xxfonziexx
New Member
- Joined
- January 11, 2010
- Messages
- 4
- Reaction score
- 0
- City, State
- NY
- Year, Model & Trim Level
- 99 Mountaineer AWD
Hi,
I'm new here, but I could really use some advice. I have a '99 Mountaineer 5.0 AWD with a misfire problem. It's always cylinder 1 (code 0301), and occasionally I've gotten a "bank one too lean" code out of it too. I suspect that might have been a result of the misfiring cylinder (1/4th of that cylinder bank isn't burning anything, so there's 25% more air coming out of the exhaust than there should be).
Here's what I've done so far: New plugs and wires, no change. It didn't make much sense, but new coil pack with no change. Checked that the plug was sparking and it looked was, and it's a good strong spark because I got my hand a little too close to the plug end of the wire when I had it off and it zapped me from a distance.
I decided it probably wasn't a spark issue and moved on to fuel. I replaced the fuel injector in cylinder one with no change, and then pulled the battery to make it forget it's fuel trim with no change.
Fuel pressure is around 60 psi off, a few psi lower while running. Compression check of cylinder one matched a couple of other cylinders almost exactly (didn't bother to check them all). Vacuum is steady around ... 18 inches of mercury maybe? Can't remember the number now. Drops down sharply when gas is hit and then comes back up. Almost no fluctuation while running.
The engine seems fine mechanically, it's sparking good and strong, and it has a new fuel injector. What could possibly be left that would make only one cylinder misfire?
I'm going to drop a new fuel filter in it tonight after work (can't see any reason for it to change anything thought). The only other thing I can think of is an electrical problem in that injector circuit. I'm going to see if I can hear it firing with a stethoscope tonight, and pull the connector and stick a mulitmeter into it if I can't.
Assuming it's being triggered, can anyone recomend a next step? I'm seriously frustrated at this point.
I'm new here, but I could really use some advice. I have a '99 Mountaineer 5.0 AWD with a misfire problem. It's always cylinder 1 (code 0301), and occasionally I've gotten a "bank one too lean" code out of it too. I suspect that might have been a result of the misfiring cylinder (1/4th of that cylinder bank isn't burning anything, so there's 25% more air coming out of the exhaust than there should be).
Here's what I've done so far: New plugs and wires, no change. It didn't make much sense, but new coil pack with no change. Checked that the plug was sparking and it looked was, and it's a good strong spark because I got my hand a little too close to the plug end of the wire when I had it off and it zapped me from a distance.
I decided it probably wasn't a spark issue and moved on to fuel. I replaced the fuel injector in cylinder one with no change, and then pulled the battery to make it forget it's fuel trim with no change.
Fuel pressure is around 60 psi off, a few psi lower while running. Compression check of cylinder one matched a couple of other cylinders almost exactly (didn't bother to check them all). Vacuum is steady around ... 18 inches of mercury maybe? Can't remember the number now. Drops down sharply when gas is hit and then comes back up. Almost no fluctuation while running.
The engine seems fine mechanically, it's sparking good and strong, and it has a new fuel injector. What could possibly be left that would make only one cylinder misfire?
I'm going to drop a new fuel filter in it tonight after work (can't see any reason for it to change anything thought). The only other thing I can think of is an electrical problem in that injector circuit. I'm going to see if I can hear it firing with a stethoscope tonight, and pull the connector and stick a mulitmeter into it if I can't.
Assuming it's being triggered, can anyone recomend a next step? I'm seriously frustrated at this point.
I even tried a second new plug and another plug wire.
