Cold Weather - No Start (again)

[KUlmer]

Hey Gang,
Well, it's cold in NE Ohio again and my '97 Explorer Sport (4.0 SOHC) 4x4 is giving me starting fits again. I hope someone can help please.
Two winters ago this started where my Ex wouldn't start on really cold mornings only(below 10-15 degrees). Dealer replaced the IAC and all was good.
The next winter (last year) it did it again a couple of times. I pulled the IAC once and brought it in to the house to warm it up. A neat trick I learned here, thank you! That seemed to work. Took the vehicle in and the dealer replaced the IAC again. They also suggested that the battery might be weak so I replaced it. A week or so later the car wouldn't start again. By the time I got home from work that evening, the Explorer was fine (but my Mustang was really pissed about having to go out that morning). Anyway, that was the last of the cold weather for the year so all was good.

Fast forward to this morning. As I was afraid when I looked at the 18 degree reading on the thermometer, the Ex wouldn't start. It cranked really hard and sputtered a couple of times, but no start. No noticable exhaust if it fired on those sputters. No time to monkey with the IAC this morning. Had to go wake the Mustang up to get me to work (not a happy car). By the time I got home this evening, it started ok. It cranked for a few second more than usual, but sarted up kinda rough and ran fine afterward. The only thing was that the exhaust smelled really, really bad for awhile. I shut it down and then started it and it started right up.

The dealer's main culprits last winter were the battery and the IAC (both got replaced). The only code they found was a flood condition. Probably because I was trying anything in my desparation and pumped the crap out of the gas pedal. (Hey, it used to work on my old '73 Gran Prix.) Actually, I think I read here that if it is an IAC problem, slightly depressing the gas might help. I guess I over did it. Anyway, they couldn't find anything else.

Could it be another IAC? Everything I've read in previous posts makes this sound like an IAC problem. The symptoms lead to that, but this current IAC has less than 10k miles on it. Anybody have any other thoughts? The winter has just started, I really don't want to buy snow tires for the Mustang!

Thanks as always for your thaoughts and help!
Sorry so long.

Ken
Twinsburg, Ohio

 

[Blee1099]

Tomorrow or the next time in cold conditions, turn the key to on for 3-5 seconds and then back to off and then start the truck. If that works, then its a fuel related issue.

 

[KUlmer]

Thanks for your speedy response Ben!

Tomorrow or the next time in cold conditions, turn the key to on for 3-5 seconds and then back to off and then start the truck. If that works, then its a fuel related issue.

How critical is the 3-5 seconds part? The first time I tried to start it, I cranked it for about 10-15 seconds. The occasional sputter gave me hope so I cranked some more. Then I shut it down and waited for a few as I started the other car to warm it up. When I tried again after a few minutes, not even a sputter. Just hard craking.

Assuming 3-5 or 10-15 second would have the same results(?) do you think I can rule out fuel? If so, any other thoughts?
Thanks,
Ken

 

[ExplorerDMB]

pumping the gas on a Fuel Injected vehicle doesn't do a thing. The computer doesn't read from the sensors until it is in closed loop. When you start the vehicle its on its own way of things.

http://www.explorerforum.com/forums/showthread.php?p=1330443

-Drew

 

[ExplorerDMB]

How critical is the 3-5 seconds part?

He's not talking about "crank"time - hes saying to turn the key to the on position (like to run all your accessories) and then after 5 seconds turn it off and then try to start it after that. It's basically to prime the system.

-Drew

 

[Blee1099]

Yup.. On some of the older 95-2001 Explorers in cold climate conditions it takes a few extra seconds for the fuel pump to prime the engine.

 

[KUlmer]

Drew,
I kinda though pumping (without cranking) would do nothing, but what about holding the pedal down while cranking? Will that not advance fuel to the injectors (because of the cranking action)? Not to argue, but understand, how would I cause a flood condition (briefly)?
Thanks for the cool flow chart. Unfortunately, my problem seems to be the shortest path of flow without too many specific items to check out to narrow the problem to one item. I guess ignition or fuel system can be a pretty broad problem.

Thanks also Drew & Ben for clarifying Ben's reply with the "turn to on" without cranking tip. Now I get it. I guess I was reading to much into it. Just trying to jump right to the start.
Thanks again.
Ken

 

[dogfriend]

Drew,
I kinda though pumping (without cranking) would do nothing, but what about holding the pedal down while cranking? Will that not advance fuel to the injectors (because of the cranking action)? Not to argue, but understand, how would I cause a flood condition (briefly)?

