Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

"Misfire on 5"

96 Chevy express 1500 V8-305. Have a P0305 code…Misfire on 5. Let me tell you everything I have done so nobody wastes their time.

I have, replaced the entire ignition system, “EVERYTHING” including a new distributor…Not the problem… I did a compression test…Not the problem…injector cleaning…not the problem.

When I moved the wire harness that goes into the “spyder” fuel injector system the engine smoothed out. I untaped the harness from around the plug and applied pressure to each wire the engine smoothed out. The back row 2nd pink wire seems to cause the most reaction.

My question is…Is it the wire harness or is it the injector system not reading plug? or could it be a combination of the 2? If I replace the wire harness might I still have to replace the injector system?

If moving/touching the wires solves the problem, then the problem is most likely the connection at one end of the wire. Wires seldom break in the middle, it can happen but it is rare. It usually happens at the connector.

It can be the connector itself, that is the pin might have some corrosion on it or has lost its “spring” or tension that holds the contact, or the wire has frayed where it is crimped to the connector. If it is a frayed wire, or if the female part of the connector is in the harness, then replacing the harness should fix it. If the female part of the connector is in the injector, then the injector will need to be replaced.