Cascade Crew

BluFbdy · Posted: Thu Dec 22, 2011 11:23 pm Post subject: hanging idle driving me nuts

This idle issue is screwing with my remote start its seeing it as an over rev so it shuts down anywhere from a minute to 30 seconds, to program the tach learn you have to press and hold the valet button within 5 seconds of starting with the key, it takes the AC voltage it sees and gives it a high and low threshold, problem is my damn car idles how ever it wants, cold it sits around 1500, warm it sits around 700 IF it wants to... another issue is my 5 second window is really small. When I start my car it goes up to 1500 then drops down after about 10 seconds so my tach signal is programmed to 1500 and when the idle drops it sees an under rev and shuts down. I haven't reset minimum air yet and I did it a few months ago when I cleaned the IAC. Another odd thing is that when I'm driving and I press in the clutch and go to neutral my rpms stick around 1500-200 wherever it was when I pressed the clutch, however when I'm sitting still in neutral it will drop with the short delay

I have a Jacobs ultra coil and ignition box that was in the bird when we picked it up, not sure if they work but would it help smooth out my idle? I haven't found any vacuum leaks and I'm stumped
Tips? Info?

MrMike98 · Member Joined: 18 May 2010 Posts: 231 Location: Bremerton

In my case, the bushings in the TB were going bad(held open the blades just a fraction). so i added an extra throttle return spring, which cured my hanging idle issue.....
just one of many ideas to look at.
M

BluFbdy · Posted: Sat Dec 24, 2011 1:09 am Post subject:

Hmm worth a shot, I tried closing the blades by hand under the hood with no such luck, just a side note what exactly is the benefit of a larger coil and ignition pack? I know the idea but I wanna decide if its worth it for me to do it right now

Twilightoptics · Posted: Sat Dec 24, 2011 9:52 am Post subject:

Hotter more consistant spark for a more complete burn.

I'm suspect of the tps.

Get a scan tool on there and see if the ecm is demanding higher iac counts when it idles up, and if so what sensor changes its readings to envoke it.

BluFbdy · Posted: Sat Dec 24, 2011 5:02 pm Post subject:

My tps is non adjustable, I just did the plugs at work tonight because we are dead and they were toast! I remember why I put off doing them my headers are retarded I had to make a socket like a line wrench for the number one and I just cut another one short for the rest, 2 sockets and an hour and a half of my time sacraficed for plugs lol my electrodes were damn near erroded completely so its a good thing I finally broke disband did them header plugs would have been better than the AC delcos I went with lol

Is there a way to bench test the ignition controller and coil? I grounded the coil and put 12 volts to the positive terminal along with grounding the plug with no spark, I'm assuming it needed the controller in place but when I hooked up the energy pak yo power I got the input light to turn on and that's about it lol I emailed them for instructions because Google is useless

aaron_sK · Posted: Sat Dec 24, 2011 5:07 pm Post subject:

You can bench test a coil and ignition module all day and not learn anything. Their failures are almost always temp or vibration related in my experience.

All TPS's are adjustable. Some just need slotting first. Wink

BluFbdy · Posted: Sat Dec 24, 2011 7:40 pm Post subject:

Idk I was hoping to atleast get something outta the system before I installed it in case its junk, I'm getting pissed I just swapped all my plugs and now it has a misfire. All wires are secured all plugs gapped to spec and tight, dizzy is good and it has a miss, the only problem I found was the #8 wire was dried and when I removed it it cracked, couldntt see any arcing but I'm totally stumped here. I need the damn air tubes cut off my headers because the number 8 had to wrap around the back and down.

If I pulled the #8 wire and the idle stays crappy like it is can I assume the wire is toast?

Dewey316 · Posted: Sat Dec 24, 2011 7:45 pm Post subject:

Al Hasse · Posted: Sat Dec 24, 2011 7:57 pm Post subject:

Also, a test light can be used to ground out the spark. A mechanic showed me that trick when I had a bad injector on my V6 and identified the bad cylinder. Poke the grounded probe through the wire boot on the dizzy, if the idle changes, the wire is good, no change indicates a bad wire/plug (or injector if TPI). Only down side is you have a small hole for spark to escape and setting timing can be some fun if you span your hand across the top of the dizzy to turn it (ask me how I Know Shocked

).

BluFbdy · Posted: Sat Dec 24, 2011 8:50 pm Post subject:

Now just throwing this out here by given the condition of my plugs and the fact that I set minimum air not too long ago is it possible its off? When I give it just a hair of gas it smooths out and there's no miss under load, just a consistent chop at idle

aaron_sK · Posted: Sat Dec 24, 2011 11:35 pm Post subject:

A misfiring plug/bad wire/whatever at idle can smooth out as the revs come up.

chevymad · Posted: Sat Dec 24, 2011 11:38 pm Post subject:

Worn out plugs will wear out the wires as well. Causes a voltage increase in order to jump the worn gap, then the wires have to carry all that extra voltage. If they're the stock carbon style wire they wont take that abuse at all.. aftermarkets handle it a little better.

BluFbdy · Posted: Sun Dec 25, 2011 12:59 am Post subject:

They were jegs 8mm red wires, I need to replace them I guess, didn't think I'd get too much life outta them they're house brand lol I was gonna meter them but idk the ohm/ft on them. Looks like I'm doing a quick TuneUp tomorrow if I can, new wires and a timing/ min air check.

Btw; Merry Christmas everyone!

Twilightoptics · Posted: Sun Dec 25, 2011 1:33 pm Post subject:

No probing wires through the wire. It causes future problems!

BluFbdy · Posted: Tue Dec 27, 2011 2:04 am Post subject:

Swapped wires and it runs great now, I ggot smart this time and used the Kevlar (I think or its fiberglass) sleeves from DEI on the back wires, 7&8 both cracked from the heat when I pulled them off, sweet arcing lol I need to get my air tubes cut off and welded inn so I can just route my wires from the top like a normal person lol header wrap o them too lol adjusting minimum airtomorrow if I can, scheduled 9am to 8pm all week....today wasdead however so ifit stays dead ill get paid to screw around with the camaro Laughing

Oddly enough idle has smoothed out...I wonder why lol kidding..... btw but I still need to figure out why the idle hangs, hopefully the min air and iac reset will help, Aaron when you said slotting the tps did you mean like the tpi style so I can shift it around?

aaron_sK · Posted: Tue Dec 27, 2011 7:55 am Post subject:

At some point GM redesigned the TPS's so they just looked for the lowest reading and extrapolated vs. looking for .54V as minimum.

I see a lot of cheap Chinese parts-store TPS's for older cars without slots. Drill or rotozip or small file or whatever fixes that BS.

Another thought: Your minimum throttle might be adjusted too low and the car is being revved solely by the IAC.

Do minimum air as you said and check the TPS with a multimeter or scan tool.

BluFbdy · Posted: Tue Jan 03, 2012 8:58 pm Post subject: