Author Topic: Idle problem 1981 GTV 2000  (Read 6595 times)

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fazersix

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Re: Idle problem 1981 GTV 2000
« Reply #30 on: October 18, 2020, 11:06:36 AM »
Carbs back on and first start up it ran and idled, ran like it had a fouled plug! Cleaned no 2 no change. Checked the fuel level it is at 27mm in the middle - I adjusted this on the bench using an old squeeze sauce bottle, gently squeezing to simulate 3lbs pressure which worked well!
Took some time to read and think things over then realised I had moved the carb sync screw during rebuild. Adjusted that and it is running pretty nicely, idling around 900rpm.
Now to tune the mixture and proper carb sync.

Update:
Had time to do the tuning, set mixture, using two gauge vacuum meters balance both ports in each carb and then then checked the carb to carb balance. Idling nicely around 900rpm and returning to idle after revving.
 
Test run, now revving sweetly and finally hits 6000 rpm.
Thanks to all who helped me on this post.
« Last Edit: October 18, 2020, 04:24:02 PM by fazersix »

carlo rossi

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Re: Idle problem 1981 GTV 2000
« Reply #31 on: October 19, 2020, 04:23:37 PM »
try and get hold off the 34mm chokes with 155 mains or 152mains with 32mm
current cars
red 83 gtv 2.0


previous cars
Red 76 1.2/1.5 alfasud ti
white 79 alfetta 2000
alfetta 74 1.8
escort Lotus twin cam
bikes
ducati 900 ss 1979
moto morini 3 1/2 sport 1975/6
Moto morini 3 1/2 valentini speciale 77 oh and a deltek rockhopper

fazersix

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Re: Idle problem 1981 GTV 2000
« Reply #32 on: October 19, 2020, 05:58:05 PM »
Hi Carlo,
The 34mm chokes (because I am running 155 jets with 32mm chokes ATM) are around $100 from Eurocarb and could be a pain to fit if stuck. If I am lucky I can remove them whilst the carbs are on the car!
The 152 jets are around $50 and an easy change.
Will the 34 mm chokes give a noticeable performance increase over the 152 jets?

Cheers

carlo rossi

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Re: Idle problem 1981 GTV 2000
« Reply #33 on: October 23, 2020, 10:15:33 AM »
really it only picks up the top end from 5000rpm to 5500rpm
particularly if 155 jets  are too big
current cars
red 83 gtv 2.0


previous cars
Red 76 1.2/1.5 alfasud ti
white 79 alfetta 2000
alfetta 74 1.8
escort Lotus twin cam
bikes
ducati 900 ss 1979
moto morini 3 1/2 sport 1975/6
Moto morini 3 1/2 valentini speciale 77 oh and a deltek rockhopper

fazersix

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Re: Idle problem 1981 GTV 2000
« Reply #34 on: October 30, 2020, 07:20:14 AM »
Hi since I don't rev past 5000 very often I have kept the 32mm chokes and changed the mains jets to 150 and the idles to 58 which appears to be a stock setup for a euro spec with 10548 cams. Re-tuned the carbs and it is running very nicely - smooth idle around 900 and pulls nicely through the rev range. Now on to the next project to drop the front by25-30 mm to make the car sit nice and flat - more reading of posts on the torsion vernier adjustment!

Colin Edwards

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Re: Idle problem 1981 GTV 2000
« Reply #35 on: October 30, 2020, 11:10:29 AM »
Good move to hang in there with the 32's.  Although the 34mm diameter is 6.25% greater than the 32mm, the "theoretical" choke area of the 34mm is 13% greater!  No point having "theoretically" 13% more flow potential if your not going to use it!  Besides..............there is no substitute for gas velocity!
Present
2020 Giulietta Veloce
2018 Abarth 124 Spider
1987 75 3.0

Past
2015 Giulietta QV
2009 159 3.2 Ti Q4
2012 Giulietta TCT Veloce
2006 147 Ti 2 door Selespeed
1979 Alfasud Ti 1.5

carlo rossi

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Re: Idle problem 1981 GTV 2000
« Reply #36 on: November 03, 2020, 09:56:34 AM »
agreed the jetting should be good with 150 with euro and 32mm chokes
148 was stock
and it uses alot less fuel than the old cams
so much for pollution spec cams
but if you ever get the chance the 34mm chokes are wonderful
but you have change idles mains and such
hoiws the new emulsions tubes feel the 77772.8 should be perfect
current cars
red 83 gtv 2.0


previous cars
Red 76 1.2/1.5 alfasud ti
white 79 alfetta 2000
alfetta 74 1.8
escort Lotus twin cam
bikes
ducati 900 ss 1979
moto morini 3 1/2 sport 1975/6
Moto morini 3 1/2 valentini speciale 77 oh and a deltek rockhopper

Beatle

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Re: Idle problem 1981 GTV 2000
« Reply #37 on: December 06, 2020, 02:35:42 PM »
Now on to the next project to drop the front by 25-30 mm to make the car sit nice and flat - more reading of posts on the torsion vernier adjustment!

From a VERY distant memory, to drop an early, long T-bar Alfetta by a  whole inch you can go one spline on the front only.  No need to do the vernier maths to rtate the rear splines.   Regardless, it's simple enough to give it a go and return it if you don't like the results (like a busted sump, or flattened 2-into-1 pipe, or like me, tore the headers off at the head.......).

If it were me, I'd raise the rear end.....
Paul B
QLD

Past:
'79 GTV - Loyal 1st love
'76 GT - Track entry
'89 75TS - Saved
'76 Alfetta - Sacrificed
'83 GTV6 - NT bullet
'67 Duetto - Fun
'66 Super - Endearing
'92 164 - Stunning
'85 90 - Odd
'04 GT 3.2 Rosso/Tan - Glorious
'02 156 V6 Auto Rosso/Tan - Useful daily