Problem was occasional stalling out when stopping, car would simply die when I dipped the clutch. Suspected the IAC; I took it out, filled with WD40 and left on bench (stood it on the electrical connector) overnight.

Drove 90 minutes yesterday in stop-go traffic and did not stall once. So, I think a cheap (but probably temporary) fix.

*UPDATE* - see post dated 10/10/09

Good schtuff, right up there with duct tape and Velcro as mandkind's greatest inventions.

http://www.wd40.com/uses-tips/

Glad it worked! Keep us posted as far as long term use. Might have to respray it a few times but if it keeps you from buying a new one that's always a bonus!

Matthew

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no man cave is complete without these items

Isn't WD-40 silicone ?

I don't think WD has silicon in it, could be wrong. The formula has been secret since they developed it.

It's certainly an excellent solvent. And it's name, Water Displacement 40, is correct. I use on blocks that I wash down after any grinding on (flash removal).

I also use it to mount tires.

I mount tires with it because it drys quickly.

I may try it on my IAC which seems to be sticking but I think I'll hit the IAC with some TriFlo after the WD drys. TriFlo is a teflon lube.

This is interesting...I haven't heard or read about *lubricating* the AIC - perhaps I have missed something. I finally got to mine a couple of weeks ago, and I honestly doubt that it had ever been cleaned. I used Throttle Body Cleaner on both the pindle and the seat as well as sprayed and cleaned the pindle shaft, but I didn't spray any lubricant afterward. There was a LOT of carbon on the pindle and seat and a lot of black cleaner came out from around the shaft. The idle has become a lot more steady but not perfect and this has me wondering if the AIC is sticking a little. Any thoughts/experience?

Pletz - it's pretty common to not retract smoothly or stick even after cleaning it. I read about using WD40 on some ford and honda s2000 forums, so I figured it might work for us, too. DJX was our guinea pig. This could be a good little cheap fix for a lot of people.

just wd'd mine runs better, but what are the signs it is sticking?

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Signs of it possibly sticking are the not quite perfect idle. After cleaning the AIC, I did the minimum idle adjustment as per the book and tested the TPS for .54v. The TPS was reading .533 and I was able to bring it right to .54, rechecked values after I tightened the set screws just to be sure. I am confident the AIC motor is working because once plugged back in the idle moved from the min. set 400 rpm to 650 rpm. and I can hear it clicking when the ALDL is in diagnositic mode.

While idling and watching the on board tach, the rpms will flucuate just a little between 630/640 and 680/690. This is not a serious concern for me and I don't know how perfectly these things (1985 stock) idle in the first place. I also have yet to inspect the distributer/rotor and test the ignition wires - one thing at at time...

OK - so the problem came back. Symptoms identical to before I tried WD40 (stalling out when coasting to a stop and/or pressing the clutch). I have driven probably 750 miles in the last month, so obviously a temporary fix.

At this point I would normally buy a new one, but (in the interests of science and my guru friends) I will try the following:

1. Clean out with TB cleaner
2. Soak overnight with PB blaster
3. Spray with a longer-term lube

Coincidentally, my daughters Eclipse has the same problem, so I am going to do the same on hers.

Stay tuned for results...

I'm going to try some of this if I ever get around to it.

http://www.triflowlubricants.com

I've used this stuff for years, it has teflon in it and is hi temp.

I was under the influence that the IAC should never be hit with solvents.

I would think there are two things that can wear out there... the threading that goes in and out on the screw drive... and the motor itself. I suspect that the screw drive is what fails first, getting goop'd up, which leads to a motor failure.

Interesting, tho... very interesting... if anything, the fix is good whilst one waits to get a new part. If your IAC decides to crap out on a road trip, this fix will get you home or to a hotel very easily.

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6E3-C2-15, Andy, '92 of course.

WD40 is primarily a solvent, so the result of using it on something lubricated is (1) it removes the lubricant, then (2) it provides thin/poor lubrication which evaporates fairly quickly. Especially on something that gets hot.

Never had an IAC apart but I expect there was lube in there from the factory, and after a WD40 soak there isn't.

Can the pintle be unscrewed completely off, or will that destroy it?

Although, really, the cost of a new IAC is what $40? So the investment in time has already probably exceeded the cost of replacement...

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You are absolutely 100% correct. In this case, curiosity has got the better of me, so the time is well spent in my science project :-)

And if nothing else, if you need to get by whilst waiting on the new part, it works.

i was told over at 3rd gen that there is grease in the gears and wd 40 would wash that out, i changed mine 2 days ago, 27.00 autozone, it worked and the herky jerky idle went away...

I don't know if there is grease in there from the factory. Did you inspect the new one to see?

If there is, I wonder what an appropriate substitute would be besides wd40.

