Need help engine gurus*Update, no spark*

[dfl701]

it cranks sometimes/ im willing to bet i could go home right now and crank it and it would run for a few minutes/seconds and then die. and i probably wouldnt be able to get it to crank the rest of the night. thats usually what has happened the past two weeks

 

[topless jackass]

Automatic? try holding up on your shifter when it won't crank or putting it in neutral. If it's an issue where it won't crank we can steer away from the distributor altogether. seems like an ignition switch problem or starter problem. Check wires to starter (fusible links and stuff down there) too.

 

[dfl701]

ok so i got some work done this weekend. come to to find out one of the wires happened to fall on the header and burned half way through. however, still doesnt fire. i need to buy a condensor for the distributor. i have replaced just about everything else inside of the cap though, so thats my last part to replace. still not getting spark to the engine though. i know the firing order for the truck, but whats the layout for the wires on the cap? i want to make sure they are all right.

 

[K5dreamer]

layout on the cap is in firing order. if you look at the cap from above it will look something like this.... (hope this works)

-0 - 0-
0 --- 0
---0
0 --- 0
-0 - 0- <= this one should be connected to the #1 cylinder.

then ordered clockwise in the firing order, that being....

REAR (FIREWALL)

-(6)---(5)
(3)-----(7)
----(C)
(4)-----(2)
-(8)---(1)

FRONT (RADIATOR)

with the "bottom" of the above layout being towards the front of the vehicle, and the top being towards the firewall. left would be passenger side, right would be driver side.

 

[dfl701]

layout on the cap is in firing order. if you look at the cap from above it will look something like this.... (hope this works)

-0 - 0-
0 --- 0
---0
0 --- 0
-0 - 0- <= this one should be connected to the #1 cylinder.

then ordered clockwise in the firing order, that being....

REAR (FIREWALL)

-(6)---(5)
(3)-----(7)
----(C)
(4)-----(2)
-(8)---(1)

FRONT (RADIATOR)

with the "bottom" of the above layout being towards the front of the vehicle, and the top being towards the firewall. left would be passenger side, right would be driver side.

nice draw up! thats how i have it IIRC. just wanted to double check i didnt cross any up.

 

[Philly87]

Just something to check real quick. Yank the distributor cap off and have someone crank the motor. Make sure the distributor is turning.

I've seen similar issues where the motor will fire at times and not at all and it was related to the distributor gear sheering a few teeth off.

Similar to a flexplate (flywheel) when they get a few teeth knocked off. We've all heart that famous grind and then the motor spins.

If the distributor doesn't turn yank it out and check the distributor gear and camshaft gear. If both are ok possibly a timing chain issue...

Phil
MSD Ignition

 

[dfl701]

Just something to check real quick. Yank the distributor cap off and have someone crank the motor. Make sure the distributor is turning.

I've seen similar issues where the motor will fire at times and not at all and it was related to the distributor gear sheering a few teeth off.

Similar to a flexplate (flywheel) when they get a few teeth knocked off. We've all heart that famous grind and then the motor spins.

If the distributor doesn't turn yank it out and check the distributor gear and camshaft gear. If both are ok possibly a timing chain issue...

Phil
MSD Ignition

i will have to look at that. i know im not gettin spark to the plugs so i know it has to be from the distributor and back from there.

 

[Philly87]

One more quick note...

If you have an ohm meter (DVOM) you can check the magnetic picup for resistance to make sure it's ok.

Stock GM magnetic pickup will read somewhere in the 600 to 700 ohm range.

Be sure to check it at the point the motor will not start. If bad typically is will show open or infinate resistance.

Phil
MSD Ignition