Outer Limits 4x4 Board

For those of you who are familiar with the 1.3l stock carbie, at the back left there is a diaphragm which when vacuum is applied to it it opens the secondary throttle valve. Now at the moment I am running on just the one barrel and the cars feeling sluggish. The diaphragm does work but the hose going to it has no vacuum, it's just a dead hose. I'd be really grateful if someone could quickly check where the other end of the hose goes to if they got some time. I'm pretty sure my hoses are mixed up. Thanks a lot.

I didn't think that hose had vacuum till the manifold had pressure?

Have u tried taking the hose off and going for a fang.

cheers

too hard to get that vaccuum without real life driving.
On mine, the mechanism that is actuated by the diaphragm seized up, wd40 fixed it.

put a hose on it, suck and blow, see what moves.

Also, if you have done any tire clearing work on the drivers footwell, your throttle may not be fully opening...I had to space my pedal out to get my 2ndary to work again.

christover

this may help, tho mine has most hoses blocked off for various reasons

these pix were taken for another issue, but you can just see the actuator pipe, it goes round the back of it to a really hard to reach point.

It's a bit hard to see from those pics. The diaphragm is fine, when I suck on it it retracts the rod opening the secondary throttle. It should be opening even slightly when I rev it, but doesn't budge. Fact is there is no vacuum coming from the hose, even under load. If I suck on the hose I can actually see the throttle plate move, and I tried experimenting by hooking up the vacuum advance hose to the diaphragm, and it makes it work. However it hesitates big time on acceleration, and when I take took out the spark plugs after this little trick they went from black (rich) to white (lean). So maybe I have to raise the float? This is so confusing. By the way is there any way to change your mixture without taking the top off the carbie ad adjusting the float?

Cars just sluggish and I'm trying to get to the bottom of it.

I think the secondary is not supposed to open till hi revs/hi load/and nearly full accelerator pedal. Chances are it is working properly. Also, connecting it to the vacc advance showed you it does work. Having it open too early would make it run bad. You would have to be driving it on road with head under bonnet to find any vacc on the 2ndary pipe.
I'd get somebody to hold acc pedal flat to the floor, then pull on the acc lever at carb and see if there is still more travel left.
Mixture is preset on stock carbs, though carb gurus probably know how to change stuff, but if carb is clean and has good seals and gaskets, they are usually right. Float level usually only affects performance on steep hills and angles.
Carbs on 1.3's need a lot of pulling apart to get to most stuff.

christover1 wrote: Float level usually only affects performance on steep hills and angles.
Carbs on 1.3's need a lot of pulling apart to get to most stuff.

Not on the zook but the float level was all messed up on the hilux resulting in the fuel bowl completely filling making the carby flood.

Pretty easy to set the float level. On the hilux you only need to take the top section apart leaving most of the carby on the car.

If you do pull the carby off make sure you mark/label all of the vac/fuel lines before removal. This way they all go back on in the right place first time.

If you're not sure how to do it, pull the carby off (after marking the lines) and get your carby rebuilt. Should only cost about $140-160.

Id probabily guess that the vac port is clogged with carbon or some other crap. Also with the std zuk carb, the secondary should only open under heavy, near wide open throttle. Sinse the secondary is opened by high vacume and near full throttle via the linkage configuration.

It's running shocking. Christover you may be right that the secondary may only open at high rpm under high load, but I revved it pretty hard and high and nothing showed on the vacuum gauge.

87suzi wrote:It's running shocking. Christover you may be right that the secondary may only open at high rpm under high load, but I revved it pretty hard and high and nothing showed on the vacuum gauge.

I'm pretty sure its the external parts that control when secondary opens. So if they all seem to be working, then vac must be blocked, which is not impossible, but is unusual. Try putting a hose on the carby part of the vac and blow through it, see if it is blocked, or maybe this would unblock it?

I assume you are certain nothing else is the problem.
Carbies can be a pain in the **** when dirty fuel gets in, or when seals etc get old.
I have had no issues with my carb since I changed fuel tanks, put a carby kit through it and fitted an efi type fuel filter.

PS.
I have a spaRE CARBY IF YOU WANT TO LEND IT, AND SEE IF THAT FIXES THE ISSUE.

BLOODY CAPS LOCK

christover

thanks for all the help. Tomorow's saturday and I'm gonna get down and dirty with it, I'm not giving up until I fix the problem even if I don't go to sleep tomorow night.

I know this is an old story, but I've made some progress. I'm now running a completely different hose to the vacuum diaphragm and the secondary seems to open. Car has a lot more pickup too. Anyone know what that little long device that screws into the intake manifold is? It's got to little nipples where hoses are supposed to go. I've go it running from one of those nipples.

Heh heh, nipple

photos?

good work at least its going good again.