Matthew

let's return to the basics

WD40 used on a bicycle chain will clean it and make it smooth but then the WD40 collects dust and falls off leaving the chain to rust.

Using WD40 in any other capacity in place of a lube will do the same whether it is on the 3 year olds bike chain or the space shuttle.

So yeah, you get the benefit if a clean component for a short period of time, but then if you leave it to it's own.....the WD40 will be gone and you have a bone dry component that may be susceptible to oxidation.

I'll not stab at what lube should be used.....but if it a moving part, it should have some lube on it. If you need it to stay dry use the powdered Graphite.

Respectfully John, You're incorrect.

WD does leave a lube film when dry.

When I powerwash a bare block and then coat it with WD, it doesn't rust, even sitting for a month.

From the official wd-40 site (http://www.wd40.com/faqs/):


What does WD-40 do?
WD-40 fulfills five basic functions:
1. CLEANS: WD-40 gets under dirt, grime and grease to clean. It also dissolves adhesives, allowing easy removal of labels, tape and excess bonding material.
2. DISPLACES MOISTURE: Because WD-40 displaces moisture, it quickly dries out electrical systems to eliminate moisture-induced short circuits.
3. PENETRATES: WD-40 loosens rust-to-metal bonds and frees stuck, frozen or rusted metal parts.
4. LUBRICATES: WD-40's lubricating ingredients are widely dispersed and tenaciously held to all moving parts.
5. PROTECTS: WD-40 protects metal surfaces with corrosion-resistant ingredients to shield against moisture and other corrosive elements.

http://www.wd40.com/faqs/

OK - IAC went back in today with a fresh "fill" of silicon lubricant. Interestingly, the first 20 minutes was pretty bad, but things smoothed out nicely and the car is back to non-stalling mode.

I wonder if there is some kind of IAC position 'learn' that the PCM goes through, and the sticky IAC threw it off.

Anyway, enough science experiments, new one is on order. I'll post here once the darn thing starts failing again.

OH - and my daughters eclipse is running nicely too. She does more miles than me, I'll obviously monitor that one as well.

I heard you can spray it on your Johnson to prevent unwanted little ones.

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I imagine spraying it there will prevent a lot of things!!

Don't know about the IAC, but I know solvents are bad for the throttle body's bushing.

Glad it worked out for you.

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Vegetable oil has a lubricating property as well, but that does not mean I should Crisco to lube something.

WD40 is a great solvent, but it is a poor choice for lubricating moving parts.

I'd use WD40 over PB Blaster anytime....and I always have a can....and I DO use it on guns for coating them as you do engine blocks......but not as a lubricant. ( My dad has been using WD40 on his Rifles for ~50 years and they all look pristine, results always go against what the 'experts' state)

Someone mentioned triflow.

So no, I am not "Against" WD40, and if you reread what I said, WD40 collects dust and then falls off of whatever "moving" part you put it on......exposing it to oxidation.

I printed this out a while ago from a CF forum member Vader 86 I think. Some interesting information.
Hope it helps you as much as it did me.

Jim

Throttle Minimum Air Position

Tools needed:
1. Torx driver # T-20
2. Paper Clip
3. Small Punch
4. Tachometer

GENERAL NOTE: The engine should be at normal operating temperature before performing any adjustments. Never rely on the dash mounted instruments for diagnostics and adjustments. The oil pressure and temperature gauges and the voltmeter and tachometer just aren't calibrated accurately enough for diagnosis, but are a relative indication for monitoring the vehicle while driving.

For this adjustment, the transmission will be in DRIVE while you're under the hood. You will need to securely set the parking brake and block the drive wheels. It would also be a good idea to have an assistant hold the service brakes while you perform the adjustments.

In order to successfully complete the adjustment, the IAC air passages and pintle need to be clean. The throttle plates and bores need to be clean as well. If this is not the case, you'll need to remove the air cleaner from TBI engines or the intake air bellows from TPI engines to gain access to the area to be cleaned. A spray-type carburetor cleaner works well for this. Cleaning the IAC passages on a TPI/MAF engine will set a DTC, but we'll be clearing that later. With the engine idling, direct the spray cleaner into the IAC air passages and around the throttle plates. Shut off the engine and continue cleaning the throttle plates by opening the throttle manually. Once everything is satisfactorily cleaned, replace the air bellows on TPI engines. Many times, this alone can solve IAC/idle speed problems.

If this doesn't solve the problem, you may need to remove and clean the IAC stepper motor. If the IAC appears to be clean and functioning properly, continue with the adjustment procedure.

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Idle Air Control Cleaning

You can remove the IAC and service it. Remove the electrical connector from the IAC. Unscrew the IAC unit from the throttle body.

