I have a 1988 Chevrolet C1500 4.3 V6 i done full tune up on it change the cap and rotor but it still backfire and i got the timing checked on it its 2 degrees off whats making it backfire still.

SOURCE: 1998 chevrolet k1500 pickup 305 a misfire in # 2 cylinder

hi there, if you can feel the misfire at an idle but not at a higher rpm than the fuel pressure regulator is bad im working on one right now that has mifire code and random misfire codes coming up

SOURCE: 98 5.7L chevrolet

Engines don't jump time when they are not running.

Rotor will point to number 1 plug wire with every other rotation of the crank.

Get an auto repair manual to confirm you have plug wires in right order on distributor cap.

Also suggest finding Factory Service Manuals at library to get troubleshooting charts and diagnostics.

SOURCE: 1991 Olds Bravada 4.3 v6 rough idle and backfiring.

Ok guys, let's fix these things here!
Just went through this myself, so do the following:
Go to your local parts store and buy a Haynes Repair Manual.
You need to read the book first, learn how the ECM (Electronic Control Module) works. You'll see that there are alot of sensors and components that make up the fuel emissions bologna.
The nice thing about this system is not only does the ECM control all electrical functions, it also trouble-shoots it's self. When a component or sensor goes out, the ECM stores a code for that event in it's memory. You can use the Haynes Repair Manual to put the ECM into diagnostic mode and thus read any codes present.
So, all that's left is replacing what the EMC tells you too! :) Good Luck!

SOURCE: 1988 Chevrolet K3500, Have replaced distributor,

Pick up a spark tester (it'll cost under 15$) . After installing the tester on one of the 2 rear right or left bank spark plugs, have someone turn the engine over and check for spark. If you have no spark, you could have either a broken timing chain or a broken cam-shaft. The only other minor item you didn't mention with regard to the ignition system was to make sure you have a good hot power source to your distributor. If these things don't work, it might be time to check that the carburetor or throttle body fuel injection (as applicable) is providing fuel.

Dennis Mulford

• 1055 Answers
• Posted on Mar 30, 2009

SOURCE: 1988 chevy pickup 4.3 V6 that has constant backfire

bad dis cap or rotor maby a bad plug wire or valve sticking or out of adjusment