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2008 corvette with LS3 engine, stock.
replaced plugs and coil packs on all cylinders
#2 cylinder is having an issue
i put an inline spark tester on #2 started car and it did not show any spark
did same test on #6 and it showed spark
switched coil packs on 2 and 6
Started car, and placed tester on #6 and it showed spark
placed tester on #2 and it showed spark
took tester out and started car drove around block got a check engine light
code was P0302
checked with in line tester, getting no spark
If you have all new coil packs and you still have no spark on #2 did you check the wiring on the #2 coil pack ??…you said you swapped coil packs between 2 and 6 and you showed spark on both so I don’t know if you meant no spark on #2 ??…if wiring is bad you can change 100 new coil packs and it still won’t work and you NEVER assume the wiring is good…coil packs rarely go bad…these are 4 wire coil packs…do you have a DVOM and 12 volt test light ??…pink is 12 volts, red is control from ECM, black is ground and brown is a low reference or an ECM ground…12 volt power, low reference and ground are all shared on bank #2.
I switched the coil packs to test if the problem followed the pack. The problem did not follow the pack, but the strange thing was #2 cylinder showed spark with a different pack. So I drove the car around the block and the issue came back on cylinder 2. No spark was coming from the pack. So I think we are in agreement that I have a bad wire?
OK, first you will also need a 12 volt test light to check ground…when you have the coil pack connector disconnected and with the ignition in “run” (hold the bottom of the start switch down for 5 seconds until the green light illuminates)…probe the PINK wire and you should see system voltage…now take your test light and connect to battery POSITIVE…touch the tip of the test light to the black and brown wires (low reference and ground)…test light should illuminate on both…DON’T shove the tip of the test light or DVOM lead into the connector because you may spread the terminal apart and have more issues…I use a back probe and if you have a safety pin or a needle use that…if you go to a craft store you can get a box of T pins and use that…the last test is for control on the RED wire…plug the connector back in and gently run the T pin or safety pin down the wire until it bottoms out…on a good control wire you will see a digital square wave of 4-5 volts with a labscope…with a DVOM you will see the voltage fluctuate between 0-0.2 volts…see the video….thats all 4 wires !!
First thank you thank you for the drawing and video.
I am going to perform the tests today’s
If you have NO control on the red wire at the coil pack remove the connector between the coil packs and check for continuity between the pin pictured and the coil pack red wire.
Okay
probed the ground and test light went bright, so ground is good
probed the pink and I was getting voltage
started car to probe the red. Warnings no longer being posted, car running smooth
probed red anyway and got between .1 and .2 volts
drive the car for about 5 miles, got on highway and off
Engine light posted on way home
cecked OBD error:P0302 misfire
repeated test got ground
and got voltage on both red and pink
going to let car cool down and check in line spark again
When you say "and got voltage on both red and pink". do you mean that the test with the code present was the same result as when no code was present? I mean, red (.1-.2) and pink (I assume 12v) with and without the code/CEL?
If this is an intermittent open, which it could possibly be, the CEL would normally not clear that quickly???
Went to repeat test
grounding tests passed
started car and check engine light was not on
ehile car was running, I pulled the connector on cylinder 2 coil pack
probes red line and got between 0 and .2 colts (meter set at 20)
probed pink line and got 13.75 volts
Here are pics of my connection to the coil pack. It is different from yours
My car is a basically stock ‘08 LS3 but looks like your coil pack you purchased are aftermarket…here is a picture of my connector….pink, red, brown, black…I’d put your old coil pack on an retest…while you are taking these measurements with voltmeter or test light shake the harness down while testing…if I suspect a wiring issue I pierce the wire because if you use a back probe and I don’t know if you did this can sometimes restore a bad connection.
I will go jiggle the line. Based off your earlier emails I bought a back probe set. Figured it was a good investment
so all of my measurements are with back probes
I will go jiggle the line. Based off your earlier emails I bought a back probe set. Figured it was a good investment
so all of my measurements are with back probes
T pins purchased at a craft store would work too…if you are going to purchase back probes you should purchase some piercing probes…I use Pomona which can be purchased on Amazon…they are expensive but the BEST !!
2008 engine misfire
