Engine will not start after overheating and shutting off

INDEGO77

MEMBER
2000 CHEVROLET BLAZER
4.3L
V6
4WD
AUTOMATIC
232,000 MILES

I have the vehicle listed above Ls model. It is not starting. It overheated and shut down. I have checked for white smoke when it was running, there was none. I have checked fluids like oil and transmission for discoloration, there was none. I have changed fuel filter alternator thermostat all spark plugs and wires. Distributor and rotor cap.
It sparks and cranks. It will not turn over
I tested pressure on the number one plug, and it was at 0-2PSI this seems strange
I have been told it could be a head gasket, but it does not show any symptoms not a drop is leaking. Before I go tearing this engine down what could be wrong other than a loan head gasket.

3 Replies

SQM

MECHANIC
6,383 POSTS

Hello,

Have you checked the compression for any other cylinder?
Blown head gasket can impact the compression of the engine, but as you know typically there are other symptoms with it.
If the compression is low for all the cylinders, then head gasket likely the issue.

https://www.2carpros.com/articles/the-reasons-for-low-compression

Let me know what you find on other cylinder compression.
Thank you.

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Wednesday, November 10th, 2021 AT 2:20 PM

INDEGO77

MEMBER
2 POSTS

I've checked all the symptoms for a bad head gasket and thankfully it does not indicate that I have noticed it sparks and cranks. I've changed coolant sensor and MAP sensor as well as fuel filters and test for fuel pressure, which is there I've just checked the fuse box under the hood and the ECM1 has power but the ECMb and ingc do not. Could those two fuses keep it from starting and how do you fix?

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Sunday, November 14th, 2021 AT 9:58 AM

SQM

MECHANIC
6,383 POSTS

Not having power to the fuse could mean wiring issue. Does the connector look clean and corrosion free?
However, that won't make it have low compression.

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Tuesday, November 16th, 2021 AT 2:30 PM