You can gently rock the pintle back and forth and allow the spring to extend it until it comes apart in your hands. Clean everything with lint-free cloths and a mild solvent. Harsh solvents can affect the insulation of the stepper motor coils. It's generally the dirt and buildup on this worm shaft that causes sluggish IAC operation.

When the worm gear on the pintle shaft is clean and dry, apply one drop of clean light oil to the shaft and work the pintle back into the rack gears of the motor by the same rocking motion. It takes a while to get the pintle back into the worm gears, but you'll get it. It is important to get the pintle fully retracted into the housing so that the pintle is not forced against the gears when reinstalling the IAC unit in the throttle body.

While the IAC is out, clean the air passages in the throttle body. The oriface in the TB where the IAC resides is the seat that the IAC valve closes against, and it can accumulate a lot of carbon, dirt, and debris. The easy way to do this is with carburetor cleaner and a small stiff brush.

When everything is clean and dry, replace the gasket if it is damaged, apply a little anti-seize to the threads, and torque the IAC to the proper specs. (13 ft/lb for '85-'89 , 30 in/lb for 1990-on.) Proceed with setting the TPS and minimum air position.

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Locate the Assembly Line Diagnostic Link connector under your dash panel. Remove the cover if it is still there.






Cut and form a paper clip into a "U" shape. Insert the clip ends into the ALDL in the 'A' and 'B' sockets.




Turn on the ignition, but DON'T start the engine. This will force the ECM into its diagnostic mode. Wait 30 seconds to allow the IAC pintle to fully extend. With the ignition still on, go under the hood, remove the electrical connector from the IAC, then turn off the ignition and remove the paper clip jumper from the ALDL. With the IAC pintle fully extended (closed) all idle air will be controlled by the position of the throttle plates. Some manuals indicate that the EST bypass connector should be disconnected for this procedure, while some make no mention of it. While timing is a factor in idle speed, the EST should only operate as a function of engine RPM, temperature, and detonation sensor inputs. To remove all doubt, disconnect the EST bypass connector is your car is so equipped. Some TBI and V-6 engines do not have this bypass connector, and therefore must be set with no regard to the EST system. The EST can be bypassed on some cars by grounding the diagnostic terminal at the ALDL and continuing with the procedure, but the fuel mixture will be skewed to the rich side, affecting idle speed as well. In any event, the minimum air position idle speed range is wide enough to allow for some variations. As always, it is best to consult your service manual for the exact procedure for your system.

Locate the Torx screw on the left side of the throttle body. It may be equipped with a protective metal cap from the factory. This was intended to discourage adjustment. If the cap is present, use a small punch to knock it out. Once the screw is accessible, start the engine and place the transmission in DRIVE. Adjust the throttle stop to obtain 400-450 RPM with the transmission in "DRIVE" on an automatic transmission car, 450-550 in neutral on a manual transmission car, rotating the Torx screw clockwise to raise speed and counter-clockwise to lower speed. Once the idle RPM is set, place the transmission in PARK and turn off the engine.

Re-connect the electrical connector onto the IAC. Start engine. Idle speed should be governed by the ECM at approximately 600-650 rpm in "DRIVE" (for unmodified cars). Idle speed in NEUTRAL or PARK is less significant, and will be higher.



Throttle Position Sensor (TPS)

Tools needed:
1. Digital Volt-Ohm-Meter (VOM)
2. Breakout jumper wires or probes (make your own)
3. AutoXray, Diacom, or similar scanner will replace the VOM and jumper wires.

Turn on ignition, but don't start the engine.

With a diagnostic scanner: plug in the scanner and read the TPS voltage. It should be 0.54Volts +/- 0.07 VDC.

Connect the VOM to the TPS electrical connector terminals �A' and �B'.

With a breakout jumper: Disconnect the electrical connector from the TPS. Install the breakout in-line, between the TPS and wiring harness connector. Connect the meter probes to terminals 'A' and 'B' on the connector. (�B' is the positive connection, �A' the signal ground, or negative.)

With probes: If you have very slender probes on your VOM, you can back-probe the TPS connector while it is attached to the TPS. If you have made probes of large dressmakers pins or a similar item, you can back-probe the connector as well. Connect the meter probes to terminals 'A' and 'B' on the connector.

Turn on the ignition to read the TPS output voltage at the idle position. The reading should be 0.54VDC +/- 0.07VDC. The ideal is the center of the range, 0.54VDC for a stock engine. To adjust the output voltage, loosen the two Torx screws holding the TPS to the throttle body, and slightly rotate the TPS up or down, reading the voltage until it comes into specification. Tighten screws. Using the throttle lever, rotate the throttle to WOT (wide open throttle). The TPS voltage should be over 4.0 volts. Close the throttle again, and then slowly open it to WOT, observing the voltage reading. It should increase progressively and in a linear fashion. If it sticks or jumps or falls off at all while doing this check, the TPS sensor may be failing and could be a cause of stumbling and driveability problems.

