Search the Community
Showing results for tags 'strange spark frequency'.
Found 1 result
-
Hi everyone. I am a newby here, but have been trying to get onto the site for months. Each time it came up in a google search, the return timed out and I couldn't get a page open. So, hopefully, I can get back on to read the responses to my question, but just a heads up that it might take some time to respond or even read any answers. So, here is the question. I have a 2006 Outback that I bought for my son. It had blown the head gasket on the left hand bank some time ago, and also had a frozen thermostat which locked all the heat into the left hand bank. The previous owner was not very savvie, and used some silver seal to attemp a fix. I have no idea how long he drove it for with the locked themostat, but it had pushed the valve guides down on the exhaust stems, and they were quite carboned up so I would say it was a while. Anyway, I bought a 2004 wreck for spares, and after getting the '06 apart, found the block to have softened, so took the block and left hand head off the '04, changed the camshaft over, re-seated the valves, and put the entire thing back together, using the '06 cam and crank gears. I also had to advance the valve timing, as I was a little over-zealous with the sander when I cleaned the heads. I had just done the head gaskets on my daughter's '07 Forester, which had a performance exhaust, and had the valve timing 6 teeth advanced, and it runs just fine!!! This '06 was running fine before the head work, but now shows a very strange fault. It is firing the coil on numbers 2 and 4 at around twice the rate it should be. I can see this with a timing light. 1 and 3 are sparking in sync with the engine sounds, but 2 and 4 seem to be operating at about double the speed. The only thing I did that I probably shouldn't have, was that I broke off one of the teeth from the crank wheel when I was removing it. I have glued it back in place with some epoxy metal filler. Can't remember the name of it off hand, but I tried to get it to move towards a strong magnet while it was wet, and it didn't move, so I assumed it was non-magnetic...(I know JBWeld ismagnetic). It is running very rough at idle, pops and farts when cold, stutters and hesitates down low, but launches at around 3000 rpm as it should. We have checked the coil pack connection, and re-fit the main loom plug a few times, as well as checked the leads to make sure they are all pushed onto the plugs properly. What could be causing the high spark frequency??? How would it even be possible?? I have not put a scope on the crank sender, to check for a frequency match with the power leads to the coils, but that is next if no-one has any solutions. It is the only thing that could be causing the issue, as the cam only has four lobes to trip the sender. What causes the coil to stop firing??? Is it ECU magic?? Why would it be both 2 and 4?? The initial test drive was done without a front AFR sensor on the vehicle, and it was moved a few times without either the O2 or AFR sensor connected, but I don't think this would have killed the ECU. Any help will be smiled upon. Thanks.