Distributor, spark to it, no spark from it - STUMPED

[bassplayaz06]

So I pulled the 350 out due to leaking intake gaskets. Decided to just replace all the gaskets due to having 250K miles. Did a rear main seal, head gasket job, oil pan gasket, basically regasketed everything. I put it all back together and back in the truck, turn the key, no start. turns over easily, has compression, fuel, and air. So i proceed to check the distributor. Checked all the wires with a multi-meter, they're all good.

So what's happening is the coil is sending the spark into the dist., but the dist. isn't sending it out to the spark plug wires. I know that for sure because i hooked the timing light up to the coil wire, and the spark plug wires to see where there is spark and where there isn't.

Checked all these, everything came out good.

plug wires
coil to dist. wire
coil to dist. harness
ign. module

There is 12v going from ign. switch to coil, and 12v going from coil to ign. module.

I saw that the cap and rotor were a bit scored, and the center pin on the top of the cap was broke, so i replaced both.

turned the engine over, still no spark. put in an MSD street fire coil, still no spark.

checked all the grounds on the block, they're all good. So i figured even though it checked out fine, the ign. module had gone bad. So i bought an MSD EFI Pro Billet dist. Put it in, plugged it all up, still no spark.

I am completely stumped on this one. Looked all over the internet, saw that many people have had this problem, but could not find one with the EFI dist. like ours. All the ones i found here HEI dist's.

 

[TruckinAin4Sissies]

Check all your sensors.
IMO Obviously the computer doesn't see something right and is in a "no start" mode?



TA4S

 

[bassplayaz06]

I've gone through the wiring harness and checked that everything is connected. If you unplug the 4 pin connector going into the ign. mod, would it still run? From my understanding, that just controls the computer's timing advance.

 

[GMstrong]

when your cranking the motor the ign module is controlling timing past 400 rpm the ecm controls the timing,Have you checked some fuses?which ground did you check?Did you check and clean the ecm ground?

 

[bassplayaz06]

I've checked the fuses and relays, and all the grounds in the engine bay. I haven't checked the ecm ground. If the ecm wasn't grounded properly, what could some of the symptoms be?

 

[Talisman]

Do the earlier motors use a crank sensor?

 

[bassplayaz06]

I don't think so, i know mine doesn't have one.

 

[4x4incountryboy]

stupid but is the distributor cap bad? ive had issues before and swapped the cap and be good to go
^^^nevermind over read what you stated in the question my bad

 

[bassplayaz06]

Well I had spark for about 10 seconds. I unplugged the EST wire used for computer timing, turned it over, and it backfired, puffed out the TB. turned the key again, and it did the same thing. I adjusted the timing to see what it would do, and the spark stopped.

Is it possible that the computer sees a problem, and stops the spark?

 

[4x4incountryboy]

its possible, the computer is the brain for pretty much everything