After achieving the desired setting, turn off the ignition switch. Remove all jumpers or the scanner and reconnect the TPS connector as required.


Reinitializing the ECM

If you set a DTC during the procedure, the SES light should be illuminated on the dash. This ECM retains DTC data for the previous 50 engine starts, so the codes will eventually be cleared. If you want more immediate results, after shutting down the engine disconnect the negative battery terminal for five minutes. This will clear the ECM of all diagnostic trouble codes. Clearing the ECM also clears any data learned about your engine, and clears the radio presets. If you have a Delco-Loc or Theft Loc II radio, make sure you follow the procedure to unlock the radio protection before disconnecting the battery. This five minutes is also just about long enough to clean both battery cables. Reconnect the battery. When you first start the engine after clearing the ECM, the engine will operate with base parameters programmed into the ECM PROM. These parameters may not be optimum for your engine, but the ECM will enter a Block Learn Mode soon after the engine is warm and enters Closed Loop Mode. The ECM will write new data tables specific to your engine and will eventually rely on those tables instead of the base tables of the factory program. You can expedite this process by driving the car for 20 minutes under varying conditions to allow the ECM to initialize. Or you can wait and drive the car normally at your convenience. The BLM tables are constantly being updated as sensor input ranges change, but the greatest change will occur within the first twenty minutes of Closed Loop operation.

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I'm curious as to why? I use both, and never really noticed one freeing up rust better than the other. Is there a reason I should avoid PB blaster? Is it harder on the materials or something?

Thanks...

Just time and History....nothing more than that. I've never used BP Blaster at all, but it seems that a lot of folks do. I've been using WD40 since the 70s. Pragmatism makes me stick to things that have served me well over the years.

I just bought a new iAC when mine was elrctrically dignosed as bad. Runs great now.From my other forum thread a while back.
"I have been fighting via tuning, an idle problem. Basically I thought due to my camshaft (xe 230/236) it was just causing reversion and my LT1 just wouldnt idle till warm. Also, people reading my logs were saying you have an exhaust leak or a vacuum leak. I chased that forever. So, I wasnt able to run AC in gear at idle, and warm ups were a little tearful due to richness burning my eyes.
According to Data logging, the IAC was working. Wrong, the PCM was working telling the IAC what do do, but it wasnt.
So, I was looking at open loop tune etc for the idle which allot of people do with larger cams.
But I came across this little photo.
[url]http://shbox.com/1/iac2.jpg[/url]
Never thought the IAC was bad per sey, because I was expecting a code, which now I know there is none for IAC in the FSM. Just a resistance check. Well I checked mine, AtoB was bad. Bought a new one and WOW it idles on its own immediately, and even allows AC in gear (Kinda lopey, but the IAC is doing what it can to help idle).
So, lessons learned here guys. Just because you dont have a code, doesnt mean you dont have a problem.

I see WD40 as a sort of one-size fits all penetrant/cleaner/lubricant.

It does everything, but nothing well.

Use pb blaster for penetrating fluid, brakleen for cleaning, and the correct grease or silicon lube for lube.

WD is good on something that a harsher solvent might cause damage to. I agree though, it will cause more harm than good if used as a permanent solution.

I see WD40 as a sort of one-size fits all penetrant/cleaner/lubricant.

It does everything, but nothing well.

Use pb blaster or aerokroil for penetrating fluid, brakleen for cleaning, and the correct grease or silicon lube for lube.

WD is good on something that a harsher solvent might cause damage to. I agree though, it will cause more harm than good if used as a permanent solution.

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Yep, I also use WD as it was designed, to displace water. I use it to mount tires that don't have rim rotation problems because it dries and leaves a film making dismounting much easier, It's also the best thing to remove tire marble marks at the track from your paint.

I lube chains with aaaaaaaaaaa chain lube.

Oh, you guys will get a kick outa this one.....

Yesterday, I helped a kid (My sons friend)with a hand me down bike. The Bike had been sitting outside for a few years. The cheap front shocks were frozen/stuck.

I told my kid to get the WD40, then I sprayed some on the shocks, told the kid that it may take until the next day for the shocks to come loose.....

Another kid that was watching (14 years old or so) He grabs the can and looks at it...."What is this stuff"

I looked at my kid.......His mouth was open as well.

The kid had never heard of WD40

Symptomatic of growing up in Irvine....no one here bothers to try to work on anything themselves.

He probably said the same about the screwdriver and the allen wrench. "What is this stuff?"