curses. it seems to be one problem after another with this red devil!

a month or two (when it started getting seriously cold) i was having a hard time keeping the 4.7 running in the morning (or whenever it first started for the day). for the first couple of blocks i would drive it would die at every stop sign or light. after a few blocks it would be good to go for the rest of the day.

searching here i found that this was usually related to a battery on it's way out so i had mine checked (along with the alternator) at autozone. everything checks out.

starting about week ago, now i can't keep it running at all. it doesn't stumble or anything, it just shuts off. driving it around today there were a couple times when it would idle, but it was down around 400rpm and really just wanting to shut down.

any thoughts on what i should check? i hate to spend the $80 for a full diag. it's not throwing any codes at all.

 

Sounds like the famous IAC motor going out.

It's been happening a lot on here lately. Start by cleaning out the IAC port on the back of your TB:
http://www.mediafire.com/?k0742k5tvj1dqxh

 

+1 Clean the Throttle body and IAC.

 

+2. Totally agree.

The 4.7 TB has 2 sensors on the drivers side. The top one is the TPS sensor and the bottom one is the IAC sensor. Remove the TB and throughly clean the inside of the bore, the blade and especially the IAC port. Also clean the tip of the IAC sensor being careful not to push or pull on the tip as you may cause internal damage. Reinstall the cleaned TB and disconnect the negative battery cable for 1-2 minutes. Reconnect the battery cable, start the engine, let it idle (DO NOT REV THE ENGINE) and allow it to come up to operating temp. Switch off the engine, restart and go for a drive.

All you'll need is a can of spray carb cleaner. The TB gasket is rubber and is reusable.

 

i love this forum

i'll try it tomorrow or saturday morning and report back. thank you!

 

could be the IAC, but im still leaning towards a bad battery, these trucks are alot more sensitive than the testers are to a battery on its way out, if its more then 3 years old (4 is the expected life of a car battery iirc) i would just replace the battery for peace of mind.

 

i'll try the IAC in the morning and report back. if this doesn't get it done then i'll go with a new battery. i am sure this battery is very old, and the truck even sat for over a year at one point.

thanks again

 

well i got it fixed, with a marginal improvement. the throttle body and the IAC were extremely gunked up, but cleaning them nicely only helped a little. it still starts and dies in the morning, but is back to not dying at every light, so that is good.

when it doesn't die it idles between about 400 and 900 rpm. it's almost hunting and seeking within this range. weird eh?

 

Did you reset the PCM after reinstalling the the TB?

 

I'm seeming to have a similar problem with my 4.7L. When it sits for more than maybe ten minutes, then it takes about 10 seconds of cranking to start. Sometimes it sets the SES and sometimes it doesn't. I took it to Advance and Autozone and they said it had a miss on cylinder #2. When I first bought it and changed the plugs, cylinders #2 and #3 had never been changed before because of the coolant lines going over the COP's. I replaced the coil on cyl. #2. I don't want to go replacing injectors but I don't know what else to do. Does anybody have a better idea, (i.e. TPS, IAC,). I hope I'm not stuck buying a set of injectors.