What can kill an ignition coil?

[truckmen]

Still trying to get my 96 Ran 2500 S/T running. It cranks but doesn't fire. Could something destroy a coil? I replaced it but still cannot seem to get spark. I even ran a temporary hot lead to.the primary side of the old coil and the new replacement coil - no spark.
Is there something I am missing?

 

[pacofortacos]

Chances are it isn't the coil.
To test a coil by itself, pull the coil wire from the cap and put the dist. cap end 1/4" from ground.
Now take and put 12 V on the + coil lead and quickly intermittently ground the - coil lead. You should see a spark when you make and break the ground connection.

 

[truckmen]

Chances are it isn't the coil.
To test a coil by itself, pull the coil wire from the cap and put the dist. cap end 1/4" from ground.
Now take and put 12 V on the + coil lead and quickly intermittently ground the - coil lead. You should see a spark when you make and break the ground connection.

Hello pacofortacos,

I am working on the truck now and am looking into the fuel system. It appears I have no fuel pressure and cannot hear the fuel pump running when turning on the ignition. I've actually had posted earlier about this and didn't remember so I have 2 threads going on this problem at the moment.

 

[pacofortacos]

Hi, do you have a scanner or will your truck pull up codes on the dash via the
Key on (run position), key off, key on, key off, key on ??

If you can pull up codes then disconnect your battery terminals - while disconnected turn the key to the start position and hold for 5 secs. Turn key off.
Reconnect the battery terminals and try to start the truck.
If it doesn't start, see what codes there are.

That is the easiest way to start trouble shooting.
It could just be a bad fuel pump/pump relay, asd, etc etc etc.

 

[truckmen]

Hello Pacofortacos,

Okay, I try those steps in a few hours when I arrive back to the shop. Running errands at the moment, and I'll get back to you.

 

[Quyonmob]

GM trucks were wired for a while that no fuel pressure meant no spark.

 

[truckmen]

GM trucks were wired for a while that no fuel pressure meant no spark.

Do you mean that if there is no fuel pressure, the system won't allow spark?

 

[truckmen]

Hi, do you have a scanner or will your truck pull up codes on the dash via the
Key on (run position), key off, key on, key off, key on ??

If you can pull up codes then disconnect your battery terminals - while disconnected turn the key to the start position and hold for 5 secs. Turn key off.
Reconnect the battery terminals and try to start the truck.
If it doesn't start, see what codes there are.

That is the easiest way to start trouble shooting.
It could just be a bad fuel pump/pump relay, asd, etc etc etc.

Okay, I did exactly as told. No start and no trouble codes

 

[pacofortacos]

Hmm. Do you have a scanner? One that can actuate relays?

I was hoping you would get a code about either the cam or crank sensor - which is why I said to disconnect the battery.

Does your truck have a fuel pump relay or use an ASD relay?

No weird anti-theft going on is there?

Did you personally ever have it running? If so, what happened to make it stop?

 

[Quyonmob]

Do you mean that if there is no fuel pressure, the system won't allow spark?

Yep, exactly. Was true in 95 GM TBI, but 96 was a one off year. Could be the case with dodge too. No oil pressure can cause it too

 

[pacofortacos]

Yep, exactly. Was true in 95 GM TBI, but 96 was a one off year. Could be the case with dodge too. No oil pressure can cause it too

Fuel pump should turn on for a few seconds the first time the key is turned to run or start.

Would be easy to find with a wiring diagram.