96 vortec help

[makovai]

got a 96 silverado 5.7 liter. Ran fine when i parked it 2 days ago. now it wont even fire.

Fuel pump is new and working fine.

The weird part is when i crank it over theres nothing but cranking, when i turn the key off it feels like it wants to fire. But only when i turn the key off. It really seems like ignition to me.....but where?

I hate newer cars. My 72 blazer is so ez to work on. Any help would be appriciated.

 

[sweetk30]

have you checked the dist cap and rotor? thay are a super bad setup. carbon trac and junk build up bad. t20 for cap screws and t15 for rotor screws.

also the dist it self is prone to bad bushing in top and or striped gear on dist.

 

[makovai]

have you checked the dist cap and rotor? thay are a super bad setup. carbon trac and junk build up bad. t20 for cap screws and t15 for rotor screws.

also the dist it self is prone to bad bushing in top and or striped gear on dist.

i started to check that and i couldn't see the top of the screws......now that you told me what they are ill dig into tommorow. thanks.

 

[noJeepshere]

my 99 yukon did the same thing this winter. what would happen is it wouldnt start, then act like it wanted to then die. i noticed the "security" light in the upper right corner of the dash blinking. after 5 or 10 minutes it'd stop and i could drive. couple days fine, then it'd do it again. i thought the alarm system was crapping out, but in jan the starter crapped instead. replaced it and no problems since. hope that helps.

 

[dyeager535]

If it were older I'd think maybe the ignition switch adjustment, don't know enough about the newer trucks to state for sure though. Just an idea.

 

[virgilh]

vortecs are also known for eating dist gears check that too mine did it at 203000 miles for the third time

 

[bigblock72]

Make sure and check the battery cables. The positive cables like to corrode, especially the spacer between the cables. I have seen a few that will get just enough corrosion to drop the voltage to the fuse box. The low voltage will keep the computer from turning on. Make sure you replace the long battery terminal bolt and spacer, then remove the plastic cover from the cables and clean all of the blue/green goo off.

If that doesn't fix it check the fuel pressure, I know you said you have a new pump but check it anyway. If the fuel pressure is below 52 psi it will not start.

The other thing I sometimes see is the dist cap going bad, it will arc between #6 terminal and the coil terminal. The arc actually occurs internally so it's hard to tell when it happens.

I listed these problems in the order of what's most common to least common. Good luck and let us know what you find.

 

[makovai]

Excellent suggestions guys......I'm gonna try all tonight and see where i get.

thank you

 

[makovai]

ok...got home and heres what i found.
I have this cool gadget that lights up when theres spark. plug it onto the sparkplug and the other end to the sparkplug wire. no spark. I figure it has to be the coil because i checked the distrubutor and it looked great. cap rotor look great and rotor was turning.

Got new coil. Nothing. although as its darker now i can see a very faint spark with my little gadget.

I took that unit to my ol faithful blazer and it lights up like sun.

So i have a spark its just really really really whimpy.


Now what?

 

[dyeager535]

Your plug wires junk?

It does sound like you've got some sort of power or ground issue. Based on your description of it sounding like it almost starts when you let off, voltage to the system might be too low (as suggested earlier by another poster) because everything is going to the starter. Put a voltmeter on your fuse panel, see what voltage drops to when you crank it. My experience has been no lower than 10V.