CIS K-Lambda component clarification, 88 930

[b5aar]

Hi Guys

Just trying to confirm location and function on my 930

Driver chain cover - thermo time switch(2 wires),,,,opens/operates cold start injector(in manifold) as needed when cold


Passenger chain cover - Temp sensor?,,,brings in Lambda/oxygen sensor after warm up to change from open loop to closed loop operation



Vacuum switch (2 vacuum lines) - during warm up....prevents vacuum to retard side of distributor..hence more advance raising idle approx 200rpm for a minute or so after start up.....the vacuum line (Red) runs to my distributor and connects to bottom nipple as pictured...

the black cloth line from upper nipple distributor runs to 6 oclock (left side tee) on the throttle body....Is this vacuum advance??

The other line running from the vacuum switch connects to the throttle body at approx 1 oclock...what is that function???

[JFairman]

Originally Posted by b5aar

Hi Guys

Just trying to confirm location and function on my 930

"Driver chain cover - thermo time switch(2 wires),,,,opens/operates cold start injector(in manifold) as needed when cold"

[It only opens the cold start injector while the starter motor is being turned over and it has an internal heating element that heats it up quickly and disables it so you don't flood out the motor with fuel if the the motor doesn't start and you keep cranking it over trying to start it.]

"Passenger chain cover - Temp sensor?,,,brings in Lambda/oxygen sensor after warm up to change from open loop to closed loop operation"

[The throttle position switch on the throttle body also does this during somewhere around 1/2 to 3/4 throttle.]




"Vacuum switch (2 vacuum lines) - during warm up....prevents vacuum to retard side of distributor..hence more advance raising idle approx 200rpm for a minute or two after start up.....the vacuum line (Red) runs to my distributor and connects to bottom nipple as pictured..."

[This one is a mechanical thermovalve that disables vacuum advance until the motor transfers enough heat into it to open it. Then vacuum advance returns. The purpose of that is to keep timing retarded to a certain degree during cold start and warm up. That may not make sense to you but the reason is beacuse retarding the timing raises exhaust temperature and raising exhaust temperature increases heat in the catalytic converter so it heats up faster and starts lowering exhaust emissions sooner after a cold start.
The red vacuum line is vacuum advance and the other cloth covered one is vacuum retard.
There is an electric vacuum switch above the distributor if it's still there that blocks vacuum retard for a couple minutes after cold start to help raise idle speed 200-300 rpms during cold starts. It's wired in parallel with another vacuum switch that operates the air pump diverter valves that switchs air injection from the exhaust port nozzles to the catalytic converter.
These vacuum switches and thermovalves operate together in a balance to help lower exhaust emissions.]

"the black cloth line from upper nipple distributor runs to 6 oclock (left side tee) on the throttle body....Is this vacuum advance??"
[No it's vacuum retard.]

"The other line running from the vacuum switch connects to the throttle body at approx 1 oclock...what is that function???"
[Vacuum advance.]

Yank all that crap off and the car will run much better.

[mark houghton]

"the black cloth line from upper nipple distributor runs to 6 oclock (left side tee) on the throttle body....Is this vacuum advance??" functions as vacuum advance and boost retard

"The other line running from the vacuum switch connects to the throttle body at approx 1 oclock...what is that function???" You already answered that question....it's where the vacuum switch gets its vacuum from. That swich will open when it reaches about 150*F (I tested mine once just for kicks), and when it opens it allows the vacuum to travel down the red line to the distributor.

Been awhile since I've thought about these. Hopefully I haven't got it reversed in my mind (if so, we have buddies out there to offer corrections).

[JFairman]

oh well, you have a lot of it wrong and i wrote correct replies and the forum software copied the text style you had and screwed it all up. i don't have the patience to rewrite it all again...
I went back and added " " around what you wrote and [ ] around what I wrote to try and seperate them.

[b5aar]

thanks Jim and Mark. You guys rock. Jim when you say get rid of that crap how specifically do I do it to retain proper running. Should i plug the thermo valve and run vacuum line directly from 1 o'clock throttle body to my lower nipple advance on the distributor?

[T77911S]

the post above was a bit confusing. i saw this:

Passenger chain cover - Temp sensor?,,,brings in Lambda/oxygen sensor after warm up to change from open loop to closed loop operation"

[The throttle position switch on the throttle body also does this during somewhere around 1/2 to 3/4 throttle.]

i thought the TPS put it in OPEN loop from 1/2 to WOT and closed below about 1/2 or so.


i changed the vac hose routing on mine for the thermo time valve. i wanted a little extra RPM when cold so i plumbed the TTV in on the retard side.

[JFairman]

You're probably right. I forgot the right phrase and can't remember if it's open or closed loop and don't even know what open and closed loop means by definition.

Anyway, whatever you call it the oxygen sensor is disabled and the frequency/pulse valve inline injector goes to a set constant frequency that returns a certain amount or percentage of the fuel head lower differential chamber lambda system control pressure to the gas tank so the diaphram drops down away from the upper chamber metering orifices leading to the injector lines and more fuel goes to the injectors richening up the mixture a little.

If you remove the lambda system from a lambda fuel head you turn the 3mm allen head spring tension adjustments under the 4mm allen head button head caps clockwise a little to push the diaphram down away from the meterng orifices so the fuel head doesn't run too lean when the frequency valve is removed.
You can also adjust and balance the amount of fuel sprayed by each injector individually with those allen heads.

The control plunger operated by the air flow meter linkage from the bottom and control pressure working against it from the top is the the main control over how much fuel is injected.