[oz17ub]

driving home today and i had no power. diagnosed the problem as the secondaries solenoid not switching. can anybody tell me where it swittches from?

[Gwagensteve]

There's a solenoid that switches the secondaries? I was pretty sure they were vacuum?

Steve.

[oz17ub]

they r but theres a small solenoid that control when it turns.
its maroon on the drivers side just below the air hat.

[TZAR]

SO you looked at hem when you were stationary and they wernt operating????

You do realise that they only open when the engine gets under load. May I suggest getting a friend to watch them and load the engine up by putting it in first gear pushing as hard as you can on the brakes and then bring the clutch up slowly getting the engine to bog down and then see if they do anyting.

[Gwagensteve]

I've just checked the FSM.

The secondaries are 100% vacuum actuated once the throttle is open "nearly 51˚and the vacuum (in 'A' is as shown in the below figure exceeds -40mmAq"

There is NO solenoid or other electrical item associated with the secondaries. Honestly.

The maroon solenoid on the driver's side under the air hat is the idle up solenoid. It is referred to as "brown" in the FSM but I know the one you mean. Voltage is applied to this solenoid if the rear defogger, headlights, or heater blower is turned on, and it bumps the idle up.

If your secondaries aren't operating, odds are there's a vacuum leak to the actuator which is on the rear of the carby. Are they physically opening, or is it that the secondary jet is blocked?

Steve.

*phew* that's more carby talk than I've done for years. t head hurts.

[Daves4wd]

Easy fix you could try make it a mechanical secondaries as they do on Nikki carbs so it opens when the throtel is at a certain point it works good but may create a flat spot for when they open I haven't mucked around with the mikuni carb at all worth a shot

[Gwagensteve]

Would you recommend mech secondaries on a street driven car? Surely they are more of a race/strip part? They'd be hell for economy, no?

Steve.

[Daves4wd]

Gwagensteve wrote:

Would you recommend mech secondaries on a street driven car? Surely they are more of a race/strip part? They'd be hell for economy, no?

Steve.

I would yes it's more control for when they open takes some getttig used to but well worth it... Just a suggestion hahah all it should need is a screw to to activate the secondary shaft pretty simple....
But in saying of your fuel bill matters go get it rebuilt costs a bit but worth it in the end

[SuziBlu]

My 32/36 is mechanical secondary, on the vitara it averages just over 8 liters per hundred kays on the open road at a pretty steady 100kph, around the streets, bout 9.

I just fueled up, a tad shy of 300k and 25l to fill.

8.3 liters per hundred kay. Totally stock except for carb and coil.

Not sure what the syncro 38s are getting, done a couple of runs, shocking, been tuning by ear n bum, lots more power, not much stumble left, prob about 12 liters per hundred when driven at 100, WOT is a different story. Stock gears, 33s, few goodies to help it along.

[royce]

Daves4wd wrote:

Gwagensteve wrote:

Would you recommend mech secondaries on a street driven car? Surely they are more of a race/strip part? They'd be hell for economy, no?

Steve.

I would yes it's more control for when they open takes some getttig used to but well worth it... Just a suggestion hahah all it should need is a screw to to activate the secondary shaft pretty simple....
But in saying of your fuel bill matters go get it rebuilt costs a bit but worth it in the end

this is really bad, all of a sudden the carb can flow a lot more air than the engine can deal with, airspeed in the venturies drops and it cant meter the fuel properly and gets all sorts of mixture dramas, so you get to go slower.

if you think the secondaries aren't opening, pull the vacuum hose off and plug the source and go for a drive, then you'll know all about slow

[oz17ub]

ok dont i feel a little retarded...

my main issue is im now using quite a substantial amount of fuel. n this has only been a recent development. can anybody give me somewhere to start as to how to try n rectify or find the source of problem?

[droverdave]

hmmm id start at the basics.

clean clean clean to start with.

get some of that carby cleaner, take the air filter pipe off, start the engine, and spray carby cleaner into the carby with engine on. Get it shiny shiny clean! you will need to get on the throttle and keep the engine going as the carby cleaner tends to kill the engine a bit.

you can also turn engine off, spray carby cleaner everywhere in the carb, then start the engine (it will be hard to start) and carefully put your hand over the carby inlet, VERY carefully. this creates huge vaccuum in the carby and will pull any dirty/grit out of the carby into the engine. once again be careful, as it will be a huge sucking force on your hand. you dont have to completely seal it, just enough to get some more vacuum in the carby/inlet.

Once you done that, check to make sure any of the millions of vac pips arent loose or cracked, they go hard over time, and dont seal as well on where they are supposed to go. i just pulled the inlet manifold off my g13a, and pretty much all the vac pipes are rock hard i cant imagine they are sealing very well. im going to buy a few metres of vac line and just replace them all.

And hopefully in all of this you find a problem.

[Gwagensteve]

Sound advice.

Steve.

[tanshi]

replace them all one at a time.
really easy to loose where they go other wise.!!!!

[droverdave]

Also i just had a random throught.

does your carby have auto choke? do these stick on?

if its stuck on that would use a fair chunk of petrol and go very slow doing it.

[neofitou]

I think Steve125's sierra has some solenoid on the secondary, it was faulty and he couldnt get a replacement. So maybe some carbies do have them?

[Daves4wd]

Vacuum seconderys are activated by a diaphragm?? (Haven't got the book on me to have a look) if I am correct and if it is it could have a small hole in it

[oz17ub]

thanks for all the advice fella's. its on the market to be sold so its booked in for a complete carby overhaul and tune. not gonna sell a car that has had a quick fix done,especially with a brand new motor.