Wow thanks for the long response!!! I will try to answer your
questions....
1) Yes, it sounds like a good idea to vent into the Longflow if I can
get it to work.
They provide a way of doing that.
2) I have taken carb cleaner and sprayed all hoses and fittings looking
for leaks.
I have not found any.
3) I have a flexible rubber hose going from the valve cover to the carb.
No PCV valve to the carb, no Y with a PCV valve that goes to the
charcoal canister.
4) When I test the car with out a filter I remove everything. No
backing plate, no foam.
I did however try inserting the screws that hold the air filter back
plate on. This was just
Increase there was some port in there that I could not see.
5) I have an oxygen sensor and a meter to read it, however, I have not
hooked it up.
I need to drill a hole and weld a nut on the headers. The threads on
the oxygen sensor
are strange. 15mm??? metric???
6) I may have access to color tune. Our club was thinking of buying it.
I wonder if
they are on to that? .... Mmmmm. I will give them a call.
>----------
>From: Charlie Brown[SMTP:cb1500@erols.com]
>Sent: Monday, July 28, 1997 11:42 PM
>To: Childs, David
>Cc: triumphs@autox.team.net
>Subject: Re: ZS Problems
>
>David,
>
>When I was running a single ZS, I vented the charcoal cannister
>through a hole in the backing plate of the air filter. The object of the
>charcoal cannister is to store the fumes from the fuel tank then gently
>draw them off while the car is running. The vacuum created within the
>filter housing is generally enough for that purpose. I think the Longflow
>comes with holes drilled and plastic 1/2" fittings. Mine did 2 years ago.
>
>What else, if anything, have you got attached to the carb's vacuum port?
>Are you creating a large air leak through that port. How have you routed
>the crankcase ventilation?
>
>When you say if you remove the filter, the car will run. Does that mean
>just the foam, or the backing plate also. Is the backing plate covering
>the air compensation port for the carb piston chamber?
>
>I've got one of those red Purolator fuel pumps. They are supposed to
>produce 4-7 psi. If you're only getting 2.5 psi, something's clogged or
>not working properly. That will definately cause the highway driving
>problem you're having. The pump can be disassembled for inspection by
>unscrewing the shorter of the two 7/8" end fittings. Do not, repeat, do
>not try to remove the housing cover. I destroyed a perfectly good pump
>finding that out. As the fitting comes off, watch how the parts come out
>for proper reassembly. There may be a small piece of gas tank crude in
>there, keeping the pump from producing proper pressure. If there's no
>dirt inside, perhaps it's time for replacement. Stick with the red pump
>and a pressure regulator dialed to about 3 psi.
>
>Unfortunately, later ZS carbs are best tuned with a CO meter. I've got a
>unit that's similar to the Gunston (sp?) that's carried by Moss, JC
>Whitney, etc. Some folks have good luck with a Color Tune.
>
>Your best be at this point is to compare the backing plates of the OEM
>and the Longflow, looking for any differences that may be causing air
>blockage. If necessary use the OEM filter to get the car working
>properly, then change over once you know the car is running right. I
>think I'd be inclined to cap off the vacuum port during the initial
>mixture setting to make sure the car is running only on the air/fuel
>coming through the venturi. That should also make any adjustments
>more noticable. Then, hook it up to the crankcase ventilation, using the
>proper restriction fitting between the 1/2" hose and carb tube.
>
>Good luck,
>Charlie B.
>Spitfire Pilot
>>
>> Has anyone used the Longflow air filter on a Spit with a ZS carb?
>> Has anyone successfully removed the charcoal canisters?
>>
>> Here is what I have found.
>> If I remove the charcoal canister and plug the hole on the carb the car
>> will
>> not start. If the car is running and the hole is plugged the car will
>> stall.
>> Note when the car runs all other holes on the canister are plugged.
>>
>> If I remove the air filter (big black can) the car will not run smoothly
>> over
>> 4000 RPMs.
>>
>> I have tried tuning the car with the air filter off. Runs fine up to
>> 5000.
>> It seems the problem is when I get it on the road and put the car under
>> a load
>> that I lose power and does not run correctly. However, as soon as I put
>> the old air filter
>> on it it works. It should also be noted that when I tested it with no
>> air filter I used
>> the air filter screws.
>>
>> I have a fuel pressure gauge in line along with a regulator. I have
>> installed a electronic
>> fuel pump. The electric fuel pump is a red labeled Prolator (SP?). As
>> I recall this pump
>> could deliver more fuel than the blue label pump. My fuel pressure
>> gauge will not exceed
>> 2.5 PSI. To get 2.5 PSI I need to set the regulator to 3.5 or better.
>> Why? Note my old
>> mechanical fuel pump would deliver 2 to 2.5 PSI.
>>
>> Here is my tuning procedure. I adjust the A/F ratio with the special ZS
>> tool until
>> I get my idle to a maximum. Is there some other way? I make changes in
>> ¼ turns or less.
>> I do not see much of a change between ¼ turn too rich and ¼ turn too
>> lean. Is this
>> normal?
>>
>> I have new clear glass fuel filters that do not seem to be collecting
>> any crud. Could
>> I have a partly blocked line?
>>
>> I hope that someone out there can help me with this one! I don't know
>> what else
>> to try.
>>
>> Thanks
>> Dave C
>>
>> 79 Spit (stupid ZS carb)
>> 75 Spit (parts)
>
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