Thanks again.
Ken

The Ford fuel injection system is designed for a "no-touch" start. In other words, you should not need to touch the accel pedal for a cold start - the PCM will take readings from all sensors during the first few cranks and adjust the fuel/air ratio for the ambient conditions. The air is adjusted by the IAC duty cycle (how much air is let in) and the fuel is adjusted by the injector time on.

Cracking the throttle slightly may help in the case where the IAC is sticking because you will let some extra air in - what the IAC is supposed to do if working correctly.

BTW - my IAC sticking problems occurred during warm weather only after the truck was warmed up.

I'm wondering if you might have a bad Intake Air Temp sensor or Coolent Temp sensor - but you should get a Check Engine light if that were true.

IIRC - When you hold the throttle to the floor (WOT) during starting, you are signalling the PCM that you have a flooded engine and it will cut down on the injector on time to help clear the flooding condition. It is much easier to cause flooding during cold conditions than when warm because the fuel will condense on cold engine parts. You need gas vapor for combustion, not liquid.

 

[KUlmer]

Thanks Dogfriend for your great explanation of the fuel system. Now I understand a bit better.
We'll see what happens here. I will be starting it soon as I have to go to work this am. The temp is about 25 degrees right now. I have a good feeling today. I'll keep you all posted.
Thanks again.
Ken

 

[KUlmer]

Good News!
It started this morning!
I kinda thought it might just because we are having a "heat wave". It was a whopping 25 degrees F on the console thermometer when I went out. Just to be safe, I tried Ben's tip turning on then off then start. It fired up pretty well on the first try, idled a little rough then stalled twice after a minute or so. On the third start, as the idle stuttered, I tweeked the gas pedal a bit to keep the idle and then it ran fine, It drove to work fine also.
I'm not ruling anything out since it wasn't nearly as cold this morning as yesterday.
We're supposed to get "spring like" weather for the next few days, so I might be in the clear for a bit. We'll see.
Thanks to all for your help (once again). Please feel free to continue to reply if you have any further thoughts or ideas.
Thanks,
Ken

 

[KUlmer]

Hey Gang,
Here's a follow up question related to my no-start problem.
Can an incorrect plug gap effect my starting ability in cold weather?
I had about 60 degrees today and thought it would be a good day to change plugs (new Motorcraft Platinums). Couldn't hurt, right? The old plugs, Bosch Platinums, had about 35k on them so I thought I would give it a try. The Autozone guy said the gap was .05. As I pulled the old plugs I checked some of them. It seems I had them gapped a bit smaller than .05
After I thought about it, I remembered that I installed those plugs in August of '03 and my cold weather starting problems started that winter, and then again the following winter (and then this winter again). Could this have been causing my problems?
Also, someone with a similar problem in another message suggested that too heavy of an oil may cause starting problems when it is really cold. Could this be true?
Thanks agin,
Ken

 

[96limitedX]

just somthing i heard and used about holding the gas down on a EFI truck. my '91 f-250 EFI 5.0 had been sitting out in -10 weather. i went to try and start it and it just cranked. after a few trys it smelled like gas. really strong..like it wa flooded. we let it sit with the battery charger on it(because i ended up running down the battery trying to start it) then i went out and it did the same thing. so i went and asked what could the problem be on fordtruckworld.com and the guys there said to hold the gas down and that would tell the computer not to give gas to the truck. so it would not keep flooding it as it had been doing. well i put the pedal to the floor and cranked it and it fired right up. worke great..but i dont know what it would do to a OBD2 system. but on the OBD1 it works.

 

[dogfriend]

Can an incorrect plug gap effect my starting ability in cold weather?

I would think that it might be a problem if the gap were too large rather than too small, as you describe. My reasoning is that it is harder to fire the spark across a larger gap.

Oil viscosity can definitely affect starting in cold weather. That's the reason they invented multi grade oils in the first place. 5W30 should be good unless you live in Canada, eh? One of the biggest advantages of synthetic oil is that they flow well at low temps.

 

[KUlmer]

Thanks for the response Dogfriend.
My thinking was that perhaps too small a gap might produce too small a spark to facilitate combustion when the engine is really cold. But that's just my screwy logic. If I knew what I was talking about, I wouldn't be bothering you folks.
As for the oil "oh yeah" I forgot about that fact. I think I used 5W30 at the last change. Just about due for another change.
Thanks again,
Ken