2003 E350 Plugs/COP

[95astroman]

What's the quickest and easiest way to check and change the plugs and COP? I'm getting misfire upon acceleration. Van has 145K miles

[danielsatur]

1) Are you getting misfires on a single cylinder, or random misfires on all cylinders?
2) How many miles are on the plugs?

[95astroman]

The plugs have about 25K on them. Seems to misfire on accelerating more on hot days and higher altitudes. Occasionally get a "check engine light" but it goes away when driving easy at 55 mph on level ground. I can't tell which cyl or how many. Starts and idles just fine. I would like to pull one plug just to see...Can't see plugs without removing stuff....which plug is the easiest to get to?

[danielsatur]

Plugs are usually good for 100K miles, and we only replace COP's as needed.
1) Clean air filter
2) Clean MAF/IACT sensors.
3) Replace fuel filter.
4) Check fuel pressure.

Do a Google ''Youtube Auto how to clean a MAF sensor''

How's the fuel economy?
It might be time for new upstream H02 sensors too, if over 100K miles.

[95astroman]

Thanks for the detailed info. How do I clean MAF/IACT sensors and where are they.
Should I be able to see a spark arcing if the coil or plug is bad?

[danielsatur]

The MAF/IACT sensors are in the air duct, it's inbetween the air filter box and the throttle body, look for the electrical connection.

See COP Test, http://www.automotiveforums.com/vbul...d.php?t=906504

The best price for COP's are probably on www.ebay.com