'90 Suzuki Vitara runing rich

[jeffers]

Can anyone direct me to the mixture screw on the carby of a 1990 Suzuki
Vitara, please?

Or suggest any other reason it might be running ridiculously rich.

Although the seller said it was just a faulty auto-choke, I bought it
expecting to rebuild the engine (oil rings), but have since noticed that the
black crap is all soot and no oil (whew). I found the vacuum hose to the
initial choke diaphram was leaking, and have replaced it with a big
reduction in the soot (zero at idle), but at revs its still spitting out a
bit.......or could this just be the exhaust system still full of crap. Its
unregistered at the moment or I'd take it for a highway run to see if it
cleans out the pipe.
Any serious suggestions appreciated.

Thanks

[A.M.Suzuki]

----- Original Posting -----

"jeffers" <webwizard@netspace.net.au> wrote in message
news:dbcq6t$25a7$1@otis.netspace.net.au...
> Can anyone direct me to the mixture screw on the carby of a 1990 Suzuki
> Vitara, please?
>
> Or suggest any other reason it might be running ridiculously rich.
>
> Although the seller said it was just a faulty auto-choke, I bought it
> expecting to rebuild the engine (oil rings), but have since noticed that
the
> black crap is all soot and no oil (whew). I found the vacuum hose to the
> initial choke diaphram was leaking, and have replaced it with a big
> reduction in the soot (zero at idle), but at revs its still spitting out a
> bit.......or could this just be the exhaust system still full of crap. Its
> unregistered at the moment or I'd take it for a highway run to see if it
> cleans out the pipe.
> Any serious suggestions appreciated.
>
> Thanks
>
>

Three things to check:

1. The tension on the choke strangler plate may be too high - it's
meant to richen the mixture for a second or two immediately
after start-up, then vacuum drags it open to stop the mixture
remaining too rich. This, I'm guessing, is what you replaced
the vacuum hose to.

2. The choke unit is hot water fed and is probably blocked. Of
course, if the thermostat is jammed open, the engine will not be
getting hot enough anyway (supposed to be about 2/5 on the
scale) and the choke won't be coming off fully.

3. The exhaust manifold is cracked and the stove pipe is feeding
rich, sooty fumes back into the carby, blocking the air filter,
making it run even richer (nasty, vicious circle here). Remove
the stove pipe and the air filter to eliminate this as a cause.

4. The fuel pump has failed, with fuel filling the sump (not
common, more common is the fuel pump leaking oil) with the
result that the breather system pours hugely rich fumes into the
carby (and the oil level will be high!). Remove the air filter lid
to eliminate this possibility.

The mixture screw is on the rocker cover side of the carby and is
supposed to be adjusted only with a special tool (actually, it's
just about impossible to do without the special tool due to the
lack of room. I'd leave this as a last resort though. Good luck.

--
Athel, Perth (WA)
'90 AA34S, '84 G11R, '00 SXV20R