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Re: 1988 Beretta GT Rough idle when "cold"

Posted: Sat Oct 05, 2013 10:11 pm
by 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.

Re: 1988 Beretta GT Rough idle when "cold"

Posted: Thu Feb 20, 2020 2:30 pm
by 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!

Re: 1988 Beretta GT Rough idle when "cold"

Posted: Fri Feb 21, 2020 1:29 am
by Rettax3
ifixalot wrote: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. :wink:

Re: 1988 Beretta GT Rough idle when "cold"

Posted: Sat Feb 22, 2020 10:16 am
by 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.

Re: 1988 Beretta GT Rough idle when "cold"

Posted: Sat Feb 22, 2020 4:55 pm
by 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... :)

Re: 1988 Beretta GT Rough idle when "cold"

Posted: Sat Feb 22, 2020 6:12 pm
by 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.

Re: 1988 Beretta GT Rough idle when "cold"

Posted: Sun Feb 23, 2020 2:16 am
by 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.