View Full Version : Idle issues 88 ix

03-16-2009, 03:30 PM
On cold or warm start up it will hang at about 1500rpm for about 20 seconds, then drops to about 1000 and stays there hot or cold.
The odd time(every 30 seconds or so) it will stumble a bit and drop to 700 momentarily, then back up.
Also feels slightly underpowered.
When I blip on/off the throttle just a tiny bit, it will go up(lets say to 1500rpm) and will hang there a few seconds before coming down. This will happen repeatedly.
Engine revs up to speed no problem.

Looked for vacuum leak, nothing obvious. Has new plugs and wires, alternator and battery.

Looking to get this damn idle issue sorted soon. Whos got ideas?

03-16-2009, 03:38 PM
Did ya clean out the ICV good? If you shake it the thingy inside should move freely.

03-16-2009, 04:55 PM
Actually having a similar problem on my iX. I adjusted my idle screw to bump the idle up, and its higher (mabye too high), but now it idles very strange. Greg told me the TPS probably isn't lined up, but i feel like i probably have more than one problem.

03-16-2009, 06:26 PM
ha, maybe
ok, im going to go shake the shit out of my icv

03-16-2009, 09:46 PM
icv seemed to move freely. any other ideas?

03-17-2009, 07:57 AM
how cleans the intake system? Get some intake cleaner in an arosel, spary the can into the throttle body with car running, that will clean off sensors, valves, plugs ect. The sparys like $10 a can at the GM dealers (its all the same product at every dealer) Takes about 30 minutes to do the procedure, and see how she's idling. This is basically what the dealers charge $150 for - intake cleaning gets all the carbon and oil build up outa the intake, so if anything ius gunked up this should help.

03-17-2009, 08:39 AM
you think maybe my tps is messed up?
What about my temp sensor too? The cluster gauge shows cold thru warm as it should, but the idle speed does not change when its warmed up.
Replaced the sensor for the gauge recently but the other sensor is untouched. I am sure there are hot/cold resistance values for this sensor somewhere. Anyone know where I can find it.
I think it might be running a slight bit rich too.

03-17-2009, 12:52 PM
ok, did a bit of a cleanout of the intake, and changed the throttle cable.
When i first started it up, it sat at 1500rpm for about 20 secs, then went down by 50rpm or so every 5 seconds, till it started to misfire and chug. I held it at about 2500 for a minute and now its idling smoothly at 1100, barely stuttering but still high and its currently at temp(or just below).
Just checked the resistance at the blue temp sensor(car off) and it was at 380 and climbing slowly as the car cools.


03-18-2009, 03:03 PM

03-18-2009, 04:56 PM
what plugs are you running?

03-18-2009, 04:57 PM

03-18-2009, 05:35 PM
I'm using the champion coppers from Napa.

i guess seafoam may be in order here. I can pick this type of shit up where(Napa, CT, Dealer)? What brand or does it have a name its known as?
I've seen it done on youtube several times, im not terribly worried about how to do it. just need to find out what and where.

03-22-2009, 12:29 PM
Seafoam is the brand. I believe that carquest sells it, not 100% positive though, I haven't been able to find it anywhere else. You can substitute other things for seafoam, water will also work (although maybe not as well), and some people use ATF too. GM sells an upper combustion chamber cleaner that is similar I believe.

03-22-2009, 03:26 PM
i picked up some Seafoam brand Seafoam from PartsSource for $12 Will be trying it tomorrow.
On a side note, idle is definitely smoother on 91oct, duh, but still high at 1100. Swapped ICV with another known good one and same results.
Waiting on results of Seafoam.

03-28-2009, 06:51 PM
seafoamed it today, it was clean, no change at all.
will be swapping AFM later tonight or tomorrow morning to see if it helps.

04-10-2009, 11:44 PM
swapped AFM and same result. Also replaced dist cap and rotor.
Still the same high idle.
Could my timing be off?
still havent changed the tps or ecu

1'M Seriesus
04-11-2009, 11:33 AM
what are the exact symptoms of your engine,

has your check engine light or anything is it stumbling, lack of power? poor fuel economy? noise/vibration?

04-12-2009, 09:06 PM
no check engine light. stumbles and vibrates only slightly at idle. lack of power <2000 rpm. Smooth and pulls hard above that. I haven't been driving it enough to note fuel eco.
List of things ive done:
Plug wires
Dist cap
Dist rotor
Coolant temp sensor(for cluster)
Throttle cable

I think all hints point to timing.

1'M Seriesus
04-13-2009, 09:59 AM
i'm thinking either bad gasoline, dirty injectors or intake and vacuum leak?