Are these “ norm “ idle parameters? Just wondering vs other 3.2s
 

I think my car runs great, PO was a mech, she doesn’t leak, and I feel it drives and sounds great. But, I have no place to compare. So here’s a 20 sec clip of me at idle and reving till 3K.

SW chip

Car ran for 30min and is about 2c or 34F. My oil temp is always cold but..it’s cold out.

6k it will be about 4.2K

https://youtu.be/eSzSYjkMFJo

Sounds great!

1200 idle is too high if that's what you're asking

It sounds exactly how I expected it to and the oil pressure looks pretty normal for a car that's still warming up.

It’s only ran abut 20 min not about 3500. She idles smooth at 1100-1200. It’s cold out. It’s an 86.

So what should it be? And why is it to high? Again, it’s cold here.

factory idle specs say 850 - 880, others recommend 880 - 920.

Assuming your idle control valve is clean and functioning properly and the idle position switch is working correctly, you may have a vacuum leak or the idle is just not adjusted right. You can find vacuum leaks easily with a smoke test. Lots of places where a vacuum leak can manifest itself but common areas are the vacuum lines and the large intake boot at the AFM, hoses for the brake booster, intake manifold gaskets and possibly the intake spacers. Once you have ruled out any leaks, there is a procedure to set your base CO2 and idle so it's within factory specs.

just warm-up the engine and adjust you idle with the screw..that is all

ivan

Something tells me he (Hotshot) has not a clue of what an idle air bypass is, what it looks like, where it's located or what it does. These instructions might be assuming too much...


Cheers,

Joe
87 Carrera

Well, interesting enough, I’ll say sorta... I know about the screw behind the yellow plug that’s adjustable, called a bypass screw in Porsche service manual, and I have read to jump the port on the right, as I have a shop manual from Porsche.

But what I don’t fully understand is this... there’s this adjustment, which only seems like part 1... which says 800-840 and to make sure to do it at 15c to 35 c... I said it was at the freezing mark when that video was taken.

Then there’s part 2 that’s dealing with the air flow sensor on USA cars, and then there’s the fact that I have a SW chip, and a Cat delete...

And then there’s this CO tester thing.

So, I’m trying to learn what parameters and steps need to happen.

Is it as easy and jumping a pin out and moving a screw, or more involved.

I come here to learn.

You engine isn't screaming hot, but it's warmed up, so I'd say your idle is fast. Ambient air temps shouldn't have much to do with idle speed once things warm up. My car idles lower than that from a cold start at 60F.

High idle speed w/ a Motronic engine is almost always the result of some other issue. Generally it's not something that you need to adjust -- once you fix the issue, it idles right.

Intake leaks (def. the most common), bad/misadjusted TPS, bad cylinder head temp sensor, bad O2 (maybe?) or an issue with the ICV. Could also be a binding issue with the cruise control cable or maybe the throttle cable isn't allowing the throttle to fully close.

Basically, you're either getting excess unmetered air in the system, or the ECU thinks that the engine still cold. Or maybe the A/C is stuck on? Can't remember if these cars have an idle-up when the air conditioning is on.

Definitely don't dick around with the AFM adjustment screw unless you know for sure that's your problem. A classic sign that this is the case is if you see evidence that someone else tried to adjust the screw.

I'd start by popping the engine lid and taking a look around. Grab an (unlit) propane torch or a can of starter fluid/carb cleaner and poke around for intake leaks.

Interesting. I took out the cruise module under the dash but that was electronic. The PO said he never used it and wasn’t sure it worked, that testing it could lead to it getting stuck on. Until I understand the system, I thought, be save, pull the plug. The lines are all hooked up.

Looks like my idle screw has a little yellow guard. I think I moved that while cleaning but thought it was a guard.

What’s this torch and starter fluid deal?



http://forums.pelicanparts.com/uploa...1587267924.jpg
http://forums.pelicanparts.com/uploa...1587267924.jpg

The propane torch/starter fluid are just ways to find intake leaks. If you hold an unlit torch with the gas on to various parts of the intake, you'll hear the idle rise if there's a leak that's sucking in propane. Same principle with spraying starter fluid.

What I'd do is search for one of the intake leak threads -- there are a few of them on here, and pretty comprehensive, both with common leak locations and ways to find them.

One thing I'd try -- while the engine is running, pop the oil filler cap off and listen to hear if the idle rises at all. If not, it's definitely worth checking some of the typical intake leak culprits.

I actually just fixed one on my car -- the PCV hose reducer right behind the electric heater duct fan (top left, attached to the plastic duct w/ the stickers on it) was cracked.

..your problem is the plug was never (most likely ) ever removed ...so the idle was never adjusted..like i said remove it-it will brake - and then adjust your idle..it is nice that you are reading some stuff but sometimes too much reading is too much;-))))

The best thing you can do is put that shop manual away since it's designed to confuse and intimidate with all the rocket science instruction that you will never understand anyway. So please put it away and simply put your little socket on that bypass screw and turn it in until your idle speed goes down to where you want and you're done!

