I took my 1996 del Sol si (D16Y8) into the dealership to have them look at my engine because of an idle problem.

They called me stating that they had fixed the idle problem. They proceeded to explain to me that the idle adjust screw has some type of sealant( they didn't even have a word for it) over it to stop owners from messing with it. He even told me that the screw should not be touched, and this was the reason the sealer was over the screw..

So apparently they adjusted the idle and replaced whatever seal they claim is missing, and it fixed the idle problem.

Since this is Tech and not GDD, I'm wondering if there is any merit WHATSOEVER to what he is telling me. I have a feeling that i have a vacuum leak causing the idle problem, and them adjusting the idle just lowered it so it doesn't lope erratically anymore - NOT A FIX in my book.

 

The screw that stops the throttle plate is NOT a field adjustment. That is pre-set at the factory so the plate closes completely but doesn't slam against the sides of the throttle body, and it should be left exactly there.

There is an air bleed screw and an electrical valve to let air around the throttle plate when it is closed completely at idle. It is not like carbs that hold the throttle plate slightly open to idle.

Do not expect the stock dash tach to be accurate at idle speeds. If it doesn't surge up and down and doesn't stall, idle is probably being held at the correct rpm by the ECU.

 

Is OP talking about the air bleed screw or the other one? Lots of guys on here reguarly recommend adjusting the screw and i'm wondering if they're talking about the one that should or shouldn't be touched? MK3, are you talking about the coolant air bleeding screw?

 

I'm referring to the screw near the map sensor, not the throttle stop screw.

 

The big flat-blade screw (actually it is a valve) near the MAP sensor is the proper one to adjust. Though as others pointed out, adjustment is seldom needed, it should not have a seal on it.

 

After step 5, it states if the idle requires adjustment, to remove the cap.

 

Umm...you dont' need to adjust the idle to remove the cap, you need to remove the cap to adjust the idle.

They are correct. Its not something WE should be tampering with BUT because we have multiple guides, the FSM, its possible for us to adjust it ourselves.

 

My idle screw was covered with a plastic cap.

The idle screw was meant to be adjusted to bring the idle to spec, so I have no idea what the tech was talking about. Sounds like pure BS to me.

 

My interpretation could be wrong, but I think he was telling the OP to "not dick with something you don't know how to fix". I see these professional phrases before, but I usually challenge it.

 

Tony, here's the quote:

 

It's not a sealant, it's more of a painted on stripe to show if it's been tampered with. It was there from the factory on my D series TB. It's kind of like the tiny stripe that gets painted onto those tiny screws with electronics, so that if you **** with it and try to make a warranty claim after breaking it, the company can prove that you did something you shouldn't have.

Why a car needs this, I don't know, but that's the why behind it.

 

This is easy to answer, so users similar to W95 don't "tinker" on their new car then go to the dealership for "warranty work" on their new car now that it's not operating properly.

It's really only for when the car is still under warranty. So after warranty work will get the same treatment if the shop warranties their work. They need to know you didn't tinker with it after them. If you have, warranty void.

 

That's just the thing, though. Unlike it's use in electronics, where removing a screw could quite literally fry the device (screws on PCBs are frequently used as grounds), for the idle adjustment screw, you aren't going to physically hurt your car by moving it. You might make it idle too high, or too low, but it will still be limited by the size of the orifice it feeds, and I highly doubt it'll feed enough air to blow up the engine.

The throttle plate set screw, however, I totally get that. Tighten that down too much, and RIP clutch/clutch packs.

 

If you notice, it's typically just about every bolt/screw in the engine that can adjust or seal something.

There was the paint on the banjo bolt on my fuel filter.

At the lube shops they put tamper seal on the oil plug bolt and the oil filter.

Customer comes back about no oil and the tamper seal is broken, no warranty approved.

The idling high or too low to where it stalls is exactly the same thing. Mechanic gives the car back running near perfect, 3 days later customer comes back, car is idling funny, I want my money back or at least a partial refund... Tamper seals show tampering, claim denied.

It's all warranty orientated.

 

Makes sense.

 

"I'm wondering if there is any merit WHATSOEVER to what he is telling me."


It is a sealant. Not sure if every car has come out of the factory with the grey goo on the idle speed adjuster screw, but that's what we called it when I worked at the dealer. Yeah, it been a few years, but I remember doing a new car make-ready on a Civic and found the idle speed out of spec... so to the book and adjusting I did go. Shop foreman saw what I was doing,aAnd gave me a bottle of grey goo (about the size of a Visine bottle) to dab on the screw to replace the stuff I scraped off the screw to adjust it.


Don't know if they fixed your car, but there is truth in what they said.


lrhtech

 

concur

 

So I have my vehicle back. Only thing the tech claimed to do to fix my idle surging was adjust the idle screw back to "factory position" and replace the tampering goo. The surging itself is gone, but I'm not 100% sure he actually fixed the problem.
Car still doesn't run 100%; while driving under normal conditions, the car will buck significantly. This has only happened about 3 times so far, but I have not experienced this symptom since before I replaced my IACV.

 

Hmm...check your tps. Does this happen at low rpms?

 

Fairly low rpm. Around 2.5k.
TPS was my first suspicion as well. Will test and report back.

I know I'm looking for a drop in voltage, but how much should raise a flag? .1v? .4v?