Up & down idle 88 Duke when warm

[Donster]

Can somebody provide me with a wiring diagram, as I don't have a shop manual for the 88. 

Anyone?

Or does someone have an 88 SM for sale? 87 SM here in Germany was sold before I had a chance to buy it.

On the ECM connectors I found the following:
Had a steady 12 V on W(hite)10 & 15 (battery and ECM fuse), although scan tool told me only 9.6 V???
Had a good ground on W(hite) 12 & 13 (system ground).
Had no ground on B(lack)12 (sensor ground for TPS & CTS) and on W(hite)14 (sensor ground for MAP & MAT), so I added ground by splicing in two wires to the harness and to the chassis, just for troubleshooting purposes. Peculiar though, I had ground, when measured directly at those aforementioned 4 sensors, so I assumed, I had broken wires somewhere in the harness???
Made no difference in the hunting idle, but feels like the car is running worse now.
Is ground on those two connections only provided when ECM is running (ignition "ON")?

Guess I need not mention that this is driving me insane now!

Thanks for ANY suggestions, especially if I did something wrong!

\D

[Raydar]

On the ECM connectors I found the following:
Had a steady 12 V on W(hite)10 & 15 (battery and ECM fuse), although scan tool told me only 9.6 V???
Had a good ground on W(hite) 12 & 13 (system ground).
Had no ground on B(lack)12 (sensor ground for TPS & CTS) and on W(hite)14 (sensor ground for MAP & MAT), so I added ground by splicing in two wires to the harness and to the chassis, just for troubleshooting purposes. Peculiar though, I had ground, when measured directly at those aforementioned 4 sensors, so I assumed, I had broken wires somewhere in the harness???
Made no difference in the hunting idle, but feels like the car is running worse now.
Is ground on those two connections only provided when ECM is running (ignition "ON")?

Guess I need not mention that this is driving me insane now!

Thanks for ANY suggestions, especially if I did something wrong!

\D

That's quite possibly just a "logic ground" or "logic common". Not necessarily "earth ground" or "chassis ground". If it made other things worse, I would be inclined to undo it.
I've got an 88 manual. Let me see if I can get a workable copy of the diagram.

Edit - you said you had ground at the sensors, so I'm confused, now.

BTW... the pic of your ALDL data is suspect. All the temperatures seemed to be wrong, as well as the DC voltage(s). Makes me wonder if it's really configured (or written) correctly.
I still don't have my car here, or I'd record my values.

[Donster]

That's quite possibly just a "logic ground" or "logic common". Not necessarily "earth ground" or "chassis ground". If it made other things worse, I would be inclined to undo it.
I've got an 88 manual. Let me see if I can get a workable copy of the diagram.

Edit - you said you had ground at the sensors, so I'm confused, now.

Yes, that confused me also, which is why I'm assuming that perhaps there is a broken wire in the harness.
Then again, I might have been measuring at the wrong pins. I'ts like Russian Roulette without the correct shop manual, having to rely on .jpg's downloaded from the web. 

I'll most likely remove the additional grounds I have added and start over again.
BTW: Found an 88 SM on Ebay. Problem is, I ordered it from the US, so it will take a while to get here (appr. 3 weeks!!).

In case me engine harness is totally hosed, do you have an 88 Duke harness left over from any of your engine swaps? 

Thnx Steve,

\D

[Raydar]

My automatic harness went with the first Duke, when I sold it.
My current Duke has a manual trans, so that's not going to do you much good, anyway. Sorry.

With that said, it shouldn't be too long before I have the Fiero back here, so I can make some measurements. Have to clear out a bit of garage space.

[Donster]

Do you happen to have an 88 Duke definition file for TunerPro ($48??)?I'm not sure I got the correct file with all my scanner software.

Thnx,
\D

[Raydar]

I've got one for TunerCat. I can email it to you tonight. Don't think it will work with TunerPro, though. I might be wrong.

[Donster]

I've got one for TunerCat. I can email it to you tonight. Don't think it will work with TunerPro, though. I might be wrong.

Is that the same program as DataCat by C.A.T.S.? I have that.

