Well, as you can see, in the pictures, I have used all the diagnostic info on the site, google, and I have come up with the conclusion:

1. or the distributor gear is wrong
2. the gear that drives the distributor gear is wrong
3. someone messed up or steal the distributor and putted one that was damaged or didnīt worked.

The story goes...

2000 Blazer, 2nd gen, 400K+ Km, CPI system, was tooked to 2 different mechanics. One changed the timing chain, the other did a "manteinance" to the spider fuel system.

The car ran rich (confirmed with scan tool, fuel trim was -30% most of the time, other times -15%) and black smoke when accelerating hard, didnīt run well.

Last week the engine just didnīt start anymore, ODB scan tool to the action P1351 code was showing, also while cranking. Checked using the instructions and nothing came up.

Further checking, the CKP cable sensor was broken, and the signal cable showed +10v instead of 5 (guessed it was damaged). Changed connector and sensor altogheter. Now it showed a code relating to the CKP performance, donīt remember the number, but I knew was related to it, since it didnīt show any rpms while cranking (havenīt checked the voltage but if it showed rpms then it means that is working).

Installed old sensor back, and it showed rpms again, still P1351 shows, decided to check the distributor and the balancer. I found this:






The only way it would line up was to actually move the whole crankshaft about 20 degrees. The thing is that the Blazer ran before, ran like crap but it ran, and the next day it didnīt.

Also, one thing is that before, I saw ignition advance while cranking, now it shows zero. Plus, at TDC it doesnīt align at all the distributor, there is something wrong right?

So, I believe the P1351 is being set because there is something wrong with the dizzy.

Any pointers?

 

are you running the 4.3L?

 

Indeed 4.3L, the car was taken to a reputable garage and is been 4 days and they couldnīt start the truck consistenly. Apparently the ECU seems to be dying. I disagree a little of that, it seems too odd.

 

If they think it is the ECU, just swap it from another 4.3 and if the problem persists there is nothing wrong with the ECU