What's up with my idle?

clinerg · 11-28-2014, 07:52 AM

Hello Pelicans,

Weird idle issue developing. It doesn't do this all the time. Any ideas what might be the cause?

https://m.youtube.com/watch?v=xPOGBPAPyb4

prebordao · 11-28-2014, 08:26 AM

probably mixture too rich

DRACO A5OG · DRACO A5OG's Garage

Sticky Idle Control Valve (ICV)

When it does it again, pull over, leave the car on, place eBrake, pop lid, and tap the ICV with the handle of a screw driver.

If it clears up, you need to remove and clean it out with a non-residue carb cleaner until it comes out clean and shoot a bit of silicon based lube into it and rattle it to insure it is not sticking.

Also check the ohms are withing tolerances.

Jim

prebordao · 11-28-2014, 08:51 AM

Forgot about the ICV. I don't have those "modern" contraptions...

Discseven · Discseven's Garage

+1 Jim.

I ended up removing the ICV to... clean valve area, tighten 3 contacts, replace clamps on hose connection to intake plenum. Problem solved.

clinerg · 11-28-2014, 09:05 AM

Headed over to my shop in a little and will give that a shot. Thank you

D@vid · D@vid's Garage

Found this

m.youtube.com/watch?v=8TcAzqKxWgY

clinerg · 11-28-2014, 12:59 PM

I did some investigating.. That's about all I got accomplished before the cold weather got to me. I manged to get my pinky finger into the ICV. Lots of scum in there! I also used my last squirt of carb cleaner while testing to see how much I had left. I'll need to regroup and try again

Steve@Rennsport · 11-28-2014, 01:21 PM

Quote:

Originally Posted by clinerg

Hello Pelicans,

Weird idle issue developing. It doesn't do this all the time. Any ideas what might be the cause?

https://m.youtube.com/watch?v=xPOGBPAPyb4

Hi,

Sorry to hear of your troubles, but these issues are generally pretty simple to resolve.

For the benefit of others who may read this, I would strongly encourage anyone asking for assistance to please mention what car, year & model you have, especially if you want a professional to help you. In this example, I really have no idea what year car we are referring to which makes it quite challenging to offer anything constructive.

Its also helpful mentioning details about when the engine was last tuned up.

I'm always happy to offer assistance, however I need a LOT more information in order to do that and this post is somewhat lacking in that regard.

clinerg · 11-28-2014, 01:40 PM

Hi Steve,

Good point. The car is a 1984 3.2. The engine was rebuilt in 2003 and has 4000 miles since. I do not know the extent of the rebuild however. The PO did mention that hotter cams were put in but I do not know the details on that either.

As far as a proper tune up, I'm not sure when that was done last. I purchased it about 3 months ago. I've had it to a mechanic who changed the oil and gave the car a general thumbs up. My file of receipts from the PO seem to only indicate oil changes since the engine rebuild.

George

DRACO A5OG · DRACO A5OG's Garage

His video shows "3.2" so I deduced it was 3.2 with ICV

If the car sits the gunk will get thicker. Yes, our babies loved to be driven. rest = rust

clinerg · 11-28-2014, 01:47 PM

Here is as much detail on the rebuild as I have. It's all Greek to me.. But I'm learning.. Slowly

Steve@Rennsport · 11-28-2014, 09:45 PM

Quote:

Originally Posted by clinerg

Hi Steve,

Good point. The car is a 1984 3.2. The engine was rebuilt in 2003 and has 4000 miles since. I do not know the extent of the rebuild however. The PO did mention that hotter cams were put in but I do not know the details on that either.

As far as a proper tune up, I'm not sure when that was done last. I purchased it about 3 months ago. I've had it to a mechanic who changed the oil and gave the car a general thumbs up. My file of receipts from the PO seem to only indicate oil changes since the engine rebuild.

George

Hi George,

Ahhh,..thank you VERY much.

Several things can cause idle surging so these are the things to check out very thoroughly:

1) Oxysensor and associated wiring.

2) Idle stabilizer; clean with carb cleaner and make certain its working, per the factory manuals.

3) Check the intake manifold for any small vacuum leaks. False air isn't metered so that causes problems.

4) See if the DME has a factory or aftermarket chip in it.

5) Check head temp sensor's wiring and connectors to make certain you have complete continuity. I've seen issues with the M/F connectors.

This will get you started and please let me know what you find.

Hope this helps,

stlrj · 09:39 AM

Classic symptoms of base idle set too high. Try lowering it and observe how steady it becomes...like magic. The opposite is also true. You can make any 3.2 with a steady idle hunt like that by backing off the idle air bypass screw.

Cheers,

Joe