DigitalSynthesis

Okay, I've tried to check the emissions control system (ACV, etc...) and first off... I can't tell whether there is a vacuum or a pressure at the listed solenoids, because of the engine fan! There is so much air moving around in the engine bay I can't tell from a little hose what its doing.

How can I determine if my ACV is working correctly? The damn exhaust is so hot I can't easily get down to it, and that still won't prove much.

Also, I have a high (1500 RPM) surging idle. I've checked the vacuum hoses (put brand new silicone hoses almost everywhere), and recalibrated the TPS (which was pretty out of wack). However, "before" the idle was in target, just rough. Now, its very high, and still fairly rough.

The other problem in similar kind is that the voltages on the ACV connections are like 0.9V and 13V, regardless of engine speed and 5th gear position (I didn't let the clutch out, does that make a difference?). And when I turn the A/C on the idle speed goes UP to 2500 RPM. Needless to say I'm very confused now, since cleaning and reconnecting things has seemed to mess it up more, not help it.

Please let me know where to check, what to look for. I've searched, but its a pretty difficult topic to narrow down accurately. Thanks for the help guys...

DigitalSynthesis

Update: The cruise control cable was too tight, causing the vehicle to idle around 1500 RPM and very rough... I loosened the cruise control, and the idle stabilized immediately, but at 1500. I then adjusted the Idle Speed Adjustment Screw on the top of the throttle body, and dropped the idle to a comfortable 1000 RPM. However, it won't go below that.

I'm still interested in knowing whether my ACV works or not... for the emissions reasons. Help there is greatly appreciated.

HAILERS

Pull the big black hose off the bottom outboard side of the acv. Not the one from the airpump, the bottom big one.

At idle do you feel a bunch of air coming out???? At idle that is.

If you pull the Blue plug off the relief solenoid on the left side of the engine...does the air relieve itself from the bottom of the acv (same black hose). At idle again.

The car has to be fully warmed up for the above. The air should not relieve itself from the acv at idle. When the Blue plug is removed, the air should relieve itself.

The above is just basic to tell if you've ....got the basics.

I doubt your car will pass emissions at an idle of 1000rpm. Just my thought. Does not mean it has not been done.

If the acv does the above write back.

Oh. The rear solenoid is the split air solenoid. The voltage should drop to about 2 volts if the car is put into fifth gear. Matters not if the engine is running. Probably not a player in your emissions checking.

The front solenoid on the acv is the Port Air solenoid and I'll be damned if I can remember right now when it opens and shuts. Not a big player in emissions, but should be made to work if not working. Just put your meter on it and rev the engine and see if you get a voltage drop from the 12v down to approx 1to 2 volts. EDIT: I just looked. At idle it should read approx 2volts, but over 3000 rpm it should read 12v. That means its open at idle and closes at 3000rpm and above. I don't quite remember it working like that, but the book says that.

The major player in the acv is the relief valve in the acv and the switching valve in the acv controled respectively by the Blue and Grey solenoids (solenoids are black, but the elect plugs on them are Blue and Grey.)

DigitalSynthesis

Okay the ACV "works" in the basic sense as you said... in fact, when I removed the blue solenoid the rough idle smoothed out immediately, and resumed when I reconnected it. What does this mean?

I'm checking the electrical stuff now... more when I'm through.

HAILERS

It means the acv has a bad Anti Afterburn diaphram inside it that is allowing unregulated air into the intake.
The anti afterburn should open only during deceleration where upon it lets air into the INTAKE manifold to prevent backfire.

DigitalSynthesis

So, uh... does this mean a brand new ACV entirely? I hope not...

One more thing... I fixed the timing (it was WAY off)... the idle has smoothed out significantly (around 800RPM now, fluctuating only slightly), but the car seems to be afterburning a little bit between 7k and 8k.

After the run the cat was a bit red, but nowhere near the glow it was originally. Am I still running rich or is hitting 8k a few times enough to make the cats glow? I am most concerned now because I still have to pass emissions... its a brand new cat should I take it in now to try?

DigitalSynthesis

* Whoops! Double Post... stupid internet connection *

HAILERS

Yeah. I wouldn't replace the acv over that. It might affect your idle a touch like you describe, but other than that I'd let it go.

The timing must have been your biggest problem. I'd give it another insp try before messing with anything else.

To fix the anti afterburn part of the acv, you would have to replace the whole acv. Not worth it though and its not the cause of any emission failure.

I trust you do have a split air pipe leaving the back of the intake manifold going to a small pipe on the side of the catalytic converter? Of course you do. Right?

DigitalSynthesis

Yes, in fact I do have the split air pipe hooked up OK, at least physically. I have heavy-duty high-temp rubber hose hooking the air pipe to the cat, and what appears to be radiator-type hose between the check valve on the pipe, and the lower intake manifold.

I have heard that I may be running rich, but I have no idea how to measure that or quantify it right now. I hope not to ruin a good cat (and miss out on power) by running TOO rich.

BTW Hailers, thank you so much for attending to this thread... it really means a lot because otherwise I'd be royally freaking out right now about "what did I do to my car!!!"

DigitalSynthesis

I passed the emissions test --- Here's what I did:

1 New O2 Sensor
New Plugs, Wires
Adjusted TPS, Adjusted Idle Speed
New Cat
New Exhaust (not necessary)
Hailers' amazing split air solenoid trick
Good timing
About 1 hour of warmup driving
2 Gallons of Denatured Alcohol in a 1/2 tank


My HC's were at 29, down from 1100, out of 170 allowable. My CO was 0.03% (allowed 1.08%), and I forget what the other stuff was but it was ridiculously low.

Another FC blows away the emissions tests!!

LoSRx7

Where did you get the Denatured Alcohol??

When did you put it in the car?? during 1 hour warm up time, or right before you did the emissions???

Also, anyone have the link on how to get air always going to the cat??? I saw the link before, but i can't find it again.

Thx

LoS

DigitalSynthesis

Hm... I got the alcohol at Home Depot (was a bit pricey but worth it)... I put it in a bit ahead of time (2 gals.), into about 1/4 to 1/3rd of a tank.

The way you get air always going to the cat is to remove a solenoid poppet and spring on the ACV. You simply use a 19mm (I think) wrench on the solenoid in the middle of the ACV (I think that's the split air... can't remember), take it off, and pull out the guts. Save them to put back after the test. Of course put the rest of the solenoid back in there.