So I cranked "the money pit" yesterday to go out for a little shopping with the wife. It had been parked all night so the engine was "cold."
As soon as it cranked, the idle was very rough and seemed like the car wanted to stall out. So I popped the hood to see if I could tell anything at all was obviously wrong (this rarely ever works, but I think as a man it makes me feel better to pop the hood and look in there.) Another thing we noted was an extremely strong exhaust smell (like the engine was running rich.)
Then the idle evened out to normal, and the car performed all day like nothing had ever happened. I cranked it this morning and it cranked fine with nothing out of the ordinary.
Soooo...does anyone have any ideas?
Clogged EGR valve/ports?
Something amiss in the EVAP system?
The posts relating to EGR vlave/ports usually mention a constant rough idle though. This only happened one time when theengine was cold.
The car does have a CEL, and I know it is an o2 sensor code (can't remember which one.) I'll go back to AutoZone again & have them scan the codes and give me the exact number this time.
Anybody got any ideas in the mean time?
I almost forgot to mention. The car has been making a really wierd whining noise occasionally on startup. If only lasts about 3 or 4 seconds. I have never been able to re-create this whine with the hood popped to locate it either. I don't know if that tells anybody anything.

 

I'm thinking that the ECU is reading too lean causing too much fuel to be injected. This could give the effect of choking the car to a stall. Is your O2 sensor actually bad or is the code for something related?

 

How old are the plugs, wires, & dist.cap?

Misfiring on startup can be plugs, or else distributor cap & wires. Try looking for arcing in the dark, especially when it's cold & damp.

Plug wires or cap can have microscopic cracks or pits that provide a path for the electricity to short to ground. After a few seconds they get warm & dry out; then they work OK. This gave my brother fits with his car (years ago...)

If you have to crank the starter a little longer, that drains your batterya littlemore. Then your alternator has to work harder for a little bit. That would be a whining sound, as opposed to a squeal sound of a slipping belt. OTOH, it might be a very early sign of a diode going out inside the alternator?

 

I think Jim has got it nailed.

You mentioned that it was "cold" out that morning. By any chance was it especially humid on the previous day, and was there byany chance some condensation on the car the next morning? (In Florida in the morning, even ifa car hasbeenunder the roof of a car-port all night,it will very often look likeit's been rained on - big drops of water all over it.)

If there was, then likely there was some possiblecondensation inside the distributor cap, too (I doubt ifthe dist isair-tight), and on the outside of the plug and coilwires - a perfect situation for very minorarcing and shorting in the ignition system.

Then, as Jim said, the heat of the engine dried everything off and then the engine ran fine.

If it happens again, take particular note of what the relative humidity was for the previous 12 hours, or so. A really hothumid day followed by a very cool night is a recipe for a rough intitial start-up.

 

Dirty FITV? maybe? Has it happened again since? Is your wife sabotaging the car in order to have exuses to be upset? *L* Doubtfull it's an EGR issue, could be a problem related to the already bad O2 sensor causing it to burn to rich...

As for poping the hood and looking I agree.... it's always a good idea to do it just to show that you are trying! There is only once in my life that opening the hood for a look showed me the problem instantly...

 

Well ....... if there are smoke and flames comming out of the sides, I think that I'd pass on popping the hood, but otherwise, why not

 

The plugs were changed about 6000 miles ago. Wires looked brand new at the time with no arcing. Dist cap looks brand new as well, not even a speck of dust on the inside. It has Denso plugs.
By "cold" I meant about 80 or 85degrees outsideat the time I cranked it. But...Tony may have a point. It actually has beenin the 60's at night recently.It is always humid in Mississippi (normally between 80 & 90 % humidity.) The car stays in the garage with the garage door down at night.
I need to go by AutoZone to re read the codes.I am not positive exactly which one it is throwing.
The whining sound is actually kind of like a whirr sound. This sound occurs only occasionally, and does not make itself known until asecond or two after the engine is already cranked and the starter is no longer turning. But of course, by the time I get the hood open,the sound has stopped so is impossible to locate. I need to leave the hood open every single time I crank the car from now on to find it. It should be obvious where it is coming from.
The starter actually had to turn over a few more times than usual to crank the car, the time of the rough idle incident.
It has not done the same thing since.
It almost seemed to me like too much fuel was dumped in, and was not able to fire correctly, then the stongexhaust smell.
I will watch forto happenagain, and go to AutoZone and pull that code.
Thanks guys! I'll let y'all know if I figure anything out or if anything different happens!

 

With that kind of humidity you may have some dew laying on the cap & wires when this happened. Try looking for arcing in the dark, & spray water with a windex bottle. Or wake up before dawn & try this when there's dew laying all over it.

Open hood first, have someone else start it. Possibly the starter pinion gear coasting to a stop after the engine starts? That would only make senseif it's IMMEDIATELY after you let go of the key. (You already know it's pretty hard to guess noises over the web...)

 

Wait a minute... It's a '95...?
What about the ABS modulator pumping itself up to operating pressure?

 

I was thinking the same thing!