97 I30 Common Cold Start Issues

[vonscorpio]

Along with the brisk fall air, and icy streets, another common sign that winter is coming is when my 1997 I30 has trouble starting in the cold mornings. Symptoms are the usual: kicks over, runs for half a second and dies, followed by the strong scent of un-burnt ethanol. Touch the gas right as it kicks over (momentary rev over 1,000 RPM) and she fires right up and runs without complaint.

I read on this forum and other internet searches this is usually related to an old gummed up fuel filter and/or a dirty MAF. I replaced the fuel filter with a Fram and while I was under the hood, removed the MAF and shot some of the MAF cleaner through it. Not only did this not solve the problem, but seems to have caused others. Ever since the swap & clean, my fuel economy has plummeted to 16 MPG from the average of 19-21 mpg. Perhaps correlating with the colder weather, but I track my mileage, and it worse than last year, when the KS and O2 sensors were all toast. I have also noted my idle is now lower, hovering right at 500 RPM in gear, which sometimes stumbles below the 500 mark. It hasn't stalled yet, but I suspect this might occur soon.

No check engine light, and no pending codes.

So for my question: did I mess up my MAF when I thought I was cleaning it? Is there an idle speed control I might have bumped while working with the fuel filter? Or is correlation no proof of causation, and I've got other issues on hand?

[NutriaforBreakfast]

I would try cleaning the throttle body
Maybe there is carbon in and around the inside of it

[vonscorpio]

Probably a good idea to do anyway, but is this something which would have gotten worse after working on the car?
Before I touched anything, it just took a little boost to start. Now, after "fixing it" I still have to boost it to start, it idles low and has dropped about 3 mpg.
I am honestly worried I damaged my MAF somehow.

[vonscorpio]

But wait! There's more!
When I got home from work today, I checked under the hood and discovered my harmonic balancer/main pulley is got a nice little wobble-- which might account for some of the erratic idling vibration.
I guess the fuel economy issue will remain a mystery for another day...

Any reason to use OEM vs aftermarket pulleys?

[NutriaforBreakfast]

If pulley must come off then its a good time to replace the oil seal if needed

[vonscorpio]

I've had bad luck with fixing "stuff which ain't broke". In my experience it causes new issues...(like trying to fix a cold start issue and potentially ruining a mass air flow sensor, for example)
At 182k miles, is it common to need to be replaced? Or is it a "you'll know what you see it" kind of thing?

[NutriaforBreakfast]

Not sure if common problem
I think mine leaks a little
I hate for oil drips to get on the crank position sensor but won't change it unless it gets worse
until it starts using quarts of oil

[vonscorpio]

My cabin side valve cover gasket leaks so much oil I'd never notice. Valve cover gaskets are on the list to be fixed, they just keeps getting pushed back with each of these new problems.
Sadly I think I have to go another week with the failing harmonic balancer. The part I ordered took more than the 2 days Amazon promised.

[NutriaforBreakfast]

leaky valve covers wont hurt too much
if the spark plug tubes leak oil on the coil packs too much that could be a problem
Plan on changing them when you change the valve cover gaskets

[vonscorpio]

Vehicle runs a lot smoother now, but still idles lower than before. Haven't had time to clean the throttle body yet.
Thanks for the advice on the front oil seal, NutriaforBreakfast. Turns out it was a major culprit in the total oil loss. Good thing I had the gasket on hand, due to your comment.

[NutriaforBreakfast]

There should be a screw on the idle air control valve to adjust the idle
The factory says not to adjust the throttle body for the idle generally

[vonscorpio]

So, I can adjust the idle with the idle air control valve (seems logical)? And as previously suggested, I should also clean the throttle body to help fix my cold start issues.
Perhaps I should know this, but what is the proper idle RPM for the I30? Prior to my last "preventative maintenance" with the fuel filter and cleaning the MAF, I could have sworn it idled at 600~650 RPM (A/C compressor off, AT in gear). Now its right at 500 RPM and just feels a bit low.

[NutriaforBreakfast]

it shows the rpm in the floor shop manual if you want to check
around 900-1000 rpm for park
650-800 rpm for drive