Weird Idle Issue

[CobraHuck]

The last couple days when I've been driving my car ('97 Cobra) around, when I come to a stop it's idling really low compared to what it did when I bought it a couple months ago, it died on me yesterday, and I'm just generally confused. It never used to do any of this except for a little erratic idling with the A/C on.

What it used to do:
When I'd push in the clutch and put it in neutral rolling to a stop, it'd hang around 1100-1200 until I came to a stop, then drop to normal idle. My buddy's '97 does the same thing so I figured that's about normal. When I'd turn on the A/C, it'd idle up and down a little as the compressor engaged/disengaged and when driving I could feel it through the car when it'd kick on. Was thinking that's not really normal tho

What it does now:
When I push in the clutch, it drops to ~8-900 rpms immediately, and idles around 5-600 once I'm stopped. When I turn on the A/C, it'll idle up and down (seen it as low as 3-400 and it'll barely catch itself) and it died on me yesterday while I was stopped with the A/C on.

It just started doing this after I put in new Autolite Platinum plugs and a new PCV valve. The next day, my buddy was telling me that everyone on here swears that you need to run the Copper plugs, could the Platinums be causing the problem? I took off my IAC and it's clean/fairly new, don't know about my TPS, I tried testing it but can't get a reading. Gonna try cleaning the maf next

Any ideas??

 

[Murder Snake]

there has been some issues sometimes others have experienced with aftermarket pcv valves.

 

[CobraHuck]

^Thought about that after talking with my dad. I threw in the old Motorcraft one and it's still acting the same. I'll probably pick up another Motorcraft to throw in, not sure if this one is good or bad...

 

[Murder Snake]

^Thought about that after talking with my dad. I threw in the old Motorcraft one and it's still acting the same. I'll probably pick up another Motorcraft to throw in, not sure if this one is good or bad...

when you do, get the grommet too, just to make sure. then you can eliminate that if it still does it.

 

[SNAKEYE]

Did you clean the IAC (flush with carb cleaner, brush with toothbrush to remove stubborn dirt, DO NOT try to move the pintel as it is motor-driven), or just pronounced it good-to-go based on its appearance?

 

[CobraHuck]

Just pronounced it G2G cuz when I took it off it literally looked brand new. Gasket even looked new and still pliable, absolutely no build up inside, nothing. The port into the intake was somewhat dirty but nothing out of the ordinary

 

[CobraHuck]

Figured out my issue. When I bought the car, it had this weird home grown oil separator on the drivers pcv. Over the 2.5-3 months I've had the car there's never been any oil occumulation in it so I figured it was not working properly.

Well, I put in a new PCV and just a hose from it to the intake and it started the weird idle. I had a hunch this morning and threw the oil separator and old PCV back on and it's back to normal. No more low idle or dying. I have no idea why, but that fixed it. The thing looks like hell and never catches any oil but if it keeps her running good I'm keeping it.

 

[Murder Snake]

same one I made, but mine is mounted and with nylon fittings. works great. yours looks like it is burned thru on the bottom on what would be the valve to empty. mine wouldnt seal so I glued mine shut and I unscrew the canister to empty it.
important part...you found it. good thing you started messing with the PCV...allowed you to fix it!!!!!! Good job!!!!!!!!!

 

[CobraHuck]

How often does yours need to be emptied? Mine's not burned through, it's just got residue and crap inside (I need to wash it out), but it's never really collected any oil. That's why I assumed it wasn't working.

I'm glad it fixed it, I'm just a little perplexed as to why it runs better this way than with a more factory style setup

 

[Murder Snake]

empty mine about 2x every oil change (3k). would be interesting to know what the difference is between the set up you have with more connections and what you had changed.

 

[CobraHuck]

Hmmm...maybe I'll try disassembling this one sometime this week and cleaning it out/seeing if it's letting anything through. Might try to make/buy a new separator setup to see if it'll work and keep the car running good.

Or maybe I'm just not venting much oil in the first place? :shrug:

 

[4valved]

I have that same catcher it seems to work ok?

 

[DamnNiceL]

I am guessing MAF or Throttle body

 

[Murder Snake]

Figured out my issue. When I bought the car, it had this weird home grown oil separator on the drivers pcv. Over the 2.5-3 months I've had the car there's never been any oil occumulation in it so I figured it was not working properly.

Well, I put in a new PCV and just a hose from it to the intake and it started the weird idle. I had a hunch this morning and threw the oil separator and old PCV back on and it's back to normal. No more low idle or dying. I have no idea why, but that fixed it. The thing looks like hell and never catches any oil but if it keeps her running good I'm keeping it.

my setup: