Hard start when cold and low engine temp. Now with code P0174 & P0171

[2000co]

I have two problems that may be connected.
First problem is new, when it's very cold outside the truck having hard time to keep idle after it starts. It will go to 1500 RPM and then idle to 500 and then start “couching” and die. Sometimes i need to push the gas pedal to help it to start. When it's warm no problem starting. I replace the fuel filter 2 weeks ago.

Second problem, i notice couple months ago that the engine Temp gauge needle is not in the middle like it used to be. It sitting lower then the middle but above the recommend temperature marking. Now that it's cold outside it will take it longer to warm up. I notice when you first drive the truck it will go almost all the way to the middle and then drop lower and stay their.

Now i'm getting code P0174 & P0171. It was -7 last night

 

[the_aszman]

1st problem sounds like the iac (idle air control) valve ,search for threads on cleaning or replacing it.

2nd sounds like a thermostat,could be sticking or wrong temp range for the winter.

i'm not to familiar with the sohc though so maybe someone else will chime in that knows the sohc better.

 

[2000co]

I have 4.0 SOHC

 

[VinnieBoombots]

Reading this post I could have written it... same two problems. Just made the rounds today to PEP Boys and Ford for IACV replacement. Part alone from Ford $120 plus labor. PEP Boys, $56 for the part, $80 labor. Wound up going to AutoZone, picked up the part for $46 with the gasket. Didn't want to do it myself because of arthritis and the temp was around 22 today in Central NJ. However snow tomorrow again, so did it. Ran the truck for a few hours and the idle problem seems to be fixed. I say seems, because it is hard to tell after the engine is warmed up. Tomorrow morning will tell the tale.

As far as the thermostat, that will have to be a wait and see also. Both Ford and PEP Boys are very expensive for that procedure and my hands won't work. I am getting heat in the truck, but not the usual. Temp gauge only reads half of what it used to. I believe the last time, 2 years ago, I replaced the thermostat it was a failsafe type.

 

[the_aszman]

you could place a piece of cardboard in front of the radiator to get some heat till you can get to the thermostat.only cover about 3/4 of the radiator,not the whole thing,you want some air getting through it.

 

[bikeboy]

My '99 SOHC just turned over 57K orig. miles and I am in Central NJ as well. I cleaned my IAC valve a couple years ago with Gumout and re-installed. It is a common problem with them sticking, every 40K or so...

As for cold running...these trucks have very good cooling (overbuilt) systems, IMHO. I have a 180deg. STANT T/Stat in mine and now in wintertime, the truck barely gets over 1/4 on the temp gauge. Funny, my wife won't ride with me in the winter anymore, cause she says it takes TOO long to get warm inside!!! Lol!

 

[2000co]

Will this fix my codes or i need to replace the intake gaskets?

 

[bikeboy]

How many miles are on your EX? The IAC valve is the easiest thing to do FIRST! Remove it and clean it with GUMOUT carb cleaner. Thoroughly...

If that does not create a better start-up and smooth idle, then you may need the intake gskts replaced. They are a royal PIA to replace! I had the dealer do mine, and also replace the timing chain TSB while it was apart.

 

[2000co]

105k

 

[VinnieBoombots]

Update to post

Reading this post I could have written it... same two problems. Just made the rounds today to PEP Boys and Ford for IACV replacement. Part alone from Ford $120 plus labor. PEP Boys, $56 for the part, $80 labor. Wound up going to AutoZone, picked up the part for $46 with the gasket. Didn't want to do it myself because of arthritis and the temp was around 22 today in Central NJ. However snow tomorrow again, so did it. Ran the truck for a few hours and the idle problem seems to be fixed. I say seems, because it is hard to tell after the engine is warmed up. Tomorrow morning will tell the tale.

As far as the thermostat, that will have to be a wait and see also. Both Ford and PEP Boys are very expensive for that procedure and my hands won't work. I am getting heat in the truck, but not the usual. Temp gauge only reads half of what it used to. I believe the last time, 2 years ago, I replaced the thermostat it was a failsafe type.

Replacing the IAC for $46 did the trick with the idle problem. The thermostat problem is still there with a slight twist. I was idling for a while, while cleaning the snow off the car and the gauge came up to the usual low position. Then I noticed it momentarily rise and return. I seem to get enough heat to warm the windows and interior, just not like it used to be. Maybe my bones are just getting older. Hopefully it will warm up a little and I'll replace the thermostat.

If it wasn't for all the great posts here, I would not have the confidence to do some of my own repairs. Thanks

 

[2000co]

I clean the TB, MAF, IAC and put new fuel filter. So far looks good. Thanks guys!!

 

[2000co]

It's -12F today and the truck still having issue starting when it's that cold, I don’t blame it. Before i change the intake gaskets I’m going to test the MAF, PCM and fuel pressure.

When i cleaned the IAC i notice it's in the open position is that correct? How can I test the IAC?

 

[chapsdeva]

If you were getting those two codes and the symptoms you described I would almost guarentee it's your intake gaskets. They are shrinking with the extreme cold causing a too lean condition...thus the codes. It was smart to try cleaning the IAC (even though that doesn't always fix a bad IAC), MAF and adding a new fuel filter...all good for the truck even if they were not the problem. There are write ups on this site on replacing the intake gaskets...not an easy job, but certainly doable if you are handy with a wrench. Good luck!

 

[DoraThe_Explorer]

Just throwing this out there but I pulled the same two codes on my truck before I replaced the upper intake manifold gaskets and timing chain cover gasket. Over all improved performance of my truck once the work was done.

I also use 5w 30 oil in the cold weather. That helps a bit with those cold mornings too.

I also stumbled across a walk through for the timing chain cover gasket for the sohc.

http://www.explorerforum.com/forums/showpost.php?p=487634&postcount=33

Good luck with what ever you end up doing, and have fun in the snow tomorrow!

 

[joe doe]

i know what is wrong with your truck ,but to avoid repeating myself i will refer you to this thread here where i explain whats happening and how to fix it .
anyone getting those 2 lean codes(bank 1 and 2 lean)should read this here link.

read all of it
http://www.explorerforum.com/forums/showthread.php?t=304739