4g54 Weber 38/38 jetting

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shuggy
Posts: 2269
Joined: Tue Mar 24, 2009 12:35 am
Location: Perth, WA

4g54 Weber 38/38 jetting

Post by shuggy »

Hi team.

Need some advice. I've been paying with Jets for my 2.6 with Weber 38 synchronous in my galant Wagon as my fuel consumption is ridiculous. Performance was amazing with the last setup with huge torque but I've dropped a main Jet size and now I have a really bad problem off the mark.

I had :
Main 165
Air 185
Idle 50

Changed main to 145 and now really bad. I just want Ok performance and less fuel expenditure. Question, is it possible for the accelerator pump to over fuel the carbs? I feel this could be half the problem.
scully
Posts: 7
Joined: Fri Nov 11, 2011 3:21 pm

Re: 4g54 Weber 38/38 jetting

Post by scully »

50 idle jets will be too lean on a 2.6. I use 50 idles on a 4g32 with a 38/38. The key to getting good performance AND economy out of a weber is to set up the low speed circuit correctly. The idle jets do more than control the idle on a weber, they control basically all your low speed running. Get it wrong and you will get flat spots and poor economy.Get it right and you will be rewarded. My sons 4g32 gets 8lts/100 on a cruise, and an massive increase in power. Drive it hard and it drinks a bit though.... Check out http://www.piercemanifolds.com/category_s/313.htm, it goes though basic weber tuning. They also have a good dvd for sale the really explains weber tuning well. Worth buying
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davetrees
Posts: 1044
Joined: Sun Mar 22, 2009 5:02 am
Location: Sth Gippsland, Victoria

Re: 4g54 Weber 38/38 jetting

Post by davetrees »

shuggy wrote: I just want Ok performance and less fuel expenditure.
Put a 32/36 DFV on it then (or a 34ADM ?) ... something progressive, anyway. The 38DGAS is designed as a performance carb, not for economical cruising !
shuggy
Posts: 2269
Joined: Tue Mar 24, 2009 12:35 am
Location: Perth, WA

Re: 4g54 Weber 38/38 jetting

Post by shuggy »

Hmm.

I want to keep the 38. I understand that around town will be huge fuel but I am getting 19L per 100 km at the moment on cruise running huge advance. And I mean huge Like 25 static with no pinging. I wound that back when I put smaller main in to 10ish static to stop pinging.

I have ordered 20 or so Jets to play around with. Se how I go. Someone said increase air Jets to 205 so might try that too
Jek
Posts: 3
Joined: Tue Jun 12, 2018 7:48 pm

Re: 4g54 Weber 38/38 jetting

Post by Jek »

You guys got any baseline ideas on jetting a 38/38 for a 4g52 2.0l?
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