Otherwise you will get so frustrated that you will give up and end up taking it in to a pro just to have him do what I just told you and then pay him for something you could have done in two seconds.


Cheers,

Joe
87 Carrera

Not so fast... turning the idle adjust screw alone won't change idle as the IAC will compensate for the change and you'll be back to square one. Have to take it off line by jumpering the connection on the left side of the engine bay first. Search this forum to locate it and find the correct pins to jumper it. Also, find out what the correct idle is supposed to be for that SW chip. Personally, I wouldn't fool with it until things warmed up and you can get a true idle reading .

Some good and some bad information here. We need to back to the basics.
- The idle on the 3.2 is not "set". It is 100% controlled by the computer. (DME)
- The early Motronic DME has the idle programmed at 800 RPM.
- The later DME chips have the idle set at 880 RPM. (The Steve Wong chip and 28 pin chips should have the 880 idle.)
- The engine isn't operating in "closed loop" at idle so you can't get a high idle from an O2 sensor issue.
- The DME detects that it should idling only when the idle position sensor is closed. If it isn't closing the engine will not try to idle.
- The idle speed is controlled by the air allowed in by the Idle Air Control valve. This valve must be operating correctly for the DME to have any control over the idle.
- Any air added from an uncontrolled source will raise the idle when that quantity of air exceeds what the IAC valve would have added.

So you have really limited choices: Vacuum leak, IAC issue/failure, Idle position switch issue/failure, or some sort of previously unheard of error inside the DME.

(And the first person mentioning the DME relay gets shot.)

Yes, if I remove the oil cap, it lowers. As soon as I put it on, it revs up a little.

Thx. Is there any real concern or damage with an 1000 rpm engine?

I follow. I’ll just drive the car for now, while I learn about all this ( I have the jumper info ), and I’ll wait till it warms up. It will be 20c here soon.

I love the help on here. Really appreciate everyone.

d +1 Also, the throttle valve has an adjustable stop that may have been fooled with by some prior owner. The throttle is supposed to return to almost completed closed (IIRC the spec is .005" open as measured with a feeler gauge). You can make sure that the throttle is closing enough by disconnecting the plug from the switch on the throttle bell crank, and using a test light or ohm meter to verify that the throttle is closing enough to energize the switch. This little micro switch brings the idle control valve into the system to dynamically control the idle speed. You may find that someone has adjusted the throttle stop as a means to set the idle speed. On my 86, I had to carefully back the screw out until the switch would reliably complete a circuit when hooked up to my ohm meter. If you find you have to adjust this, there is a little lock nut that has to be loosened before the screw will turn. I think it is 6 or 7 mm.

[QUOTE=Quicksilver;10830336]Some good and some bad information here. We need to back to the basics.
- The idle on the 3.2 is not "set". It is 100% controlled by the computer. (DME)
really??

How about this adjusting the idle speed;-))))) of course there more to it but yes it is a manual idle adjutment;-)

Ivan

http://forums.pelicanparts.com/uploa...1587314271.jpg

That adjustment is set by the factory, which is why there's a plastic plug over it. You really shouldn't have to play with it.

Always hate to see when that plug (or the one on the AFM) has been removed. Typically it's a sign of a kludgy mechanic. This isn't a carburetor. Those factory settings should be the absolute last thing you mess around with, after you've tried everything else. Not sure where that repair manual picture came from, but I've worked on a bunch of Motronic (and later) engines, and that's never the way to set the idle. (I don't see it in my Bentley manual, FWIW).

But waaay before doing that, I'd check the usual suspects for high idle. These cars can develop intake leaks all over the place -- the manifold gaskets, the PCV hoses, the oil filler breather hoses. Big temperature swings and freezing cold temps only help the rubber stuff crack and split even faster.

The intake leak I had only really manifested when it was cold -- it was a hairline split in a rubber fitting. I think once the engine warmed up, the rubber expanded enough to seal up the crack, and no more intake leak.

monkey ...you really made me laugh.....this page is from Porsche factory specification manual...other than this i cannot comment on your analises;-))

Ivan, the kludgy mechanic;-)))))))))))

here is an answer to your above question..http://forums.pelicanparts.com/uploa...1587324848.jpg

people who did this book know something about adjusting 911 Carrera engine idle;-)

That’s the book I have. Or a PDF of it.

Hotshot..you're going the right direction;-) just do not overthink it...
Ivan

There isn't any "damage" per se, but it isn't idling. Getting it to run right shouldn't be that hard and it should run right.
If you are in an area where they have a smog test it will most likely fail if it doesn't drop to idle.

