Have a 98 blazer LT with the "w" 4.3. November of 2016 I installed a brand new motor from gearhead engines. Run great until April 2017. Ended up installing new fuel pump, filter and pressure regulator. Started but was missing terribly. 1 by 1 replaced plugs, wires , cap rotor button. After replacing button and a couple vacuum lines it run better than ever. Drove from work Thursday with no problem. Pulled in shut it off and went inside just long enough to shower and it wouldn't start. Cranks good and check engine light came on but scanner says it can't find any DTC's.need possible faults please. Will explore ideas, just need it running and am stressed from thinking and tired of time and money in it. Thanks in advance for any advice.

 

try another scan tool if available. Does the vehicle have a theft deterrent system...any theft deterrent lights on?
what brand of plugs did you install?

basic diagnosis for a crank no start with no dtc:
-check for spark at the spark plug wires with a spark tester.... check more than 1 plug

-check for fuel pressure
-check compression

 

Thanks for the replies everyone, it ended being the crank sensor. Installed a new one and it started right up and runs smooth as butter. Thanks again everyone.

 

Do you still hate that Blazer?

 

I know once I get all the little annoying kinks worked out it'll be worth it. Just seems every time its raining ***** I get hit with a dick.