Oooops......correction............my trial version has expired

[Raydar]

I'll bet if you uninstall it, delete the folders, and then download it again, it'll work. (Might have to delete registry keys, too.)

But yeah... pretty sure it's the same thing.

But that's a programmer. NOT a scan tool.

[Donster]

Went through the reg with regedit, can't find the reference to the app, no dice.It probably references a name that is so abstract and has no similarity to TunerCat, CATS, C.A.T.S. or anything else, it is virtually impossible to find in the registry.I could change the system clock/date back to before I installed it 7 days ago, but other things would stop working, i.e. my MS Outlook with my Exchange server a.s.o.
If I could find a version older than DataCat v 1.1.2.722, that might work, but no luck so far.

But if you send me the def file, I'll give it a try anyways and would appreciate it nevertheless.
Thnx for all your time and replies-
\D

[Raydar]

I'll see what I can find.
It's installed on another computer.

Edit - Sorry. Got sidetracked this evening. Didn't get to dig up anything that I wanted to.

[Donster]

No worries, couldn't do anything after work anyways. And tomorrow is a holiday in Germany, so we'll be taking the company car to do some family QT. 

[Donster]

But that's a programmer. NOT a scan tool.

But it will enable me to at least read data, no?

What do people with an 88 Duke (DIS) use to scan? Obviously, WinALDL won't work. 

[Donster]

I've got an 88 manual. Let me see if I can get a workable copy of the diagram.

No worries Steve, got the diagram for the 88 Duke, thanks anyways.

\D

[Raydar]

But that's a programmer. NOT a scan tool.

But it will enable me to at least read data, no?

What do people with an 88 Duke (DIS) use to scan? Obviously, WinALDL won't work. 

Nope. All it will do is decode and edit EPROMs. There is a separate program used to read and burn them, that is included in the "package".

What you need is an OBD1 scan tool. (NOT just a code reader.) They're kind of uncommon, now. But the ones that are out there are not terribly expensive. 
I've got an AutoXray 6000. Does OBD1 and OBD2. Don't recall if I've ever used it to scan my Duke, but there really isn't any reason that it shouldn't. It scans everything else, and provides sensor readings and etc. (The display says that it goes up to 2005, but I've read much newer cars with no problem.)
Works like WinALDL, only it's self-contained. Has its own display. Doesn't need a laptop.
If you buy an AutoXray, be aware that they are out of business. Nobody is around to support them. You'll have to buy all your cables and stuff off of eBay, if you don't get them with whatever you buy.
Actron is another "consumer" brand of scan tool.
You might find an old GM Tech1 scan tool, but they might need a lot of expensive modules to make them work. (Not sure, on this point.)

Edit - I was poking around and saw a bluetooth device that supports OBD1 and an android phone or computer, including TunerPro. It has a selectable ALDL baud rate. 160 baud or 8192 baud.
It occured to me that you might be using a similar device. The baud rate of the 88 (and 87) Duke must be set to 8192. They're the only Fiero ECMs that use that baud rate.
If the baud rate is wrong, it could cause bizarre readings, such as what I was seeing on your "dashboard" display. ("negative" temperature readings, etc.)

[Donster]

OK, so what I have is a USB to ALDL cable, and a few programs, among others is TunerPro RT with a definition file (supposedly) for the 87-88 Duke.
My cable actually has a selector switch for baud rates. It can do 160 AND 8192 baud.
I also have ALDL_Test, wich lets me select comm ports and baud rate. It checks out.

This is what I bought:
https://www.ebay.de/itm/Diagnose-Corvette-C4-Camaro-Firebird-VAN-FIERO-FIERO-Truck-Caprice-Transport-TPI/254207006495?hash=item3b2feb171f:g:3QIAAOSwsixcjPkl


I am just wondering if the def file for the 88 Duke is correct. A file name can be changed easily. Once I load it into TunerPro, it tells me it is for a 1991 vehicle??
I've downloaded a $48 file from the internet (source can't remeber), but funny thing is, it also tells me it is for a 1991 vehicle, with a 2.2 liter engine.