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[greywolf27030]

Okay, the cold is here and fast idle has started working.  Since I got the car running, it has mostly had an idle speed of about 1200/1500RPM.  Occasionally, it would drop to 850RPM or so, but didn't like it.  Now on start-up I'm seeing 2200/2400RPM and after warm-up, the idle remains the same, except it pulses between 2000-2400RPM.  Idle speed only goes down after you shut down and let it sit for a while.  Does this mean my wax is shot or what?  Yes, I know my idle needs adjustment, but after reading the manual, I'm wondering what that means.  But some day when I feel brave, I'm gonna start turning screws, including the one that says don't turn this screw...lol.

Thanks, Jack Byrd

[greywolf27030]

More info I thought of.  On and off the gas is very abrupt.  A touch of gas and the front end comes up, let off and it falls on it's nose.  I have a new 185* thermostat and the gauge reads slightly above the center. 

What do you think, Jack? 

[azgtx]

usually attributed to the ISC/BAC valve

[greywolf27030]

usually attributed to the ISC/BAC valve

Does that mean I need a new/good one?

Jack

[greywolf27030]

In researching my no heat problem, didn't need it til now, I found a small diameter hose going, I think to the ISC, while the two hoses going into the car for the heater were to hot to hold onto, the small hose was cool.  Does this mean no circulation to the ISC so it's getting no signal that the engine is warmed up?  While the pulsing is irritating, my mileage has dropped from 35MPG to 30MPG, gotta hate that.

Thanks, Jack Byrd

[Rocketman]

It does sound like the coolant passage in your idle valve is clogged. This will cause a high idle.

The ECU may be trying to fight it, or there is a mechanical/vacuum feedback loop occuring, causing the oscillating idle. I have had a racing/looping idle like that before when the dashpot was incorrectly adjusted. (pushing onto the throttle plate too much)

[greywolf27030]

Because of personal problems, I haven't time to work on it yet.  But I think I'll take the hoses off(damn and I just put in fresh anti-freeze) blow them out and see what I get.  Maybe I can cure my heat problem and my idle problem at the same time.

Any ideas or suggestions would be appreciated, Jack Byrd

[azgtx]

Those would need to be soaked in something like CLR to dissolve the deposits clogging them up.

[greywolf27030]

I removed the IAC and there was a small clog (1/4") at the lower inlet.  The lower hose was also clogged, replaced it and discovered the lower hose barb (coming from the manifold) was also completely clogged.  Ended up using a drill to clear it out.  Had water flowing out and seemed clear.  No change.     The hose is getting slightly warm, but not hot.  Take it apart again and blow it out?  What do you think?

Thanks, Jack Byrd

PS, did a little looking though the archives and it looks like this is a problem for others also.

[greywolf27030]

Tore into the IAC plumbing again.  The lower manifold bung was stopped up again.  Was easy to unstop this time, the IAC and lower hose were clear.  Removed the hose where it goes into the heater hose and that bung was stopped up also, cleared it.  Filled the radiator with water and used compressed air to force it though still open bungs, result good flow.  What I have now discovered is that the throttle body is stopped up.  Gotta figure how to do something about that for the next installment. 

Jack Byrd

[JJ]

Wow some great sleuthing. Glad I don't have that issue. So what's causing that? do you just need to do a coolant system flush? I think there's a chemical you put in and run it a bit, then rinse very well then refill.

JJ

[greywolf27030]

The material I'm getting from the clogged places is a black granular substance.  I'm thinking it's had a bunch of stop leak put in it in it's past.  The radiator was leaking when I got it.  I've replaced a lot of mechanical stuff on it since I got it, but it was cheap enough that I'm not complaining.

Jack Byrd

[JJ]

Ok you jynxed me. now I have high idle. on the plus side, when i turn on the lights it drops from 1200 to 1000... wonder if it's my idle valve, or if the idle screw is just too high. wondering how to tell...?

[greywolf27030]

Sorry about that.  If it just started suddenly, I'd say it's a problem somewhere other than the throttle body adjustment.  The manual says don't touch the screw, but how do you know what some PO has done in the past.  I hope to be able to remove my throttle body and make an attempt to clean it out.  l live in the south and wonder how important it is for the coolant to go though the throttle body anyway.  If I can't get it cleaned out, I may just bypass it to see what results I'll get.

Jack

[JJ]

nah, new to me so history is unknown.