Up & down idle 88 Duke when warm

[Donster]

I've been looking for a scan tool for the 87-88 L4, but they are all in the $300+ range.   
For the mean time a paper clip (I actuall have the Code Reader key from the NIFE Club) will just have to do.

[GTRS Fiero]

The reader will not reset the code.

[Donster]

The reader will not reset the code.

I know. To do that, I always disconnect the battery.


\D

[GTRS Fiero]

That may not be enough on an '88.  The ECU is different.

[Donster]

From what I have read on various boards, it should suffice.
I haven't found it yet, but supposedly, there is even a connector to disconnect only the ECM from power, eliminating the need to reprogramm all your radio stations. 

[Fierofool]

That's correct, Don.  The ECU disconnect/power supply comes off the C500.  It's a round cylinder about 3 inches long.  It's a weatherpak connector on a red or orange wire.  The connector is the same style as was used on the early model headlight motors.  It should be at approximately the lower corner of the positive end of the battery.  Disconnecting that will wipe out all stored codes in the ECU. 

[GTRS Fiero]

There is an image of that connector in the December newsletter.  My understanding is that removing that power works to clear codes for the stock V6 ECU, and for the '84-'86 L4 ECU.  I'm told it does not work on the 7730 or the DIS '88 ECU.

[Donster]

Fuel vapor canister filter is good, but replaced anyways, checked for correct gas cap (I read that the Fiero should have a non-vented), swapped the two lines from the canister to TB (you never know if the PO might have had a brain fart), then I just replaced both vacuum lines with new ones.
Still hunting idle when warm.
According to tracking no. the refurbished ECM is between the US and Germany now, so it shouldn't be long.
If that doesn't fix it, I'm getting rid of the Fiero and getting an old VW Carman Ghia. 

[GTRS Fiero]

These fun things are all part of Fiero ownership.

[GTRS Fiero]

Did the ECU arrive yet?

[Donster]

No, still in transit

[GTRS Fiero]

I couldn't wait that long.  I'd be old and grey by the time things arrived.

[Donster]

I AM old and grey! 

[GTRS Fiero]

See what waiting for parts does?

[Donster]

OK, parts arrived today.
Installed new (refurbished) ECM, new MAP.............. still hunting idle!!! 

Here my question; can a faulty oil pressure switch cause idle problems? I know the fuel pump relies on information from the OPS.....and I also know that I accidentally shorted the OPS a while back, trying to connect it correctly again (Raydar told me I probably blew the fuel pump fuse, which was dead-on!), because the PO hacked around on the cables (only 1 cable connected to the OPS). I'm suspecting that something has been wrong with the OPS from the beginning. The PO also installed an 87 OPS instead of an 88 OPS, which I have, plus the 88 connector.
So while watching my instruments, I notice the fuel pressure takes a dip, then right after that, my idle takes a dip. It almost sounds like not enough fuel when the idle dips.
Does what I am explaining here make sense? Could it be related? If the moon is in the seventh house and the wind is blowing just right?

Frustrated in Germany and still old and grey...........Don