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T25 2.0l stock carb tuning advise please!!

Posted: 21 Mar 2012, 23:51
by crazytunes1
Hi all

I have studied bentleys guide but i have a few questions about Tuning?

2.0l cu with stock dizzy with vacume davnce and retard pump
standard solex pdsit carb arangement the one with the central ideling system cleaned and rebuilt with new throttle spindles
Gunson gastester pro
snail type syncrometer
Hot engine with auto chokes open
Timing smack on and vacume advance mechanical advance and vacume retard all working correctly
Idle stabalising unit was removed by previous owner

First off i will need to disconect the vacume retard hose from the retard pump on the dizzy do i need to block this pipe off and do i disconnectr the advance pipe to?
(2) i have been informed its a good idea to diconnect the crank case breather hose or it will give stange reading on CO% also diconnect the linkage on the right hand carb.
(3) i need disconnect the central idelling solenoid wire
(4) i need to decrease the rpm via the screws on the throttle plate stop to about 500-700 rpm using a syncrometer to balence the air flow
(5) then set the mixture to about 3-5% co then increase the rpm by about 100 rpm and diconnect the fuel cut off on one carb and note the decrease in rpm and do the same on the other if one is higher then the other adust the mixture screw on the carb that is lower to bring the rpm to match after this step check the co % using 4% as average.
(6) increase the the rpm back to 950rpm via the throttle plate stop and check the air flow is the same on both with the syncrometer.
(7) reconnect the central ideling system and set the rpm to 850-900 by the idel bypass screw then what do i do with the bypass mixture screw????????
also should i then rev the engine to 2500 rpm and check the air flow sync between the carbs and adjust via the throttle plate stop to ballence the pair ??

Sorry about the woffel but i have had the engine tuned by a so called tuning specialist and he had no idea what the hell he was doing he evan asked me where the diagnostic plug was so he could connect his laptop :rofl

after lots of £££ and fuel dills throught the roof and a van that goes like poo throttle flat to the floor to do 55mph i am going to do what i should have done a long time ago and do it myself if i have missed a step or missed some thing out pipe connection wise etc any advise would be much apreciated before i take on the task.

Look foward to any advise

Kind regards
Crazytunes1

Re: T25 2.0l stock carb tuning advise please!!

Posted: 22 Mar 2012, 07:14
by kevtherev
I could say find your nearest rolling road and speak to them.
I could say think about fitting Delorto drla 36 carbs.

but that's the easy way and most expensive, let's see what others offer

Re: T25 2.0l stock carb tuning advise please!!

Posted: 22 Mar 2012, 08:22
by CovKid
This was covered a while back but can't find post unless it was all put in WIKI. Heres the video/s that go with it though:

http://www.youtube.com/watch?v=4qayyc9Z4E0" onclick="window.open(this.href);return false;

Re: T25 2.0l stock carb tuning advise please!!

Posted: 22 Mar 2012, 10:28
by Footprint
From a little while ago:
Footprint wrote:See this: Linky link.

It's lengthy, but very very wortwhile for a real world way of adjusting the carbs without lots of equipment, as you'll read the timing needs to be set in conjunction with setting the carbs - so you will need a strobe.

Note that it's written with a Yank spec Bay as the example vehicle, as such it has some emmissions equipment that your bus probably won't have, but this does not change the procedure in any material way.

Re: T25 2.0l stock carb tuning advise please!!

Posted: 24 Mar 2012, 00:15
by crazytunes1
Hi Guys

Thank you for your replys and info verry helpfull but i am still at a miss do you disconnect the vacume retard pipe and block it off before tuning??

Regards
Crazytunes1

Re: T25 2.0l stock carb tuning advise please!!

Posted: 25 Mar 2012, 22:13
by crazytunes1
Hay guys

Just to give you some feed back i have set to speck and the van goes like "pooh" of a shouvel with smooth aceleration throughout the range however i am having a few tething problems with central ideling system got it a bit rich at mo wich is giving me starting problems when hot way to rich hains maual specs 0.3-0.9 co% on central ideling sytem this sounds a bit lean to me i will give it ago and see if she starts to over heat.