This car had high misfire counts and basically would only miss at idle, like a vacuum leak , or dirty fuel injector , another shop already had changed coil pack, plugs , and ignition module. No fuel injector balance test was available on either Port Freight 08 or my Snap On Brick that covers 2005 MY
Because it has a coil pack assembly and not separate coils with short wires (like The 5.3 L I last tested compression).Was unable to get the awesome bar graph Cranking Amps test feature on my ancient Counselor 2 to work.There was no relay or fuse in the engine compartment fuse box Labeled fuel pump to remove and disable it's fuel pump quickly ,so I had to resort to the Clear Flood WOT method to prevent engine starting which ruined my plan of using #1 fuel injector pulse as a trigger.I had to select lab scope and set to 1volt and 100MS (still using High amp probe). I compared the humps and noticed that one wasn't as high as the rest. Knowing that I had a missfire code for #1 with high miss fire counts history, I confirmed my hunch that the cylinder attributed to the smaller hump would be #1. I confirmed only 120psi with a compression gauge. I pulled out cylinder 4 plug also and confirmed at least 190psi. Knowing both cylinders reach TDC together I put a long thin bladed screw driver down #1 spark plug hole and the long screw drive measured at the same height as down #4 from the piston crown , so I knew the #1 rod was still straight. Cylinder leakage test on #1 confirmed there was high leakage past the exhaust valves. Looks like another low mileage GM be getting a new set of 8 exhaust valves. Customer said it did once get hot when the radiator went out 5 years ago, but hasn't had any overheat issues since.He was driving it around with a wrong air filter that was too small for the air box, but no piston ring sealing issues yet
Seems to me with today's Hi tech capabilities that the expensive new Verus Edge doesn't offer the feature of a nice bar graph display for relative compression test like the Ancient Counselor, Ford SBDS, WDS, and IDS offers. Guess for 10 grand you still Gotta Hump it.
Because it has a coil pack assembly and not separate coils with short wires (like The 5.3 L I last tested compression).Was unable to get the awesome bar graph Cranking Amps test feature on my ancient Counselor 2 to work.There was no relay or fuse in the engine compartment fuse box Labeled fuel pump to remove and disable it's fuel pump quickly ,so I had to resort to the Clear Flood WOT method to prevent engine starting which ruined my plan of using #1 fuel injector pulse as a trigger.I had to select lab scope and set to 1volt and 100MS (still using High amp probe). I compared the humps and noticed that one wasn't as high as the rest. Knowing that I had a missfire code for #1 with high miss fire counts history, I confirmed my hunch that the cylinder attributed to the smaller hump would be #1. I confirmed only 120psi with a compression gauge. I pulled out cylinder 4 plug also and confirmed at least 190psi. Knowing both cylinders reach TDC together I put a long thin bladed screw driver down #1 spark plug hole and the long screw drive measured at the same height as down #4 from the piston crown , so I knew the #1 rod was still straight. Cylinder leakage test on #1 confirmed there was high leakage past the exhaust valves. Looks like another low mileage GM be getting a new set of 8 exhaust valves. Customer said it did once get hot when the radiator went out 5 years ago, but hasn't had any overheat issues since.He was driving it around with a wrong air filter that was too small for the air box, but no piston ring sealing issues yet
Seems to me with today's Hi tech capabilities that the expensive new Verus Edge doesn't offer the feature of a nice bar graph display for relative compression test like the Ancient Counselor, Ford SBDS, WDS, and IDS offers. Guess for 10 grand you still Gotta Hump it.
Comment