'97 Blazer, toasted another Ign. module

[mike2004tct]

What's up with this thing.

July, I replaced the module, cap, rotor, coil, and distributor.
August, I replaced the Distributor again, module again, and VCM (computer)
October, replaced the fuel pump.

Yesterday, truck wouldn't start.
Had good spark and fuel pressure (64 psi before and while cranking).
Checked the sparkin with a timing light, noticed a double blip on plug #1, then a steady spark light during cranking. Constant light on #3 and #5.

Swapped out the Delphi module with another spare Delphi I have. No luck.
Swapped #2 Delphi with a cheapo Autozone module, truck fired up after 5 seconds of bucking (probably flooded from all the cranking).


So, what's causing all these problems.

Ran thru the harness with a "codes/symptoms" cheat sheet MT2500 e-mailed me.
No codes whatsoever. (the old VCM threw a P1351)
Could it be the crank position sensor (only part I haven't replaced)?

I'm really starting to get P.O.ed with this thing.

[old_master]

If the primary resistance in the ignition coil is excessive, it can take out the ignition module. Might be worth checking. With the coil wire and coil connector disconnected: Positive to negative terminals in the coil should be .1 ohms. Positive terminal to the coil output should be 5K to 25K ohms. Coil positive to coil case ground should indicate infinite resistance.

[mike2004tct]

Originally Posted by old_master

If the primary resistance in the ignition coil is excessive, it can take out the ignition module. Might be worth checking. With the coil wire and coil connector disconnected: Positive to negative terminals in the coil should be .1 ohms. Positive terminal to the coil output should be 5K to 25K ohms. Coil positive to coil case ground should indicate infinite resistance.

I'll check those readings.

I should add that in addition to all the stuff I replaced in July, the coil was also replaced. Guess I missed that in the first post.
I edited that post.

Thanks.