98 CHEVY K1500 5.7 VORTEC WON'T START!! THOUGHTS/INPUT PLEASE!! I HAVE A P1345 CODE, CRANK/CAM SENSORS MISMATCH.

[MMartin401]

98 CHEVY K1500 5.7 VORTEC WON'T START!! THOUGHTS/INPUT PLEASE!! I HAVE A P1345 CODE, CRANK/CAM SENSORS MISMATCH. I WAS TOLD TO CHECK SPARK AS PART OF THE PRELIMINARY DIAGNOSIS.

 

[Schurkey]

98 CHEVY K1500 5.7 VORTEC

WON'T START!!

Won't crank, or cranks but won't run?

TOTALLY different diagnostic paths.

I HAVE A P1345 CODE, CRANK/CAM SENSORS MISMATCH.

Fix that as soon as you get it running.

Wouldn't hurt to verify that the distributor actually turns when the engine is cranking, and that the basic distributor installation is correct via the molded-in numbers and arrows on the original distributor body.

I WAS TOLD TO CHECK SPARK AS PART OF THE PRELIMINARY DIAGNOSIS.

And the results are...?

Use a spark-tester calibrated for HEI ignitions.

My favorite style (but there are others):
www.amazon.com/dp/B003WZXAWK/?coliid=I3S98D7T1J0RLJ&colid=2VLYZKC3HBBDO&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

 

[L31MaxExpress]

In addition to the above, could be a bad crank sensor as well. But until you diagnose what it is, just aiming into the wind.

 

[MMartin401]

Won't crank, or cranks but won't run?

TOTALLY different diagnostic paths.


Fix that as soon as you get it running.

Wouldn't hurt to verify that the distributor actually turns when the engine is cranking, and that the basic distributor installation is correct via the molded-in numbers and arrows on the original distributor body.


And the results are...?

Use a spark-tester calibrated for HEI ignitions.

My favorite style (but there are others):
www.amazon.com/dp/B003WZXAWK/?coliid=I3S98D7T1J0RLJ&colid=2VLYZKC3HBBDO&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

Thank you very much for the reply, It cranks but won't start! It started 2 weeks before the no-start! I was told if I have spark, not tested yet, that the timing chain isn't broken. The distributor has the cam sensor integral to it based on a very knowledgeable friend! I have a very cheap inline spark tester but doing it by myself so need to extend the leads so I can see whether or not that light proves spark as I crank it! Thanks for the calibrated tester link!

 

[MMartin401]

In addition to the above, could be a bad crank sensor as well. But until you diagnose what it is, just aiming into the wind.

THANKS, IS THERE A WAY TO DIAGNOSE/TEST THE CRANK SENSOR?

 

[L31MaxExpress]

Thank you very much for the reply, It cranks but won't start! It started 2 weeks before the no-start! I was told if I have spark, not tested yet, that the timing chain isn't broken. The distributor has the cam sensor integral to it based on a very knowledgeable friend! I have a very cheap inline spark tester but doing it by myself so need to extend the leads so I can see whether or not that light proves spark as I crank it! Thanks for the calibrated tester link!

Just FYI a Vortec will run without a cam sensor all day long. A cam sensor itself will not cause starting issues.

 

[MMartin401]

Just FYI a Vortec will run without a cam sensor all day long. A cam sensor itself will not cause starting issues.

THANKS AGAIN, ENJOY YOUR EVENING/WEEK!!

 

[someotherguy]

98 CHEVY K1500 5.7 VORTEC WON'T START!! THOUGHTS/INPUT PLEASE!! I HAVE A P1345 CODE, CRANK/CAM SENSORS MISMATCH. I WAS TOLD TO CHECK SPARK AS PART OF THE PRELIMINARY DIAGNOSIS.

The P1345 is very common with the Vortec engines, because of two reasons: distributor wear, and incorrect setting procedure (usually none at all) when replacing the distributor, usually after intake gasket replacement which is super common on the small block Vortecs. The correct procedure is described many times here in the forum and I believe should be a subject of a sticky post.

Back to it though the code for cam/crank correlation isn't what is causing your no-start.

Check spark, absolutely, as you need to confirm it's got good spark.

Check fuel pressure, absolutely, because the small block Vortec often won't even start if the fuel pressure is even a little bit low. Spec is 58-62 psi and it's easy to check right there at the test gauge port on top of the engine.

Cover those two bases and we'll know a lot more.

Richard

 

[MMartin401]

The P1345 is very common with the Vortec engines, because of two reasons: distributor wear, and incorrect setting procedure (usually none at all) when replacing the distributor, usually after intake gasket replacement which is super common on the small block Vortecs. The correct procedure is described many times here in the forum and I believe should be a subject of a sticky post.

Back to it though the code for cam/crank correlation isn't what is causing your no-start.

Check spark, absolutely, as you need to confirm it's got good spark.

Check fuel pressure, absolutely, because the small block Vortec often won't even start if the fuel pressure is even a little bit low. Spec is 58-62 psi and it's easy to check right there at the test gauge port on top of the engine.

Cover those two bases and we'll know a lot more.

Richard

THANKS RICHARD!! I REALLY APPRECIATE THE INFO! I FINALLY CHECKED SPARK ON #1 SPARK PLUG WIRE AND IT SEEMS GOOD WITH A CHEAP IN-LINE TESTER PLUS RIGGED XTRA LEAD SO I COULD SEE IT WAS GETTING SPARK. WHEN I DID THAT TODAY, IT BACKFIRED. I ALSO TESTED THE FUEL PUMP RELAY AND IT IS GOOD. I'LL CHECK FUEL PRESENCE/PRESSURE NEXT AS YOU RECOMMENDED. PLEASE CORRECT ME IF I AM WRONG, BUT THE TIMING CHAIN IS NOT BROKEN. IS THAT CORRECT? COULD THE CRANKSHAFT POSITION SENSOR BE DEFECTIVE OR DOES THE PRESENCE OF SPARK INDICATE THAT SENSOR IS WORKING? I APPRECIATE ALL YOUR HELP!! ENJOY YOUR EVENING/WEEKEND!! BE SAFE!

 

[L31MaxExpress]

THANKS RICHARD!! I REALLY APPRECIATE THE INFO! I FINALLY CHECKED SPARK ON #1 SPARK PLUG WIRE AND IT SEEMS GOOD WITH A CHEAP IN-LINE TESTER PLUS RIGGED XTRA LEAD SO I COULD SEE IT WAS GETTING SPARK. WHEN I DID THAT TODAY, IT BACKFIRED. I ALSO TESTED THE FUEL PUMP RELAY AND IT IS GOOD. I'LL CHECK FUEL PRESENCE/PRESSURE NEXT AS YOU RECOMMENDED. PLEASE CORRECT ME IF I AM WRONG, BUT THE TIMING CHAIN IS NOT BROKEN. IS THAT CORRECT? COULD THE CRANKSHAFT POSITION SENSOR BE DEFECTIVE OR DOES THE PRESENCE OF SPARK INDICATE THAT SENSOR IS WORKING? I APPRECIATE ALL YOUR HELP!! ENJOY YOUR EVENING/WEEKEND!! BE SAFE!

There is actually a GM TSB for the crank sensor causing a plethora of problems, including no start and backfiring.