Made a thread the last time it was in the negatives about this. Truck plugged in right after I get done driving it, or over night, turn key, real real low RPM stumbling, rev up, than its fine. Sometimes I have to tap the gas. passed two days we have been in -16F, but with the truck plugged in, I would expect a better start up.

Is this because the IAC valve is frosting up? Has anybody fab'd up a blanket for it? Like a battery blanket?

I get real quick revs when starting and it fires almost immediately, I just hate the stumbling. I would expect more out of a plugged in gasser. The 6.2 diesel in my neighbors H1 fired right up this morning after two days of not being ran, although plugged in. . .

 

I would start with cleaning the IAC. While you are at it wash out the tubing leading to the IAC and the tubing coming off of the driver side dam cover.

 

No not frosting just sticking.
It needs cleaning.
Have to take care of these things or they just haunt you during winter months.
The IAC is supposed to open all the way for starting then close a bit to give the motor it's high idle, then slowly close more as the motor heats up and the OX sensors take over fuel control.
There is also some PCM timing involved in very cold temps to keep the IAC from closeing to far to soon and stall on drive-away. This is done by senseing the coolant temp.
In some instances the cold start idle could hang somewhat higher for as much as several minutes while the motor gets up to temperature.

 

Definately. Just brake cleaner and some kind of brush to clean it??

 

I'm running a insulator on mine (stock from Ford). - They will freeze after shut down when conditions are right. - if you let her sit and idle allot or make allot of short trips when it's cold. Pull the line from the manifold and you'll see - not kidding. Look under your oil filler cap. If you have that white milky looking sh^t, it's contaminating the IAC.

Sea Foams "Deep Creep" is the best IMO - Cleans/lubes/sensor safe. Ford states - The IAC cannot be cleaned for some reason ? I disagree.

Yea, you CAN shoot it w/brake clean if you want, but you need to hit w/compressed air immediately. Then follow up w/WD4O/hit it with compressed air again.

Also , make sure to work the mechanicals inside the sensor w/small screwdriver. Carefully.

And like JMC said, -blow out the line.

Hey, did you tune your PCM going from a 4six to a 5four? Or are you still running your 4six tune?

IAC info - http://www.fordf150.net/howto/throttlebodyclean2.php

 

For these past few weeks my block heater wasn't working (wasn't plugged back in lol) well anyways these past few days if and when I decide on going some where I typically plug my truck in for about 1/2 an hour to an hour usually and then go about my day. well when I plug my truck in it likes to do as you say stumble upon start up. Mine will typically rev up to about 1300-1400 rpm like it has actually started then fart, buck, kick, snort, back fire and then die. I have found it to be when I only plug it in. Otherwise runs and drives perfect.

 

-14 F this morning. No block heater and it still started right up. Maybe a little slower than yesterday but no real issue. 127K miles and still going strong.

 

Yea , what's with the block heaters ? I never needed one either ??

 

Where would one find the plug for the block heater on a 2001. I havn't had to use it yet but this cold is taking its toll..... I must be missing something... I will be very suprised if she doesn't have one.

 

Yes my PCM was tuned. Diablosport chip and a basic 5.4 tune

 

It is not standard. You have to buy one.

 

Trucks built for Canada should have them standard. Get under the truck and on the driver side find where the dipstick tube goes into the oil pan. To the rear of that on the block you should see it. Follow the wire to see where the plug is. You may just have the heater and no extension. If you don't have one a trip to Crappy Tire will fix that.

 

My truck was a Michigan truck and had one from factory.

 

Mine didn't - Dads 99 7.3 use to, but he never used it as far as I know.