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

[Hotshot]

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

[archstanton]

Sounds great!

[Pedro '84 Coupe]

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

[jons911]

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

[Hotshot]

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

[Hotshot]

Originally Posted by Pedro '84 Coupe

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

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

[73pcar]

Originally Posted by Hotshot

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.

[Pedro '84 Coupe]

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.

[proporsche]

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

ivan

[stlrj]

Originally Posted by proporsche

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

[Hotshot]

Originally Posted by stlrj

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.

[monkeyodeath]

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.

[Hotshot]

Originally Posted by monkeyodeath

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?

[monkeyodeath]

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.

[proporsche]

..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;-))))

[stlrj]

Originally Posted by Hotshot

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....

I come here to learn.

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

[jlex]

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 .

[Quicksilver]

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.)

[Hotshot]

Originally Posted by monkeyodeath

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

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

[Hotshot]

Originally Posted by Quicksilver

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.)

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