I have '94 5.0 that revs up to ~1500 rpm on start up then the check engine light flashes for a few seconds then the the rpms drop really low around ~300 rpm then either dies or goes back up to ~1500 rpm and runs fine with no check engine light. This only happens occasionally when it is cold out. It happened yesterday when it was 20 degrees out and died and on the second start up there was no check engine light and ran normal. In the past it would only happen if the the heat was on but the thermostat was set on off it wouldn't happen. What could be causing this?

 

Clean the IAC & run Error code scans. Seafoam, as directed. Skip adding to the oil unless changing to oil soon.

 

what is the iac?

 

http://fordfuelinjection.com/?p=39

 

You should do a forum search, cause pretty much everyone who is on this forum has had to do it at some time I'm sure. But its the Idle Air Control valve. I'm not sure of the exact location on the 5.0, but its bolted to the top of my throttle body on my 4.9 right above where the throttle is located. That valve gets built up with gunk and residue and the valve gets 'sticky' and cause the idle to fluctuate. I cleaned mine with electric parts cleaner, because its what I had, or you can use throttle body cleaner. Just dont use wd-40 or anything that leaves a residue or you'll be doing this again in a few miles.

 

Aw you beat me. And the link was a good idea, thats a lot quicker than explaining it haha

 

Ya, the SOS is staring to get to me! Good Morning!

 

Haha at least the same old is consistent. And good morning! Nothing like wandering around the forum to kill some morning hours at work...

 

It's a dirty job , but...............