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1997 Chev Blazer 4.3


Debschrysler
12-09-2008, 08:22 AM
Hey I could use some serious help before I go broke.
I have a 1997 Chev Blazer 4.3 with a radomn misfire on cylinders 1,3,5.
I have changed plugs, cap,rotor,wires. The mechanics working on my vehicle say they have tried everything. Check fuel pressure, oxygen sensor, exhaust.everything.
Any ideas would be great.:banghead:

old_master
12-09-2008, 09:18 PM
Random misfire is almost always caused by secondary ignition. This includes distributor cap, distributor rotor, spark plug wires, spark plugs, and ignition coil. These engines are very fussy when it comes spark plugs, use AC Delco ONLY.

Low fuel pressure can also cause any P0300 series DTC to set along with lean oxygen sensor DTC's. Key on, engine off, fuel pump running, fuel pressure must be 60psi to 66psi. After the fuel pump shuts off, fuel pressure must remain above 55psi for 3 to 5 minutes. Post the results and we can help more if needed.

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