I have a 1998 chevy blazer LS 4x4 with 4.3 vortec. Replaced ignition coil, spark plugs, plug wires, distributor cap and rotor, camshaft and crankshaft sensor, map sensor and fuel filter. The tach won't work and it wants to die at idle after a few minutes of it running. Only code its throwing is the P0340. I cant seem to figure out whats causing it to be running this way. Im still going thru the wiring to see if I over looked something. Anyone have any ideas of what could be the culprit?

 

I got that once when I forgot to plug in the distributor, but I assume you've already checked that.

Does your scanner check cam retard? If so, see if you can get a reading.

 

no my scanner doesn't. But im waiting for Friday to borrow a snap on scanner.