Hard starting in cold
 

At least it started acting up when it started getting cold..

Here's the facts about the truck first.
120,000 miles, burns about a quart every 5000 miles (also the time frame in which I change oil) About 40,000 miles on plugs and wires. Just changed fuel filter. battery about a year old

So it will crank fine, spinds like a top. Sometimes I have let it sit for 30 seconds or so with the key off and it fires right up. Before I changed the fuel filter I let the key on for a few seconds thinking it was plugged and needed time to build the pressure. Always seemed to fire after doing that.
Sometimes it would fire right away but stumble like lack of fuel. If I shut it off and then tried again with leaving the key on before cranking it would run fine. This led me to think the filter was plugged and why I changed it.
Filter had about 50k on it and what drained out was absolutly filthy.

This morning it wouldn't fire again. Tried my usual tricks but no go. I was already late so I just took the wife's car. So I havn't been able to pull any plugs. Happens wheather it sits in the garage or outside. THis morning was the first time it hasn't started since I changed the filter a week ago. Been starting just fine since then...

Any ideas?

I'd run some injector cleaner and drive it. Maybe high octane

With it being as cold as it is i would say put your battery on a charger or use a meter to see if it has enough amps to start the truck.

Swap out the fuel pump relay.
And throw in a can or two of drygas.

I have put in a can of seafoam after the fuel filter change and also been using clear gas instead of the ethonal blend.

I'll check out that relay. Do you know where it's located?

I should mention that this dosn't happen all the time. It was maybe 75% before the filter change and then only this one time since

Pull a plug first, if it looks ok and normal, run some fuel injector cleaner thru it with some High octane gas. it doesn't sound like a misfire or anything like that, just sounds like whatever went thru your dirty filter is gumming up your lines.
Your fuel pump relay will be in a box near the battery, Owners manual should tell you what Relay it is, some have it on the underside of the cover.

So what's up with the high octane recomendations? High octane is slower burning and will tend to carbon up the combustion chamber. I would think lower octane would be better as it would fire easier....
In Iowa 87 and 91 are clear and 89 has ethonal. So if the goal is to get away from ethonal anything but 89 will do the trick.

Seafoam doesn't like to burn at all. I hope you didn't use a full can in your fuel tank. Honestly, the stuff's over-rated. I use it sparingly, in the vacuum lines, but that's it. NONE goes directly in my oil (crankcase) thank you very much..



GB :)

I'm going to have to disagree on the use of Seafoam, but that's for a differnet thread. :)

I swapped the relays for the pump and ABS. Pump is still acting up and I still have ABS so that leaves the pump. Sometimes I can hear it whirring, sometimes not. Takes about 5-10 cycles turning the key off and on to get it to go.
I have a new pump on order and will swap it out when it comes in. Hopefully it survives long enough as it's a week out and I just filled the tank clear full. :sigh:

Check the connections to the enertia (sp) switch in the passenger side footwell.
They may have gotten wet and corroded .

I have been having this issue also. 2004 4.0. i have replaced the fuel pump, new fuel filter, swaped the fuel pump relay with the ac relay, new tps and new iac. truck turns over fine, battery has 12.9 amps. if it is below 20*f outside truck starts hard, below 15*f it simply will not start. i have not tried starting fluid yet because i don't have any. any advice appriciated.

Reason they don't have any Starting Fluid is because weather is too cold for gasoline or diesel engines to start easily, they are sold out, lol

Nothing wrong with your engine, its just physics of cold temps

Gasoline can NOT be ignited by a spark, movies guys take liberties with that FACT
Only gasoline VAPOR can be ignited with a spark

You may have noticed that gasoline smell is quite strong in summer, and almost non-existant in winter, thats the Vapor you smell, or don't smell
The colder the gasoline the less the vapor
Engines have compression which heats up the gasoline to a vaporize it, need at least 30% vapor for a cylinder to "fire" enough to start spinning the engine, under 30% and you get "pops", no explosive force
Cranking a cold engine does start to heat it up from compression and friction, but it also DROWNS the spark plugs in unvaporized liquid gasoline

Quick Start/Starting Fluid is Ether, ether is a vapor at lower temps, you can smell it, lol, and it can be ignited with a spark
Its probably you best bet for quick startup when it gets really cold
Pull off Power Booster Vacuum hose, spark some into the intake/hose, put hose back on
Ether will be sucked in when engine is cranked
Engine will fire up but may die just after, but that startup should have gotten some cylinders hot enough to vaporize the cold gasoline as it come in so should restart
If not, repeat


You can try this in the mean time
Turn on the key
Press gas pedal down to the floor and HOLD IT DOWN all the way
Turn key to START and crank engine over for 10-15 seconds, it should NOT start or even fire
Release gas pedal
Try to start engine normally
repeat if it doesn't start right up

All fuel injection computers have a "Clear Flooded Engine" mode
It allows the driver to TURN OFF fuel injectors while cranking the engine to clear out the gasoline that flooded the cylinders
Key on, computer on
Gas pedal to the floor(WOT) at 0 RPMs tells computer to shut off fuel injectors, enter "Clear Flooded Engine" mode
In this situation it allows you to use compression and friction to heat up the cylinders WITHOUT drenching spark plugs with cold liquid gasoline
May or may not work, but can work

thanks for the advice. i have tried the wot while cranking and then taking my foot off the gas, it didn't help. also the local part store does have ether, it is me that is out not the store.
for giggles this am, it was 6f i took my trolling motor battery out and connected it to my truck battery. i turned the key and still no start. i cycled the key 4 or 5 times and suddenly heard the fuel pump turn on, truck fired right up, so i think i have 2 issues. first my 7 month old napa battery is weak and second my 3 week old fuel pump is bad. i think i will put in a new relay when i have the pump redone. thank you for your reply.

Yes, fuel pump would be the issue, should hear it run for 2 seconds with key on, and each time key is turned from off to on

yup, it takes 4 or 5 cycles of the key for it to kick on. ugh.

Yes, 3rd party fuel pumps can be a pain, but good warranty, 1 or 2 years
Motorcraft fuel pumps just work, only 90day warranty, but 3 or 4 times the price of 3rd party
So its a trade-off

Extra cost is in Quality Control, tested before shipped, its less expensive for Ford to pay more for a tested pump than to replace an untested failed one at the dealer

it was a motorcraft pump, as is the iac and tps. i paid up it hopes of no problems. i am going to the dealer to see if they will change it for free, or give me a pump upfront and let me return the bad one..

Never read that before, Motorcraft fuel pump failure, but I guess it has to happen

yeah, it's my luck the stoopidest things happen to me :dunno: