Simple testing screwed up the car.
Simple testing screwed up the car. I dont know what the hell I did, but a ran a few simple tests on my fuel system and by the end of the night I ended up throwing a p303 (engine mis-fire). It's very noticable at idle, and at throttle. The SES light will flash at my constantly if I run the car over 25mph for any amount of time. Here is everything I did:
1998 Camaro Z28 M6
Fuel Injection System Pressure Test
KOEO: 57psi
KOER: 58psi
WOT with regulator attached: 57psi
Pressure held after 15 minutes of engine shut down.
Scoping a fuel injector (cylinder #1)
Injector on time: 2ms
Ontime varied at idle slightly.
Injector on time at 2000rpm: 2ms
Ontime did not vary.
Peak on time with throttle snap: 14ms
Voltage spike: 60v
Fuel volatility and Alcohol content test.
No evidence of water in fuel.
Very small evidence of sediment in fuel.
8% alcohol content.
.758 specific gravity at 90degrees (spec is .716 max for normal range)
*Gas from BP in Denver, Colorado. (mile high in alt.)
Fuel Injector and Air Intake cleaning (attemted)
Checked throttle blades for deposists. Checked out ok.
No noticable vacuum leaks.
Engine mechanically sound.
No codes in the computer (at this time)
Ignition functioning properly.
Removed fuel pump fuse to disable fuel pump.
Hooked up the BG cleaning tool to the shcrader valve, cranked the engine with a no start. Replaced fuse to check for leaks, cranked again and found a major leak at the schrader valve. Removed tool and cleaned up.
Didnt have time to finished the cleaning, didnt add any of the cleaning liquids into the tool.
With that all being what I did, what could I have done to get a misfire of this magnatude? On the scoping of an injector, I did at first connect my leads in series, negative to the green with black strip wire and the positive to the pinkish wire, then switched them around, and then finally grounded on the chassis and positive lead to the green wire to get the results that I have. Im not sure if connecting it in series couldve screwed anything up, seeing as I got a good waveform after the fact. I didnt disconnect any vacuum hoses, the only thing I really took off was the negative to the battery, and everything on the intake from the LID to the front of the throttle plates. Checked the fuel pump fuse just in case, it's good and where its suppose to be. The fuel system passed all of the tests except the fuel specific gravity, but that wouldnt cause a sudden misfire like this as I have been using this fuel for the past few months.
Any idea where I went wrong or what to check? Any help is very appreciated!
1998 Camaro Z28 M6
Fuel Injection System Pressure Test
KOEO: 57psi
KOER: 58psi
WOT with regulator attached: 57psi
Pressure held after 15 minutes of engine shut down.
Scoping a fuel injector (cylinder #1)
Injector on time: 2ms
Ontime varied at idle slightly.
Injector on time at 2000rpm: 2ms
Ontime did not vary.
Peak on time with throttle snap: 14ms
Voltage spike: 60v
Fuel volatility and Alcohol content test.
No evidence of water in fuel.
Very small evidence of sediment in fuel.
8% alcohol content.
.758 specific gravity at 90degrees (spec is .716 max for normal range)
*Gas from BP in Denver, Colorado. (mile high in alt.)
Fuel Injector and Air Intake cleaning (attemted)
Checked throttle blades for deposists. Checked out ok.
No noticable vacuum leaks.
Engine mechanically sound.
No codes in the computer (at this time)
Ignition functioning properly.
Removed fuel pump fuse to disable fuel pump.
Hooked up the BG cleaning tool to the shcrader valve, cranked the engine with a no start. Replaced fuse to check for leaks, cranked again and found a major leak at the schrader valve. Removed tool and cleaned up.
Didnt have time to finished the cleaning, didnt add any of the cleaning liquids into the tool.
With that all being what I did, what could I have done to get a misfire of this magnatude? On the scoping of an injector, I did at first connect my leads in series, negative to the green with black strip wire and the positive to the pinkish wire, then switched them around, and then finally grounded on the chassis and positive lead to the green wire to get the results that I have. Im not sure if connecting it in series couldve screwed anything up, seeing as I got a good waveform after the fact. I didnt disconnect any vacuum hoses, the only thing I really took off was the negative to the battery, and everything on the intake from the LID to the front of the throttle plates. Checked the fuel pump fuse just in case, it's good and where its suppose to be. The fuel system passed all of the tests except the fuel specific gravity, but that wouldnt cause a sudden misfire like this as I have been using this fuel for the past few months.
Any idea where I went wrong or what to check? Any help is very appreciated!
I did a voltage test on it KOEO, showed 11.97 at the injector with a battery voltage of 12.09.
Checked the resistance on cylinder #1-3. Figured out that P303 indicates a mis on cylinder 3.
Resistance results:
#3: 11.8ohms
#2: 12.2ohms
#1: 12ohms
Checked the resistance on cylinder #1-3. Figured out that P303 indicates a mis on cylinder 3.
Resistance results:
#3: 11.8ohms
#2: 12.2ohms
#1: 12ohms
