i have been having problems with my truck too trying to find out the problems ive down series of test and to test to see how the spark was, i got an extra spark plug wire and spark plug and uplugged all the spark plug wires from the cap and got my extra plug and plug wire and plugged it into each port and grounded the plug to see if they all had equal spark, you should try that, but with these trucks as soon as you think you know the problem they throw you curve *****, so id test other things like fuel pressure and what not, also check all your fuses, i had an ENG 1 fuse that kept instantly blowing when i would put in a new one, so i found that an O2 sensor's connnector was grounding out, and pretty much all your important sensors and your PCM all go to that fuse, so check that, also recheck your codes because that P0174, aught to be important so id deffidently check the fuel presssure because running lean isnt a good thing

 

im really leaning toward the crankshaft sensor. it wasnt bad before the top end rebuild but i had to unplug it and remove the ground next to it to remove the harness. i got everything put back but i am throwing that code now so im gonna re-check all connections and ill keep you posted. does anyone know if that sensor will kill it no matter what rpm im at?

 

ddoes anyone know how hard a job it is to change a crank sensor on a 97 z71

 

ok guys i think i got it figured out. i replaced the crank sensor today and removed the ground for the sensor. i cleaned the block, ground connector and bolt for the ground. i also cleaned up the connector for the sensor. so far so good. everything seems to be working right nd most importantly its not dieing on me. thanx for the help. ALSO...IT IS VERY EASY TO CHANGE THE CRANK SENSOR. ONE 8MM BOLT.

 

i wish i could have replied faster, while trying to find out whats wrong with mine i tried replacing the crank shaft postion sensor and it wasnt bad

 

It may sound dumb, but check your ground at the back of the engine top, right behind the distributer. i had tore down my 96, and after several months of hassel, new fuel pumps , run fine/shut off/no start, etc. i found the ground wire to be loose. one indicator was the turn signals would cause the voltage guage to fluxuate

 

No it is timing related. When you pulled dist. These are preset you cannot time.
You have to have a scan tool that will do cam retard off set.
Or take it to a dealer.. have it done. Reason running lean .. crank sensor , cam sensor out of sync .

 

also check fuses, i had the engine 1 fuse blowing and finally found the O2 sensor connector was grounding out and almost all your major sensors are wired to that fuse

 

well I bought the software for my laptop to make it a diagnostic computer to run check on it but all in all changed the CMP camshaft sensor the CKP crankshaft sensor retimed and it purrs like a skint cat now

 

funny because i was having the same crappy problem and i replaced those too, unfortunatly i had to replace the injector spider and fuel pump in the process