No Start when cold

[Bamaprez]

1991 Ranger 4.0 4X4 Auto. Motor out of 93 Exploder been in the truck for 9,000 miles. Truck ran great until the outside temp droped below 30 degrees. Now it will not start when cold. you can start it with starting fluid once in the AM and it will start all day and run fine until the next morning. Ive changed the fuel pressure regulator, I've removed the temp sensores and checked them with hot water and a meter, checked the fuel pump. I'm at a lost. I've been pulling wrenches in one way or the other for almost 30 years and this little white SOB has me stumped. Its been a great little truck but now I'm walking because I let a friend borrow my superduty last week and they totalled it. When it rains it comes down in buckets around my house. Oh yea to add insult to injury the old lady is in the hooss cowww for a DUI and her truck is in jail for 30 days. I'm just waiting for the earth quake now.

Any Ideas

 

[pacodiablo]

Maybe there is water in the gas?

 

[snake]

When it starts with starting fluid, does it idle up as normal until it warms up? If not, there might be a cold start sensor that idles it up (don't know for sure) and that would use info from the temp sensors. Could be the PCM also.

 

[Bamaprez]

When it starts it Idels up fine idel comes back down after eng gets warm. no stumble runs fine.

 

[snake]

How'd you check the fuel pump? If you listen carefully when you turn the key on it will "zzzzzzzzzzzzzzzzzzt" for a few seconds and stop. Does it do this?

I am out of ideas as well, odd problem. Let us know of your progress.

 

[Bamaprez]

Fuel pump run when you turn key on. I checked press at schrader valve the first time I found it a little low so I changed the Fuel Press Reg. Now good pressure. but no effect on main problem. Fuel, Spark, Compresion = Bang in the universe just not in my driveway.. My next step is the fuel pump for geee wiz. I had a Grand AM in my shop about 8 years ago with the same thing it ended up being the little rubber hose that conects the fuel pump in the take had a small whole in it. I just didn't want to drop the tank in the snow. I just moved and no longer have a garage. Thanks for the brain cells though.

John

 

[martin]

Mine does the same thing, more or less. If I crank it for long enough it will eventually start. Problem is as the temperature gets colder the ability of the battery to crank for long enough deminishes. I will solve my problem by driving my 84 b2 during the cold weather, that sucker starts no matter how cold it gets.
I will be watching this thread with great interest though.

 

[Bamaprez]

I checked the ignition tonight intermittant spark at the plugs. Will try new motorcraft plugs tomorrow.

 

[Bamaprez]

Well I changed the plugs with Motorcraft and after a little work got it started. It still acted like it was flooded but it cleared up and runs and cranks fine tonight. We will see in the AM if it works.

John

 

[Bamaprez]

Well we are back to a no start when cold. even changed the battery to the one out of my superduty for shits and giggles.

 

[funkingonutz]

put drygas in the tank before you go to bed at night????
hey its an idea......try it

 

[naford]

I know this sounds stupid and maybe you looked at this. But turn the ignition on count to 20 ( or if can here the pump until it stops ) then turn the key to start. I'm thinking the only thing that could be happening is the gas is leaking back into the tank. So you don't have enough fuel pressure to start and the battery can't supply enough juice to turn the motor over and run the pump. It's a guess and probably a giant leap.

 

[Bamaprez]

NO such thing as to big of a leap. After pulling wrenches for over 30 years I love the simple fixes. Naford that was my thoughts as well to begin with. I thought the check valve for leaking back down was in the press reg thats why it was one of the first things I changed. I put a bottle of Heat in last night to no effect Thanks NUT. I thought bat might be low so I put a 1000 amp in out of the superduty and have tried most morning with a 100 amp boast box on it also. Is there a Cold start injector on this motor. 91 4.0. I can't find one but that is what it acts like. The fuel pump stops running after about 1.5 secs when you switch on the key. When it started getting cold I would have to cycle the key twice to get it to start. Now you can cycle it 10 times with no effect. Where is the check valve located for the fuel system?

John

 

[Bamaprez]

Well a little bit more trouble shooting and If I ground the fuel pump test lead to make the fuel pump run constantly It cranked this AM at 15 degrees after about three seconds of engine turning. Now to decide if it is fuel pump control or fuel pump leakdown that is causing it. I will keep you informed.
John

 

[naford]

I think the check valve is in the pump itself. If this thing has a cold start injector it should be in the intake manifold and shouldn't be that hard to find. (right) You wrote that the injectors were working? It's almost like the computer thinks it's missing something or that something is out of wack. I know that when I had a Fiat if it thought there was no oil pressure it would shutoff the fuel pump. I wonder if it thinks there is no oil pressure or maybe it thinks it's summer outside when in reality it is cold. Like there is an outside air temperature sensor in the air intake before the throttle body or maybe in the throttle body?