Rough idle when cold - Running rich

[siteunseen]

Here's a good read if you haven't seen it yet.  Info on the AFM and ways to tell if it's been messed with, the "glue blobs" on the nuts.  Thanks @240260280

"you will also notice a blob of silicone or glue. If this is broken, you can immediately determine that the AFM was "messed with".

http://atlanticz.ca/zclub/techtips/afm/index.html

http://atlanticz.ca/zclub/techtips/EFI&fuel.htm

[Zed Head]

18 hours ago, Pochie45566 said:

I’ve been working on it. Still cannot figure it out. My AAR seems to be ok. It is slightly open when cold and closes when hot. Water temp sensor checked out ok. Could it be the New afm being out of adjustment?

Which problem?  There was a rich problem, and an idle speed control problem.  I tried to find some AAR pictures but couldn't.  CO had some good ones I think but they got Photobucketed.  The AAR should be at least halfway open if I recall right.  More than slightly.  Like a solid quarter moon's width.

Always best to give numbers also.  "ok" can mean so many things.  Take your measurements at the ECU connector too.  That tests the whole circuit.

[Pochie45566]

So I got around to going through the all the troubleshooting steps in the EFI bible for rough idle and every component turned out okay. AFM resistances are spot on, i removed my throttle body and cleaned the whole thing, made sure my AAR was opening and closing, water temp sensor tests good. Im beginning to be at a loss here. I should also mention that the EGR and BCDD valves have been deleted but it did not impact this issue. 

When I first start the car for maybe the first 5 seconds it ides okay at around 1000 rpm then drops to about 600 where it surges and wants to die. The battery voltage gauge jumps around a good bit also. Then once warmed up it goes back to about 1000 rpm. I was reading that it could be carbon buildup on the intake valves? May need to get the engine decarbonized. Or maybe adjusting the AAR to be open even more? But it already seems to be working fine.

[Zed Head]

Could be that the AAR hose is clogged or connected incorrectly.  If so, it wouldn't matter if it was open or not.  Or there's some other problem so big that the AAR doesn't have an affect.

Any chance you could post a picture of the engine?

[siteunseen]

Maybe have your alternator checked out?  

My Dad swears by that Seafoam stuff.  I've never used it so can't say one way or another.

[siteunseen]

2 minutes ago, Zed Head said:

Could be that the AAR hose is clogged or connected incorrectly.  If so, it wouldn't matter if it was open or not.  Or there's some other problem so big that the AAR doesn't have an affect.

Any chance you could post a picture of the engine?

I wonder if his valve cover hose has a clogged spark arrestor? 

[Pochie45566]

The alternator is actually brand new. I wonder if the belt could be slipping? It does squeak. Only when cold though. Im just looking for problems to all connect here because she runs like a champ once warm. 

Heres an engine bay photo then a close up of throttle body section. My AAR is missing the screws but that shouldn’t affect it. Previous owner lost a lottt of screws ?

Edited November 11, 2018 by Pochie45566

[Dave WM]

does the AFM have the rubber plug still in it. the plug that covers the idle bypass air?

[Zed Head]

Hard to tell.  I marked up a picture of where the hose should be, below.  You could disconnect it and block the hose ends.  Or just clamp it with some vise grips.  If it does the the same thing then it's not having an effect.

You voltmeter is probably jumping around because the idle is so low.  The alternator needs a certain RPM level to create more voltage than the battery.  You're seeing it go from battery to alternator as the idle goes up and down.

What happens to idle speed if you loosen the filler cap, and remove it?  The engine should die.  If it doesn't then somebody has been tuning around a big vacuum leak. Not uncommon.

[Pochie45566]

3 minutes ago, Dave WM said:

does the AFM have the rubber plug still in it. the plug that covers the idle bypass air?

No it does not have that plug, someone has also moved that screw, I can see marks on it 

3 minutes ago, Zed Head said:

Hard to tell.  I marked up a picture of where the hose should be, below.  You could disconnect it and block the hose ends.  Or just clamp it with some vise grips.  If it does the the same thing then it's not having an effect.

You voltmeter is probably jumping around because the idle is so low.  The alternator needs a certain RPM level to create more voltage than the battery.  You're seeing it go from battery to alternator as the idle goes up and down.

What happens to idle speed if you loosen the filler cap, and remove it?  The engine should die.  If it doesn't then somebody has been tuning around a big vacuum leak. Not uncommon.

When removed the engine gets close to dying but doesn’t. It bogs down pretty good though. I’ll test clamping off that hose when I get home. 

[Zed Head]

13 minutes ago, Pochie45566 said:

When removed the engine gets close to dying but doesn’t. It bogs down pretty good though.

Mine dies immediately.  You might have a leak, and somebody has adjusted the AFM to work around it.

Here's another simple quick test - with the engine warmed up turn the idle speed adjustment screw all the way in.  The engine should die.  If it doesn't there's a vacuum leak somewhere.  Here's the screw.  Turn it clockwise until it's closed.

[Pochie45566]

Ok well, it doesn’t die when I take the oil cap off or turn the idle screw in.

i do have a small exhaust leak at the manifold. I notice a broken stud up there also. I’ll investigate for vacuum leaks up there. Also have an oil leak at the oil pan. could be sucking in air. 

Edited November 11, 2018 by Pochie45566