_______________________________________________
There is an obvious value to having everything set within the intended range that they were engineered for. The idle set procedure you mention has you disable the computer's control so you can see what the underlying adjustments are.
When they are adjusted correctly you know that the butterfly is passing something around the intended quantity of air so no matter what kind of conditions you are running under (altitude, temp, gas quality, etc), the DME's control of the IAC will be able to keep the engine running at the correct idle speed.

The manual idle setting should never ever have to be set unless the throttle body has become incredibly worn and it is pulling air around the butterfly shaft. Even then the original setting should still be fine because the DME has so much latitude in controlling the idle.

But adjusting the mechanical idle stop to compensate for a physical issue should be a pretty obvious mistake. Fix the issue. Don't compensate for it.
(But I have to say that because he doesn't know the cars previous history it is possible that someone monkeyed with the idle set screw and helped create the problem.)

i will leave it as this Wayne........way overthinking ....it hurts....the OP issue is very simple than what you suggest here;-))

Ivan

No Cat and an SW chip.. no smog tests where I am.

I’m wanting to go slow and learn this car inside n out. Would I like it in spec? Of course. At the same time,
While it’s cold Here and I am learning, I won’t mess with
Stuff I don’t fully understand. I have to also check how the SW chip effects it. The PO gave me all the old parts and a O2 sensor ( I have a new one, and the OEM Chip ).

A value all the points and an don’t want to reinvent the wheel. I like to keep it simple at first.

I want to know my car inside n out. It’s ranges, sounds and systems. Lots of reading and looking at stuff.

So keep it coming. I just don’t want to run the car and damage anything.

Is there away to check my Tac is accurate? Could be gauge..?

hotspot sound ok but the video cuts off right when it is coming to the idle make a another video even of the engine...that would easier to see if your RPM is real..
Ivan

Will do. Last night I took it out for a 30min test drive. It was 34F. While idling I popped the oil cap off and noticed it dropped about 180 of the tach.

Here was play by play. Below the pics is a video I took of it idling the first time I took it out this year. When it revs up, that’s me pulling the cable.


Just after starting, but I took the oil cap off/on , tack went lower value 1200 to 950. The audible engine sound came back to where it was, but the gauge showed lower.
http://forums.pelicanparts.com/uploa...1587387993.jpg

After easy driving for 15 min it’s lower than normal but up a little. Bout 1050.

http://forums.pelicanparts.com/uploa...1587387993.jpg


Then after a Hard run, hard turns, braking, etc, at a stop, it looked like it crept up to wear it normally is, just below 1200.

I’m wondering if it’s fuel cap?


http://forums.pelicanparts.com/uploa...1587387993.jpg

https://youtu.be/x2H3Pr1kmEg

ok sounds good besides the needed valve adjustment and loose alternator belt..Really do you self a favor remove that yellow cap and turn the 7mm screw about 1/2 turn and you will be allset;-)

that is all i`d do ..........and enjoy the beast;-)))

Ivan

Wait my belts loose?

yes, your alternator belt needs to be adjusted;-)

I need the P209 wrench, only part of the tool kit I don’t have. The book says it should press in about 5mm. That’s about it. It’s a Goodyear belt with a lot of text printing. I’m wondering If that makes it look wobbly.

A little tightening, surly can’t hurt.

Here’s another vid I took, with the cap on n off.

Went for a very spirited run, and she goes good. It’s just hard when you cave no comparisons.

https://youtu.be/I4sqwoH8Fmw

ok,the tool is kinda good to have look around the net and get one...to adjust the belt..your idle seems ok ,did you do any adjustments?..this is my 911 not really all the way to idle standard..but it will give an idea your are ok;-) i keep mine around 950 and i like it that way...
https://www.youtube.com/watch?v=Out_PKGkYYY

about the alternator belt adjustment..it looks like you do not have enough shims on the shaft...there have to be 6 of the shims no less or no more your is less..
https://cdn4.pelicanparts.com/techar...small/pic2.jpg

Thx. I didn’t do anything yet because I want to Check for leaks. I pulled my cruise control module because my PO said he never used it, and something to the effect it stays on. I’ll test the plug pins for something to do, but I am interested in learning and doing a vacuum leak check.

Then if nothing happens I’ll move the screw but mark it first so I can move it back. There’s NO Way I’m moving the CO screw as I lack the knowledge and don’t have a CO meter.

I checked the ICV and it’s buzzing like a champ with 12v on it.

I’m in a storage place, I want to work on the car and have it set so she’s running like a top. At the same time you need to have a benchmark and enough experience to reference it toward something.

A little knowledge is a deadly thing in my biz, so I’m taking that mantra to this.

I have Wayne’s book and the PDF you have.

Car still works great. Really appreciate the posts.

I swear we have the same car. I’ll do another vid today or tomorrow. Cold here again.

My 86 was build July 85 and has some 85 stuff vs a late 86.

The plated Oil Cap, the same stickers as you on the hot air pipe, and the snap back rear seats vs the Pull centre pins. Things you learn along the way.