I believe it is on the Scions of Lucas (SOL) site. Ah, yes, here it is:
http://www.team.net/sol/tech/su-tune.html
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires
on 6/25/03 9:35 AM, Paul Root at proot@iaces.com wrote:
> I spent a while this morning looking for it in the archives. Not so much
> luck. I'm sure it's there, but without a time frame, it's very difficult.
>
> Any chance that any of our web guys (Paul, Barney, Paul, Skye, others?)
> have this on their sites?
>
> Paul.
>
> Glenn Schnittke wrote:
>> Marc,
>>
>> You wrote:
>>
>>> I'm in need of some advice (how unusual...) to diagnose a problem I'm
>>> having. My '80 MGB with the dual HIF setup I installed had been running
>>> great. Over the last two weeks, it's gotten difficult to start when cold,
>>> and runs rough, spitting and backfiring until it warms up really
>>> throughly.
>>> Then it runs mostly ok.
>>
>>
>> I'll not claim to be an expert on HIF's. It's been a good ten years
>> since the Maroon went under. But I found them to be very reliable when
>> in good condition, and since my cars have always been daily drivers, I
>> did like NOT having to retune for winter or summer.
>>
>> That said, has the ambient temperature just started to change in B'more?
>>
>>> I checked plugs, cleaned & regapped, swapped out cap and rotor with new.
>>> After work today, I'll recheck the timing as well.
>>
>>
>> Always a good place to start. As has been said - 90% of all SU problems
>> are electrical.
>>
>>> I made sure that all manifold and carb mounting nuts were tight, and
>>> checked
>>> for leaks with carb cleaner. This is a fairly new installation that
>>> had been
>>> running really well.
>>
>>
>> You didn't say how long you had the HIF setup on the car, but if they
>> ran fine last summer, and you didn't really do anything to them until
>> crap-out other than normal maintenance then that draws one conclusion.
>> If you set them up over the winter and (etc) that draws another.
>>
>>> I was thinking I should just go through the whole set-up procedure
>>> again. Is
>>> that a normal occurance to have to do that?
>>
>>
>> Not really but I can't tell you how many times I've done it anyway. Due
>> to the nature of the cars, I would advise checking for vacuum leaks
>> first. Check your throttle plates for poppet valves. If you have them
>> they will tend to go bad or just not work and make your life miserable
>> trying to find the problem. If you have them, my own advice would be to
>> make them go away. I just did it to a very fresh complete rebuild on a
>> set of HS4's and NOW they work beautifully. (Drilled them out, filled
>> the hole with Marine-Tex {I think it's better than JB Weld} and filed it
>> down almost flat. Lovely).
>>
>>> Lacking experience, I'm not always sure that I'm doing these procedures
>>> correctly. Seems it's more of an art than a science...
>>
>>
>> Couldn't have put it better.
>>
>> Go to the archives. Pick up Roger Garnett's post on tuning SU carbs. He
>> wrote it for HS's but they are basically valid for HIF's, too. When I
>> first got into these cars I got the Bentley Manual, I got the Haynes
>> Manual, I got the Haynes SU Manual. Then I found Roger's file and
>> finally understood them. I still use it as a refresher course every fall
>> and spring. Follow it to the letter (including the ale). Then you have
>> done the complete procedure. You didn't say you'd adjusted the valves.
>>
>>> Also, I'm considering the purchase of a Gunson Colortune. Are these
>>> useful,
>>> especially for a novice?
>>
>>
>> I use one on occasion. Rather than using it to actually find the right
>> tune I use it to balance the front and rear carbs. I use it in the same
>> context as the Uni-syn. Once I find the balance, I get rid of it and
>> listen. Drive. Check plugs. Listen. Drive. Check plugs. Listen. Drive.
>> Check plugs. Ad nauseum. I think it's more fun that way.
>>
>> Glenn
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