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-   -   cold temp pre-warmed at stop engine die (http://www.jeepforum.com/forum/f310/cold-temp-pre-warmed-stop-engine-die-1745026/)

derbartman 10-31-2013 09:56 PM

cold temp pre-warmed at stop engine die
 
cold weather is back, and this morning so was my last winter issue. My Jeep seems to really dislike the cold so much that the first few lights and stop signs will often cause it to die and force a restart unless I hold the break and the gas. After if more warmed up it does ok. Sometimes it starts up pretty much no issue, and sometimes it starts up with some cranking.

Where would I start?

derbartman 10-31-2013 10:18 PM

Should have mentioned - this is the 4.7 v8 ~150k miles

86cj74.2L 10-31-2013 11:37 PM

Have you ever removed the throttle body and cleaned it? If not do so.

Do you have a scanner that reads live data? Its worth going out in the morning with engine cold and turn on ignition and look at what the PCM thinks the engine and throttle body temp are. They should be within 5-10 degrees of each other and should be within the same for ambient temp as well.

derbartman 11-01-2013 12:29 AM

I have some plug in OBD scanners which my phone can read - and some software to read them. Im not sure if Ill be able to get those two temps - but ill try. I have not cleaned the thottle body - Ill look into that.

I guess I should run though my hanes book test on the Idle Air Control valve?

My hanes book mentions idle speed being wrong as possilby causing stalls and to check the VECI label?

86cj74.2L 11-01-2013 01:03 AM

Quote:

Originally Posted by derbartman
I have some plug in OBD scanners which my phone can read - and some software to read them. Im not sure if Ill be able to get those two temps - but ill try. I have not cleaned the thottle body - Ill look into that. I guess I should run though my hanes book test on the Idle Air Control valve? My hanes book mentions idle speed being wrong as possilby causing stalls and to check the VECI label?

There are free downloads of the FSM for the WJ. Put your Hanes manual in the garbage.

Step 1 is remove and clean your throttle body.

Step 2 is use your app on cell phone and look for the engine coolant temp, and the throttle body/ intake temp readouts.

rdkendrick 11-01-2013 09:16 AM

Quote:

Originally Posted by 86cj74.2L (Post 17338370)
There are free downloads of the FSM for the WJ. Put your Hanes manual in the garbage. Step 1 is remove and clean your throttle body. Step 2 is use your app on cell phone and look for the engine coolant temp, and the throttle body/ intake temp readouts.

That's what people on here keep saying, but the only person I have seen to actually provide a link to one is ALFAITALIA and his link is: http://colorado4wheel.com/manuals/Jeep/ but that is only for a 2001. I know a lot of the things are the same, but there are also things like wire colors that are specific to certain years. If you know where the FSM's can be found online, please provide a link.

Since then, more have been posted:

http://pdftown.com/Pdf-eBook/Jeep.html?from=0

http://www.nagca.com/manuals/01/manual01wj.zip

password: techauthority

http://wagoneers.com/WJ/tech/

http://www.the12volt.com/installbay/...eard/Jeep.html

http://pdftown.com/Jeep-PDF-eBook-Category.html

http://colorado4wheel.com/manuals/Jeep/

Sent from my iPad using my fingers

86cj74.2L 11-01-2013 01:18 PM

I googled my brains out one evening and found a download a few years back

Then about 1 year ago I bought a 2004 CD for 15 dollars off EBay.

Pm me your email address.

rdkendrick 11-01-2013 01:23 PM

Quote:

Originally Posted by 86cj74.2L (Post 17348690)
I googled my brains out one evening and found a download a few years back Then about 1 year ago I bought a 2004 CD for 15 dollars off EBay. Pm me your email address.

I have a 2002 FSM that I bought when I had a 2002 Overland. When that got totaled, this FSM pretty much still applies to my 2003 Overland. Thanks for the offer, but I was saying that mostly for the benefit of whoever is reading the post. I searched and search, but could never find the free versions either. People on here keep saying there are free FSM's out there, but never give a link, and I could never find them.

Sent from my iPad using my fingers

derbartman 11-03-2013 02:27 PM

here is what I have so far:
sitting pre start : 15 C for coolant , and 17C for IAT
also we measured the resistance on the idle control device and the pin 1 to 4 vs pin 2 to 3 showed 52.4 vs 52.9 (not 100% sure which was which).

So in both cases the results are not identical, but it seems like they both are fairly close.

We also tried the test of putting the engine under load to see if the idle would adjust - it did seem to initially it would go down, and then up above the initial idle and then down a little when we put it in gear with the break on.
I didn't try AC.

Hopefully just the cleaning will do the trick.

I cleaned out the throttle body - as best I could without removing it.
I didn't get up early enough to try the cold idle issue, but plan to tomorrow.

970001zj 11-03-2013 02:47 PM

odd thought why dont you just warm it up ?

it will give better gas mileage and power along with less wear and tear

86cj74.2L 11-03-2013 03:01 PM

Remove the throttle body to clean it. You also need to remove the IAC from its hole and clean all the crunchies from its pintle

The IAC is a motor. Not a sensor.

derbartman 11-04-2013 10:18 AM

Ok more update - Ill try those recent suggestions also.

So tried this morning in cold. It didn't die like I would have expected, but it still had trouble. Its interesting - it seems fine with accommodating a change in load, but when I come to a stop - at first its idle is fine, and then it will dip down significantly say maybe to 450rpm and then in today's case recover back to 800 or so - this is while it is still not hot, but the temp gauge has started to move. I tired this repeatedly and it was pretty consistent with this post stop fine then big rpm dip then recovery. It wasn't as cold today as in past - so im not 100% sure the throttle body cleaning (without removal) has helped or not, but it didn't die at the stops - it just seemed to try pretty hard.

why not just let it warm up --
well its a v8 takes a while, it shouldn't need to - most of us are pretty used to vehicle just being ready to go (we are talking 30-40 F not -10), its illegal to leave our car running without someone in it, so someone would need to sit in the car for many mins prior to the desired departure time (hard to do with the rush and lateness of kids going to school) -- overall its an admirable idea which doesn't fit for all my household members very well. Im trying to get this jeep running well and liked so that it doesn't get the axe from the over all family vehicle needs. I told them all to just double foot break and gas - you can imagine what my wife and teenage daughters think of that...

I can try removing and cleaning whole throttle body - will I need a gasket to put that back together I wonder?

Ill try removing and cleaning the IAC thingy - but this whole - fine rpm then dip thing has me confused.

86cj74.2L 11-04-2013 10:23 AM

The throttle body is o-ringed. No gasket needed same with the IAC

derbartman 11-04-2013 10:30 AM

What is safe to use to clean the IAC? throttle body cleaner, break cleaner, brush and water...

Jeeples 11-04-2013 10:40 AM

Quote:

Originally Posted by 970001zj (Post 17399250)
odd thought why dont you just warm it up ?

it will give better gas mileage and power along with less wear and tear

Idling for ten minutes gets you 0 MPG.

As long as the OP is using a quality motor oil in the correct grade, there really isn't any need for more than a 1 or 2 minute warmup time. Staying conservative with the throttle the first couple of miles driving will be all that's necessary to get the engine up to temp quickly.

Quote:

Originally Posted by derbartman (Post 17422585)
What is safe to use to clean the IAC? throttle body cleaner, break cleaner, brush and water...

Throttle body or brake parts cleaner with an old toothbrush is generally what I use. Make sure you DO NOT pull the pintle out of the IAC motor itself. Be generous with the cleaner, and don't forget to clean out the passages in the throttle body itself.


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