Cavalier high idle speed problem

Hi all

Recently bought an old mk3 cav with 1.6 carb (16SV engine) as a winter hack as it was going cheap and had lots of MOT.

I am however slightly puzzled by the idle speed. It will remain high for some time even after the choke has gone off. I can see this because the choke plate is fully open. It eventually drops to normal, but if I stop the engine and restart it a few minutes later it will sometimes go high again for a minute or so. Blipping the throttle has no effect.

Upon inspection, I see that there is a wire going to the choke housing, and another goes to some sort of solenoid valve on the left (as per car) side of the carb. What do these wires do? It's a pierburg carb I think.

Any ideas anyone?

I didn't want to go ripping the carb apart with no idea of the cause, given how sweet it otherwise runs.

cheers

-- The Dervboy

Reply-to address is valid as required by my news server, but is a spam box and is never read. My real e-mail address is thedervboy{at}btopenglobe{dot}com (substituting "globe" with "world").

Reply to
DervBoy
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I'll have a look for that as soon as I can.

Something else I'm unsure about is which way around the two vacuum pipes on the airbox which feed the hot air intake valve should go. I took the airbox off last night and failed to note which pipe goes to the vacuum valve and which goes to the carb.

One way around seems to make a permanent cold air intake, the other a permenant hot air intake.

At the moment, as viewed from the drivers seat, the pipe from the carb is on the right hand stub of the airbox, the pipe going to the vacuum valve is on the left hand side. Anyone know if this is correct? It seems to make it stay on cold air intake all the time.

BTW, the engine was fairly warm when I was testing this.

cheers

The Dervboy

Reply to
DervBoy

Well, to be slightly more accurate, the solenoid operates when the ignition is on, to permit fuel flow via the idle jet. When switched off, it springs back to block the flow. Mine would intermittently fail "off" when the engine was running - engine would immediately stall on engaging the clutch, usually at the worst place to lose power, like going round a tight corner...

These carbs seem to lean out as they wear out (arguably preferable to the other way round). My record for an 11-gallon fill-up was 528 miles. I got a little nervous the low warning light was kaput, or I might have made it to

600 !
Reply to
John Laird

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