HiAce auto choke problem (Petrol NZ '95 2RZ engine carb not EFI)

[F5 Dave]

Well here I am in a bike forum asking for 4 wheeler help. But its ok, it is vital for hauling Roadrace, Dirtbikes & the occasional recalcitrant roadbike around.


You'd be surprised at the lack of info on NZ's favourite van. Some of the forums are hardly populated. I'm hoping there will be an actual mechanicy type chap with expertise in these old things. I'd risk taking it to the local garage, but I'm not sure I'd get anything more than experiments & hours clocked up. I need someone with some real life time on these things.

Ok here's my issue. I know sod all about how these car type things work, (I'm a bike guy & handy enough with a spanner), instead of an electronic control, or a good old cable they operated on a system of vacuums from various bits that connected to the carb to adjust the mixture or the idle speed it seems. Not what I'm used to.

Additionally there is an idle up on the power steering. Turn the wheel & the idle goes up. Except mine doesn't. I noticed there was a tube missing from the power steering. Compared to a mates' its just a vent with a tiny filter. Other tubes go to carb & operate the idle increase diaphragm thingy.

The main symptom is the idle speed was racing a bit when cold. You'd turn up at an intersection & it would be revving (say 1500 instead of 600rpm). Eventually when it got hot this usually goes back to normal, but its like its sticky.

As its got colder it can got the other way & stick off & it would be like driving with no choke. So now Ive got two symptoms depending on the roll of the dice.

Can't help but wonder about the P.steering issue or if its a red herring.

I've sprayed some WD40 on the linkages & stuff & sometimes you can see them move as I've sat & watched it get hot. Problem is it seems to behave whenever it thinks you're looking.

There seems to be two of these diaphragm thingys, one at either end, not sure what does what. Vacuum hoses for Africa. And this is an NZ new, no fancy emissions or Aircon options jobbie.

Any idea what gives trouble? Finding parts for these is surprisingly difficult for the Petrol engines, but if I knew what I'd want to replace or repair I'd be better armed.

[unstuck]

Does it have a bi metalic spring in a housing around the carb somewhere?

[FROSTY:Me]

dave this is likely to be little help but my old van did the same thing. In the end the guys just disconnected the auto choke and fitted a manual friction choke for me that fixed it once and for all

[F5 Dave]

That yellow thing in the RH corner of the picture is the dip stick. Ask me about how to measure squish, compression ratio & suitable head shapes in racing 2 strokes & you might get a reasonably informed answer.

[F5 Dave]

dave this is likely to be little help but my old van did the same thing. In the end the guys just disconnected the auto choke and fitted a manual friction choke for me that fixed it once and for all

I actually considered that. But which one pulls what?

[unstuck]

Find the spindle that the choke flap is sitting in, then make up a wee lever/ arm to go on the spindle. then just run a manual cable in.

[FROSTY:Me]

Dave the guy to talk to if he's still around is Motu. He was the genius who kept Lil toot alive.He knows a "fair bit" about those old carb setups.

[Akzle]

shoulda bought a mitsi.

May god help you bru'a

[bogan]

Its not one of those wax choke things is it? My L300 had one of those and it idled like a bag of cats thrown in a tumble dryer that was tumbling down some stairs; which is to say, not very well at all. Basically they just have a life expectancy of not quite as much as the engine, so manual choke conversion is the go there.

[scissorhands]

going to manual choke will save heaps in fuel costs too
raise resell value prolly

otherwise a [old boy at] toyota wrecker near you prolly has the good oil

[ducatilover]

It's a vac air bypass if it's the flavour carb I'm thinking of and should have a temp controlled choke on the primary side? Looks like that black POS in the top of the pic in the middle
If it is, clean the connections, remove it and clean the spring inside it, clean the choke plate and what not.
For the vac diaphragms the only thing that you can really do to them is spray some of that silicone shit in to them in the hope that it'll free it up, don't want to risk anything damaging the diaphragm (otherwise you'll have babies, that's what sex ed taught me)

It probably has a vac operated enrichment pump, separate to the accelerator pump, probably at the rear left of the carb


My real advice:
Cunts of things, throw it away and put a Weber on it.

[unstuck]

My real advice:
Cunts of things, throw it away and put a Weber on it.

Ya bogan. Good advice though. But if it is only the choke playing up it would be cheaper and simpler to put a choke cable in. Check to make sure all those vacum hoses are on too.

[F5 Dave]

Silicone shit huh? Oh well might have to give it a try if it ever gets habitable outside for a'uman again. Might like to get some power back on here too. Cheers

[Ocean1]

My real advice:
Cunts of things, throw it away and put a Weber on it.

Had a 2L 4wd lite ace with a nest of vacuum tube snakes that looked pretty much like Dave's pic. I spent a couple of weekends on it trying to sort vacuum actuator issues... and ended up doing exactly that.

Sorta, it was a delorto.

[Motu]

Don't go to manual choke, they are a hideous piece of crap, probably American as the cheapest Chinese quality is far more advanced. Those diaphragms are the idle up, and the pull off - when the engine starts it will pull the choke flap back so the engine can get some air, otherwise it will just pump out black smoke and die. The choke will be a wax element, with a couple of small water hoses connected, these will probably be blocked so the wax thing gets no water to heat it up. It should do about 1500rpm when first started, then slowly wind down as it warms up - if it's stuck at 1500 then the choke is getting no water flow.

Pull those hoses off and blow some air through them. They will be hard to get off, the alloy pipes corroded and will probably break off or at least leak. Find out why car mechanics always fuck your car up for you - now you can do it too. Your van is over 10 years past it's use by date.