v10 excursion with problems!!!!:(

[whiteexc22]

hey guys i need some help in a bad way...my excursion had been to 4 shops and has been sitting for 7 months now...when you drive the thing and pull up to a stop light or a stop sign and prepare to stop and when you do stop the motor lugs down to around 400 rpm and wants to stall and sometimes does and when you pull away it shifts down to first,so its like it stays in second while your on the break and when you let off the brake pedal and start to roll it shifts down...it also at an idle in park stalls and misses every once in a while...sounds like a machine gun sound at an idle....iac has been changed,,,maf has been changed,,,cops have been changed,,,,speed sensors have been changed.....check engine light is on but registering no codes? tranny shop ran the tranny for codes but came up with nothing....im at wits end trying to fig this out...could it be the main computer? i dunno whats left so hopefully someone out here can help

[wallz]

Have you tried looking at your main fuse board, and gem. I think they are generally in the same area. This model cab is VERY well known for bad windshield install and having leaks that run down into the fuse area and screw around with electronics, which sounds like what your having. I would start by taking off the cover on the pillar and looking for water marks in the dust on the inside of the cover, and then further under the dash. I think if you do a search for gem module in the superduty forum you will bring up the issues that people have run into. I remember reading one just not long ago.

[manglass]

I don't know anything specifically that could be wrong with your Ex but Wallz information above is certainly good as one source of a problem w/o fault codes is often the ECM. In fact, I think it's impossible (under normal circumstances) to set the check engine light w/o a fault code. I would certainly look at the ECM as a suspect.

The other common possibility is something mechanical. Don't know what that would be but you can always start with a compression test.

Lou Manglass

[Diamond-X]

ECM may infact be your problem, reset it by disconnecting the battery for a few minutes, then reconnect and test drive.

However, your description of pulling up to a stop light and the engine lugging sounds like a transmission problem. It sounds like the trans is fighting the engine and locked in second.

If I was a betting man I would say your engine is fine. Try popping it into neutral prior to starting your braking for the light.

Keep us posted .