1988 Beretta GT Rough idle when "cold"

[zcylex]

UPDATE: finally got the "new" ECM up and running and is working fine and all my DTC codes are gone, i still have to get the IAT and a few more tweaks to make the air conditioning work again but thats another story. will be making a new thread later for progress thanks everyone.

[ifixalot]

I found this thread while looking for an answer to my 88's code 23.
I bought a spare MAF and put it on. Every now and then I get code 23.
Now I see, I have a sticker that says my car has been updated to speed sensor.
I still have the MAF on it. I have no separate IAT so I assume maybe the replacement MAF temp sensor is bad.
I put back the old MAF and we'll see what happens.
Maybe later, I'll put a piece of pvc pipe and a separate IAT in there, I want that 5 extra horses!

[Rettax3]

I found this thread while looking for an answer to my 88's code 23.
I bought a spare MAF and put it on. Every now and then I get code 23.
Now I see, I have a sticker that says my car has been updated to speed sensor.
I still have the MAF on it. I have no separate IAT so I assume maybe the replacement MAF temp sensor is bad.
I put back the old MAF and we'll see what happens.
Maybe later, I'll put a piece of pvc pipe and a separate IAT in there, I want that 5 extra horses!

ABS looks better (black) and isn't as brittle as PVC... Just saying.

[ifixalot]

Good idea but my Home Depot doesn't seem to have 3" abs pipe.
I'll have to look around. I didn't even see any short lengths on evil bay.

[Rettax3]

I think I used 2" on my Turbo 'Retta's original 3.1, and positive that is what I am using on the Turbo Z-24... That is nominal I.D., ABS is ~ 3/16" wall, so about 2.375 inch O.D. -plenty of pipe for a 2.8, 3.1, or a turbo-charged 2.4/3.1 engine too, and it works fine under pressure. If you think it is restrictive, look straight into the throttle-body, with the butterfly wide open...

[ifixalot]

The OD of the MAF is 3.1" OD one direction and 3.25" OD, at 90 degrees. 2 inch seems small to me.
I'll figure it out. If I use PVC, I can always paint it.

[Rettax3]

IIRC the '88 MAFs had a very tight neck through the middle, like a venturi. Personally, I just don't like PCV because it gets so brittle when cold, ABS has no compromises vs PVC and is just stronger and less brittle. But, if the size available doesn't look right to you, PVC is probably fine for your application, you don't live in Alaska to be that concerned over the cold and you aren't running boost -I've even seen some schedules of PVC rated for +/-400 PSI. Looking forward to your upgrade, particularly the IAT swap-out.