apenland01
Well-Known Member
- Joined
- September 11, 2009
- Messages
- 322
- Reaction score
- 22
- City, State
- Tucson AZ
- Year, Model & Trim Level
- 2005 Eddie Bauer V8 4.6L
So, I've been chasing this random misfire since I had the timing chains replaced about a month or so ago.
It is not the plugs or boots, as I just replaced all with new. I swapped COP's to multiple cylinders and the misfire stays on the same cylinders. I swapped plugs and boots to multiple cylinders and the misfire stayed on the same cylinders 4 and 8.
I just did a 1200 mile round trip and the misfire only shows up on an incline at highway speed, more specifically the higher gears and OD, often when I feel it should be shifting. Never happens in town just driving around. During this 1200 mile trip, it happened 10-12 times and the misfire only lasts for about 10 seconds, then begins firing normally again. Everytime it happens the SES light flashes, then either disappears or stays lit for a while, then disappears.
In the middle of this trip, I towed an 18' bass boat with 150hp Mercury, so it wasn't light, probably 3000lbs or so. I hauled it about 40 miles and launched it on a steep ramp 4 times over 2 days. It never misfired. It never acted strangely. It almost acted better pulling the boat, than just running up the freeway. It climbed the steep ramp under load without missing a beat.
I can't imagine it is a fuel injector, as I wouldn't expect it to fail intermittently, and if it did, it would happen in all kinds of situations, not just climbing an incline at highway speeds.
This leaves me with the wire, connector or signal from the computer. It is coding at the 4 and 8 cylinder, so the closest to the firewall on both sides. I'm at a loss and don't want to just start throwing money at this thing chasing this misfire, but I'm at the point I need to do something soon before I cook my cats.
Is there a way to test the PCM/ECM without actually changing it out? I may have to break down and have the dealer look at it to see what is going on.
Strange that it just started on my first road trip after getting the timing chains done.
It is not the plugs or boots, as I just replaced all with new. I swapped COP's to multiple cylinders and the misfire stays on the same cylinders. I swapped plugs and boots to multiple cylinders and the misfire stayed on the same cylinders 4 and 8.
I just did a 1200 mile round trip and the misfire only shows up on an incline at highway speed, more specifically the higher gears and OD, often when I feel it should be shifting. Never happens in town just driving around. During this 1200 mile trip, it happened 10-12 times and the misfire only lasts for about 10 seconds, then begins firing normally again. Everytime it happens the SES light flashes, then either disappears or stays lit for a while, then disappears.
In the middle of this trip, I towed an 18' bass boat with 150hp Mercury, so it wasn't light, probably 3000lbs or so. I hauled it about 40 miles and launched it on a steep ramp 4 times over 2 days. It never misfired. It never acted strangely. It almost acted better pulling the boat, than just running up the freeway. It climbed the steep ramp under load without missing a beat.
I can't imagine it is a fuel injector, as I wouldn't expect it to fail intermittently, and if it did, it would happen in all kinds of situations, not just climbing an incline at highway speeds.
This leaves me with the wire, connector or signal from the computer. It is coding at the 4 and 8 cylinder, so the closest to the firewall on both sides. I'm at a loss and don't want to just start throwing money at this thing chasing this misfire, but I'm at the point I need to do something soon before I cook my cats.
Is there a way to test the PCM/ECM without actually changing it out? I may have to break down and have the dealer look at it to see what is going on.
Strange that it just started on my first road trip after getting the timing chains done.
