are wrong in your method of diagnostics. Has GM trained you to be a technician? I havn't seen you yet say your a real mechanic. I know your profile says "governement contractor" not even close.

Me draging this post out? You got all huffy puffy, when i told the user to test his sensor with a scope. Id rather him test it the real way before replacing parts like some people do.

I don't see a test utilizing a scope listed on there before GM says to replace the pickup coil.

If you were a mechanic you would realize what "real" tools are in the field. But your going to nick pick on how things are "suppose" to be diagnosed.

Diesel did a good job in helping the user out. So i dont see how no one helped the guy out.