Throttle Microswitch....anyone know about it?

[mmacneill123 0]

Hi folks, having a problem where i am stalling randomly once the engine is warmed up and stopping at roundabouts, queueing in traffic etc. When i had the car in for something else a month back, the mechanic mentioned he had cleaned the microswitch on the throttle and see how it goes, it went okay but has re-occured so am wondering where the switch is and how do i get a new one :-) ! It is a 9A 2L/16 :-) Any general advice on how you remove the electrical connectors, i am Rado-ignorant having only recently re-entered from the Rocco world :-)

 

Cheers

[dubweiser 0]

Did you check the isv?Its worth cleaning that to see if it helps.Also from another thread with similar problems...."If the engine isn't hunting when cold or hot, the CO is correct. 16Vs run best at 2.0 % CO.

 

To achieve 2.0%, disconnect the famous "red lead" spade connector behind the coil (see fig:1 below) (after the engine is at temp), pull off the breather hose and block the airbox hole. Start the engine and the revs should plummet, if they don't, the idle valve is shagged and you're idling off the bypass screw alone. Now, with the engine running, turn the idle screw (fig: 3) up until you get 950rpm +-50.

 

If the idle wanders or is lumpy (engine visibly rocking), insert your LONG 3mm allen key into the CO screw (fig :2) and turn it anti clock to weaken. Just prior to the engine cutting out, turn the key clockwise in 1/8th turn increments until the idle smooths out. Eventually, the engine should settle to a nice, steady idle. This will be 2.0% or very close to.

 

Switch off and reconnect everything.

 

Take it out for a run and when you dip the clutch, the tacho needle should gently fall to 1000rpm, not plummet. If after all that it's still missing and rough, investigate air leaks around the inlet manifold and the various vacumn hoses.

If you ever need to find the controller for the ISV it's the black box with 'VDO' marked on it that's clipped to the back of the ashtray or (if someones been fiddling), shoved behind the dash in a random fashion!

 

If you're really unlucky and the above instructions don't sort out your particular idling issue,check that the three senders on the end of the head, under the distributor are working, 2 of these control the ISV and the other is the temperature gauge sender - the senders are all the same so as long as your temperature gauge works, you can swap the wires to make sure all 3 senders actually make the temp gauge register, obviously if one doesn't work, there's your faulty sensor."

[aide 0]

You can't adjust co2 on two litres manually, or you shouldn't as the adjusting hole is sealed. Also you ought to use an eg analyser as that method above is a get you going quick fix and not wholly accurate, i never got it accurate using it anyway!

 

The micro switch is fixed to the side of the throttle body by two small screws form what I remember, it should be activated when the throttle body is closed to operate the ISV. Theres a threaded screw for adjusting,it's also simple enough to test the microswitch with a multi meter, and if it's faulty maplin sell them.

[dubweiser 0]

It wasnt my thread,as i said it came from another one on the forum.However,you can adjust it on a 2litre because i got mine set up up like this years ago and it has run fine since.

[aide 0]

Yes mate recognise it from a thread back in the 90's and I know you 'can' but the point is you 'shouldn't' as it's sealed with a rubber grommet from the factory on a 9a, mixture is controlled by an actuator on the side of the metering head using the ecu inputs from the lambda unlike the kr which uses electro mechanical sensors under load and the adjustment screw for base idle. If the mixture is out on a 9a it's usually because some other link in the system is faulty.

[mmacneill123 0]

Cheers guys, this gives me something to work with :-)

[davidwort 0]

I have to agree with aide, far too many 2.0 16v's have had the factory calibrated metering head messed about with by mechanics who think the car is K-jet as it looks similar, usually to attempt to correct a running issue that is actually caused by a lambda or temp sensor being faulty, this then results in the car never running right and struggling to meet emissions. More harm done than good I'm afraid, trouble is hardly anyone knows the correct fault diagnosis and testing procedures for the KE-jet system on the 9A engine and most dealerships have long since thrown out the workshop manuals, even if their staff could read :)

[mmacneill123 0]

I gave the two switches on the throttle body a clean and all the obvious grounds i could see on the block and the idle has smoothed out nicely but still have the problem it seems to splutter after it has been running for a few minutes, recovers, splutters again after another couple of minutes....any suggestions?? :-)