A couple years back these flat landers headed to the Rockies. Once over about 8,000 to 8,500 the engine started missing a fair amount. I chalked it up the altitude for a rig that normally sits at 1,000 and really didn't think much more about it. She's run fine since. It was an unusually warm day in the mountains that day.
We're heading back up to RMNP next month and I started thinking about that again and recalling that it was a little stressful wondering if something was really wrong. Can someone with tech abilities put my mind at ease and confirm that sputtering at high altitude on a warm day isn't unusual for a low land E450?
Many thanks, Dave
What year is your E450?
Carburetor vs Fuel Injection ?
What year is your E450?
Carburetor vs Fuel Injection ?
At the bottom of his post he says it's a 2004. That would be fuel injected.
Ed
Our '04 runs smooth as silk up to at least 11,000' and anything lower. There should be no missing, though reduced power is normal.
Steve
I'm in the Rockies now. With 210k miles I have only one miss every now and then when letting off the gas after a climb. I have new plugs and only replaced a couple of coils. When I get back I'll swap the coil to see if the misfire moves and plug torque to see if it changed. It's not enough to light the check engine light but I watch all cylinders with my OBD scanner
Regarding the misfire situation:
Were you heavily loaded and/or have a toad in tow (Don explains why not to tow @ higher elevations (http://www.lazydazeowners.com/index.php?topic=28802.msg159200#msg159200))?
Did she throw any codes (check engine light)?
Were you between 4K and 5K rpm when pulling grade (iirc, max power should be ~ 4500 rpm)?
I would like to echo Craig...some simple suggestions would be:
Plugs...gap & torque
Wires...check your COP wires make sure none have visual degradation
COPs...you can ohm them out to find out if you have a "weak" one (one whose secondary has a very high resistance) although static resistance checks, in and of themselves, do not always avail a failing COP
MAF...clean it (make sure to use MAF/electronic cleaner not carb cleaner)
Air filter...the easiest & somewhat cheapest
Only suggestions...I'm not a mechanic and don't pretend to be. If you're not familiar or comfortable with some/any of the above items, I would find someone who is.
Another idea is to purchase a scan tool so as to allow you to watch engine parameters in real time. Lastly, and most costly, would be to take it to a stealership and have them run diagnostics on the ecu. It may be that she's not pulling enough timing to prevent predetonation...that's the ecu/barometer's job.
I hope this helps somewhat HUSKERBLUE!
igoslow
Were you heavily loaded and/or have a toad in tow (Don explains why not to tow @ higher elevations)?
Did she throw any codes (check engine light)?
Were you between 4K and 5K rpm when pulling grade (iirc, max power should be ~ 4500 rpm)?
YES!! Forgot to provide this important info. Towing and the engine was screaming. I think we'll unhook and drive the car up separately next month.
We were over 6,000 feet in the Black Hills last year pulling pretty hard and no problems. I think I just overtaxed the old girl near the end of a long, hot day the summer before.
Thanks to all again, what a great group!
-- Dave