Suzuki Forums banner
Status
Not open for further replies.

Surging/Bouncing idle/HIGH idle

15K views 14 replies 6 participants last post by  Exarach  
#1 ·
Hi there guys!

Thanks for tuning in to round 2 of "Whats F*cked up?" Here on the WFU, we have a problem with idling today! (Again)

Last night, I replaced the vacuum lines, and the VSV. The previous user had bypassed the front (red) solenoid, and I was experiencing a bit high of an idle on start, 2200-2300.

WELL. That son'abitch idles right around 3100 now!

I drove it to work today and thought the car was going to explode.
3100 on start up, and then it would "Bounce"

-After running for 30 minutes on highway speeds, the Rpm's began to bounce between 1300-1900 on idle.

I have looked at the Throttle assembly/Throttle piece, and it is the next item I was going to take a crack at.

I also believe the thermostat is shot, as I get little to no heat even on full blast, and the gauge has never moved beyond 1/4 max.

I am going to replace the thermostat tonight.

Anyone have any ideas?
 
Save
#3 · (Edited)
So, it COULD actually be the thermostat? Maybe its stuck......IDK, the engine does get very warm. I will let you know how it goes. (Unless someone chimes in and says it is something completely un-thermostat related haha)
 
Save
#4 ·
hi I have a 92 16v 4dr . I did the thermostat when it was apart I replaced the coolent temp sensor for the computer . the intake in the water jacket was all built up with scale (never changed or flushed ) the end of the sensor had a 1/8" of scale on it . don't know if it will help you but it was not expensive and I was there any way and it seemed to idle more stable after
 
#5 ·
The temperature gauge on the dash is little indication of anything - mine has sat on 1/4 for 16 years. But you should be getting GREAT heat in the car - which is an indication of engine temp. If you are not doing so, as Aqua says, then your car is not warming up to proper running temp, and the ECU is continuing to try to get the car warmed up, by running rich. Test your thermostat/replace, etc. and if possible get an IR thermometer pointed at the thermostat housing - your temp should be 170+F. Make sure that the thermostat is seated properly in the housing - there are two different types of housing and on 91+ it should be the 4mm well, where you will need a 5mm rubber gasket around the thermostat (not usually included with the thermostat, either), so that the thermostat is not floating around the housing. The bleed hole in the thermostat should face toward the radiator, etc.

Edit: and you should put your car's specs into your signature, so everyone knows what you're driving....:)
 
Save
#6 ·
I realized that about two minutes into ye post! haha, I put a standard thermo on the housing last night, and believe this to be an issue. it was right around 150ish, but the sensor was at the correct Ohms/temp. I have already boiled a new thermo, and will be installing this afternoon.

We are currently controlling the idle with the two screws on the throttle body, and moving the TPS, not sure if the ISC is working though. Have to test. Still idling at 1000ish when warm, but much better vs 3300.

Heat in the car is give or take. Takes forever, and only gets warm around the middle vents, placing my hand over them.

I hope a new thermo fixes this.
 
Save
#7 ·
Sounds EXACTLY like my old problem. Im not saying this will fix it, but to find out if it is your idle control sylendoid (it was for me and I had exact same problem) you can remove the ics, cover the inputs and reattach it. if it doesnt clean up the high idle you can just remove whatever you used to cover it. It worked for me but it also elimantes the proper high cold start idle, you will have to give it some gas or it will die.
 
Save
#8 ·
The ISC was on my list of issues to check tonight. I am actually stoked to hear you had a similar problem fixed by a lousy solenoid issue!

If this is the problem, that would make me ecstatic.
 
Save
#11 ·
Did you 'burp' the cooling system when you changed the thermostat? Made sure you had the proper gasket? The heat in this car should be GREAT - nothing less. Your 1990 ISC can be removed from the car, and cleaned with carb cleaner so that the little plunger inside is free - bench testing it with 12vdc will show that the plunger vibrates, etc. Although, frankly, it would appear to be doing what it should be doing, if it is bumping up your idle with a load on. Just adjusting your idle with the throttle screw is only masking a problem. Idle is a symptom of a problem, not the problem itself. And if your car is not heating up properly (and you don't confirm this with an IR thermometer or similar) nothing will help your high idle, as the ECU will continue to cause the car to run rich in an effort to warm the car up.
 
Save
#12 ·
Hi Bex!

Yep, I know its masking the larger issue, I just have to find what that is haha.

I believe the ISC may be working, but that rattle has me concerned.

IDK, I used the gasket and thermo provided by napa, it looked good, and all went together fine, I will test it tonight, I haven't burped it yet, as I just let it run for about 1/2 hour and didn't see any noticeable coolant drop. I will try tonight. Good news is my gauge is working, actually varied a bit last night.

I don't know, the thermo that was in the car was installed with the air bleed backwards, and was an offset model. (Not perfectly centered) and the one I put in was, but it lined up 100% and I couldn't see any place where it would change the function. Same temp (180)

I believe this guy just needs a good overall cleaning, it sat for a while prior to me owning it, and, while I have some plans for the inside, its going to have to wait till the engine is in good order. I think the 150,000 has something to do with it as well haha.

I will keep hitting the FSM till I can find what is holding the idle open.

Any tracker genius's or Geodudes in the phoenix area? :D
 
Save
#14 ·
Ktravis, you need to start your own thread with your own specs and info, rather than piggybacking on a thread.
 
Save
Status
Not open for further replies.
You have insufficient privileges to reply here.