Starting during cold weather

[sbsrlewis]

My 2000 Explorer (SOHC) sputters and dies after starting while cold. It takes close to 5 minutes before it will maintain a good idle. Currently the Check Engine light is on and the codes are for the O2 Sensors which I changed less than a year ago. I also changed the Idle Intake Solinoid around the same time.

Anyone have any ideas as to why it would idle when cold? MAF?

 

[sbsrlewis]

Come on. I can't be the only one that has this problem.

 

[MAKG]

This is a volunteer site, and treating it like your own entitlement is a good way to get ignored.

 

[sbsrlewis]

This is a volunteer site, and treating it like your own entitlement is a good way to get ignored.

Excuse me, didn't realize that I was using for my own entitement. I was just trying to use a little humor to get my post back to the top after a day and a half.

 

[Evan]

Excuse me, didn't realize that I was using for my own entitement. I was just trying to use a little humor to get my post back to the top after a day and a half.

Don't worry, I took that as a humorous statement.

I have a similar problem. I have had no luck making a positive diagnosis. When I start my Explorer, it starts normally and runs well for several seconds. Then the RPM dips, the engine starts missing, and I need to blip the throttle to keep it alive. Once I give it a little gas, it stays alive on it's own but misses and runs at a low RPM. Once the engine warms up, it runs fine. My engine is not throwing a code at that time. The problem occurs most/worst when it's cold.

I have checked or replaced: MAF, IAC, O2, plugs, injectors, and more

I rebuilt the engine about 2 years ago. The rebuild included hot tank and honed block, ground and polished crank, new rods, pistons, seals, main & rod bearings, gaskets. I had a shop do a quick visual inspection of the heads, and they said they were "useable."

I think that I may have a leaky valve stem seal. When the engine sits it causes oil to leak down and pool on top of the valve. When I start the engine, it runs normally for a second or two, but then the opening valve releases the pool of oil into the cylinder, fouling it. After the engine runs a bit, the oil is burned off and/or exhausted and the cylinder is unfouled. This explains why my engine with a brand new bottom end burns 1/2 quart of oil every 3000 miles. Is your engine using any oil?

 

[sbsrlewis]

I have a similar problem. I have had no luck making a positive diagnosis. When I start my Explorer, it starts normally and runs well for several seconds. Then the RPM dips, the engine starts missing, and I need to blip the throttle to keep it alive. Once I give it a little gas, it stays alive on it's own but misses and runs at a low RPM. Once the engine warms up, it runs fine. My engine is not throwing a code at that time. The problem occurs most/worst when it's cold.

Is your engine using any oil?

That's the way mine runs on a cold morning also. I talked to another guy at work and his is doing it too. I do have the codes for the O2 Sensors but nothing else. Like I said I replaced them less than a year ago but may go ahead and replace again. I believe they have a 1 year warranty.

Not using any oil.

Thanks for the help.

Steve

 

[Wicked_Sludge]

what exactly are the o2 codes? rich/lean mixture? or something else?

 

[sbsrlewis]

what exactly are the o2 codes? rich/lean mixture? or something else?

Oops. I was looking at the OBD-I Codes instead of the -II Codes. But anyway I am getting P0171 (System Adaptive fuel too lean - Bank 1) and P0174 (System Adaptive fuel too lean - Bank 2). What does this mean?

Steve

 

[smokey]

Lean codes could be from allot of things. Vacuum leaks is were 99% of my lean codes came from but it could be alot of other things causing them.

 

[Wicked_Sludge]

with the poor idling and lean codes its almost surely a vacuum leak.

you can check for vacuum leaks in a number of ways. spray question areas with starting fluid and listen for a raise in RPM (dont forget around the upper and lower intake manifold gaskets, 4.0's eat these gaskets for some reason). there are also smoke machines that will fill the intake with smoke which will leak out of...well, leaks.