Hey to all. Following is my problem. Thanks to all in advance for any help.
The check engine light was on. According to my HP Tuners Scanner the code was P0306. I pulled all the plugs and did a compression check. The lowest was 150 and the highest (cylinder 6) was 170. Since the code refers to cylinder 6, and it had the highest compression, I continued troubleshooting.
Firing order was correct
I put the plug in a different hole. No difference (side note: all plugs were installed brand new a month ago. They all still look brand new except 6 which is pretty black)
I swapped plug wires with a different one. No difference
I swapped #2 and #6 wires at the coil. No difference
I unplugged coil and turned it over several times. Pulled #5 and #6 plugs to compare. Neither were wet, which I found odd, but the engine was still pretty warm so I thought maybe the fuel on the plug(s) may have evaporated while I was removing it. Since they were the same, I moved on.
I then began to look at the injector which is new, by the way. We changed that a few weeks back trying to get rid of the code.
I noticed this time that the plug for the injector was not OEM. Both wires were black and were SOLIDLY spliced onto the factory wires. I had no doubts about the splices being good, but I thought maybe the metri pack end might have a problem. I got a new one and put it on.
I put everything back together and cleared the code. The light did not come back on (and still hasn’t).
So we took it for a drive. Seemed to do well until about 5 minutes into the drive. The light began to flash. At any time the light flashes, if you give it any throttle, it does the stumbling with zero power thing. It seems that if you get on and off the throttle, it helps it clear up, but that may be my imagination. This always seems to happen when coming out of a dead stop, but will occasionally do it while driving at speed but that is rare.
I came back and hooked the laptop back up to it. It showed no codes. I’m guessing that is because the light wasn’t staying on? I did notice there was a PID I was monitoring called Fuel System #1 Status (SAE). When it was running right, that PID would read CL-Normal and when it would mess up and the light would flash, it would read OL-Fault. I can only assume the CL/OL is open loop/closed loop. If you sat and watched it for a bit you would notice the light would flash and then go away, then come back, etc. So I began paying attention to that. I opened the TPS to 20% and kept it there. The Fuel System Status would go to CL-Normal for exactly 15 seconds, then go to OL-Fault for 30 seconds and then back, etc… Maybe the intervals would be different at a different TPS%, but that was at 20%. The flashing check engine light corresponded with the OL-Fault. The problem is I don’t what that OL-Fault even means nor do I know if it is the cause or effect of something else. Unfortunately, I can’t read the PCM piece that tells me what takes in and out of closed loop. (not supported by HP Tuners)
Somewhere in the middle of all this, I did a driving test with the fuel pressure gauge hooked up. It maintained 65psi the whole time, even when it was “messing up”.
I also cleaned the MAF with MAF cleaner as well as cleaned the throttle body.
The check engine light never did come back on steady and stay on. However, I show DTC of P0306 (pending).
All I know to do now is get a gallon of gas and a match, but it has now become a personal challenge. I’m hoping someone else finds it a challenge as well because I’m running out of ideas. Maybe new PCM?
The check engine light was on. According to my HP Tuners Scanner the code was P0306. I pulled all the plugs and did a compression check. The lowest was 150 and the highest (cylinder 6) was 170. Since the code refers to cylinder 6, and it had the highest compression, I continued troubleshooting.
Firing order was correct
I put the plug in a different hole. No difference (side note: all plugs were installed brand new a month ago. They all still look brand new except 6 which is pretty black)
I swapped plug wires with a different one. No difference
I swapped #2 and #6 wires at the coil. No difference
I unplugged coil and turned it over several times. Pulled #5 and #6 plugs to compare. Neither were wet, which I found odd, but the engine was still pretty warm so I thought maybe the fuel on the plug(s) may have evaporated while I was removing it. Since they were the same, I moved on.
I then began to look at the injector which is new, by the way. We changed that a few weeks back trying to get rid of the code.
I noticed this time that the plug for the injector was not OEM. Both wires were black and were SOLIDLY spliced onto the factory wires. I had no doubts about the splices being good, but I thought maybe the metri pack end might have a problem. I got a new one and put it on.
I put everything back together and cleared the code. The light did not come back on (and still hasn’t).
So we took it for a drive. Seemed to do well until about 5 minutes into the drive. The light began to flash. At any time the light flashes, if you give it any throttle, it does the stumbling with zero power thing. It seems that if you get on and off the throttle, it helps it clear up, but that may be my imagination. This always seems to happen when coming out of a dead stop, but will occasionally do it while driving at speed but that is rare.
I came back and hooked the laptop back up to it. It showed no codes. I’m guessing that is because the light wasn’t staying on? I did notice there was a PID I was monitoring called Fuel System #1 Status (SAE). When it was running right, that PID would read CL-Normal and when it would mess up and the light would flash, it would read OL-Fault. I can only assume the CL/OL is open loop/closed loop. If you sat and watched it for a bit you would notice the light would flash and then go away, then come back, etc. So I began paying attention to that. I opened the TPS to 20% and kept it there. The Fuel System Status would go to CL-Normal for exactly 15 seconds, then go to OL-Fault for 30 seconds and then back, etc… Maybe the intervals would be different at a different TPS%, but that was at 20%. The flashing check engine light corresponded with the OL-Fault. The problem is I don’t what that OL-Fault even means nor do I know if it is the cause or effect of something else. Unfortunately, I can’t read the PCM piece that tells me what takes in and out of closed loop. (not supported by HP Tuners)
Somewhere in the middle of all this, I did a driving test with the fuel pressure gauge hooked up. It maintained 65psi the whole time, even when it was “messing up”.
I also cleaned the MAF with MAF cleaner as well as cleaned the throttle body.
The check engine light never did come back on steady and stay on. However, I show DTC of P0306 (pending).
All I know to do now is get a gallon of gas and a match, but it has now become a personal challenge. I’m hoping someone else finds it a challenge as well because I’m running out of ideas. Maybe new PCM?