jvandyke

I searched, honest I did. The FAQ link to the rat's nest removal tutorial is broken BTW.
So, new to us '82. Rat's nest is gone. Car seems to run alright, not much running yet though (tires and brakes first). Choke **** won't stay out. I understand there is some sort of electrical magnet thingy that pulls it back in, run by ECU and temp sensors, carburetor heater and good Lord knows what else. Rat's nest gone via PO, many other "mods" as well. I'm tempted to just install a straight mechanical **** and "retire" this (seemingly) unnecessary clutter. What's easier then a fully manual choke (as long as you remember to "unchoke" eventually!).
At the moment, if you hold the **** out and carefully use it to regulate rpm, eventually you can let it back in and get a good idle and all is well, just be nice to not have to hold it but rather have it stay were set, ya know? Maybe as simple as removing a return spring somewhere?

PercentSevenC

Back when I had a stripped stock carb and a next-to-nonexistant wiring harness, I would use a coin or hex nut or similar small object to hold the choke **** out until it warmed up. I would keep a few things of different sizes in the ashtray so I could have the choke at different positions.

(I like the Fiat X1/9 avatar, by the way. )

t_g_farrell

iTrader: (1)

The choke has a magnet that holds it open as long as the temperature is below
~150 F. This is sensed by a sender on the back of the waterpump right where the
tstat is located. Its just 2 wires that come off the standard engine loom. If the PO
messed with it, it may not be hooked up or the plug might be missing altogether.

So the way it normally works, is you pull the choke and magnet is energized and
holds it in position. Once the temp comes up the magnet loses its charge and it
pops back in. It works very nice and you hardly have to think about it. Its really
worth hooking it back IMHO.

ztfdrake61

I did similiar to PercentSevenC, I used a couple pieces of scrap plastic about 3/8 inch thick and just kept it behind the choke lever till it warmed up

I eventually fixed the issue by resoldering the connector though, much nicer

jvandyke

okay, wiring diagram looks pretty complicated but I'll try to make it work before I just go straight "manual", Must be magnet is not getting it's juice so I'll start troubleshooting.

j9fd3s

iTrader: (3)

step 1 is to open the hood and see if the sender in the back of the water pump housing is hooked up

step 2 is to hook it up.

Twilightoptics

iTrader: (1)

Actually it's the other way around guys.

The magnet pulls the choke closed. With power, the magnet is disabled allowing the choke lever to stay pulled out.


Temp Switch back of the waterpump: The switch is NORMALLY CLOSED. One wire is from the Emissions ECU to the temp sensor on the water pump housing. Other wire from temp sensor goes to the Choke/Check relay. Very simple to follow in the wiring diagram.

I have no rats nest, and recently removed the emissions ecu. All I did was tap into 12v ignition power at the engine harness connector, and sent power to one of the A/C Relays and split off to the temp switch. Which is all you need to do when the rats nest is removed and you still want a/c and choke cable to function properly.



With key on, below 158deg..... the temp switch allows 12v power to reach the choke/check relay which keeps the choke out. When it reaches 158deg, the switch opens, and no more power to the relay, the pull returns back in.

t_g_farrell

iTrader: (1)

Umm, I don't think so.

From the manual:

When cold engine is started with assist of choke ****, the
**** is held in pulled position by the choke magnet. Full release of
choke **** is achieved as engine coolant temperature reaches 158F
(70C). The no. 1 water temperature switch stops the flow of
electrical current to magnet and the choke **** is released.

jvandyke

No wonder this noob is confused!
Where is the ECU located? I suspect it is gone. I'll still try to get the old system functional first, as it interests me, when interest turns to frustration; full manual choke ****!

DivinDriver

iTrader: (15)

Sorry, but this is incorrect. The magnet holds the choke in the extended (pulled out, closed) position when power is applied to the magnet. When magnet power is removed, the choke cable is allowed to be retracted by the spring on the choke butterfly shaft.

DivinDriver

iTrader: (15)

ECU is under the dash, above your left foot when in the driver's seat. If it's missing, call the Pope - - there's been a miracle!

Pretty hard to run the car without one, unless the entire electrical system has been re-engineered.

74RX4

iTrader: (10)

ECU is under a metal plate under the carpet on the passenger (right) side floor. A jumper wire between the two terminals in the #1 water temperature switch harness plug will make the choke **** stay in place all the time. Plug has a Blue/black wire and a Blue/white wire. If the jumper wire doesn't work, either the ECU is not sending a signal or the wiring is disconnected. Wires on the water temperature switch often break at the switch.

Twilightoptics

iTrader: (1)

Hmm this seems backwards as far as electrical magnets go in my experiance. My mistake! :O(

Either way, I did have the wiring and the switch functionality correct, which was more the point I was trying to get across. As well as what the **** does at what power times.

If you give power to the water temp feed wire from the ECU, the choke will function correctly and still use the water temp switch! Why does everyone keep trying to bypass the switch and the automatic pull off function??!?!?!?!?!?!? It's just a different wire to give 12v key on power to!

JoeNoble

iTrader: (6)

I wired mine through my rear defrost switch as it no longer works for no apparent reason and already has 12v so I just pull out the choke then flip on the switch and just flip it off when she's warmed up.

jvandyke

Thanks again everyone.
I will look for the switch/sensor on the water pump.
Let's see if I got this, the ECU sends power to the Choke Switch and Magnet through #1 Water Temp Switch (on water pump housing). Switch gets to 158, opens the circuit and 12v stops going to Choke Switch and Magnet, de-energizing magnet, with allows spring tension on cable to pull choke back in.
So, if I want the **** to stay out on it's own but go back in when temp is reached. I need to check for 12v to #1 Water Temp Switch (LB wire, looking for color code key now) and 12v also on LW wire (when cold). When hot voltage to LW should stop.

Does the act of pulling out the choke **** initially tell the ECU to energize the circuit? Through the LR wire to pin R of the ECU?
What's up the other 25 things in the circuit? to name a few, Hot Start Relay, Carb heater, Choke an Check relay......
Assuming there isn't 12v at #1 Water Temp Switch from the ECU, I have to start backing up I guess.

DivinDriver

iTrader: (15)

Not according to the factory wiring diagram.

Connector B-01 for the ECU is left side, high up under the dash. Same place it is on the SAs.

The switch element in the choke cable box (part of the cable, right behind the dash) powers the Carb Heater, so the heater only gets power when the choke **** is out. I believe that also sends a signal to the ECU (on pin C) indicating that the choke is pulled, but I'm not 100% certain of that - would need to consult FSM.

Hot Start Relay sits on driver side inner fender rear; has a mechanical cable that goes to the throttle linkage, pulls the throttle open when starting a hot engine. Prevents flooding on hot starts. You can do the same thing by always giving full throttle when hot starting.

Choke and Check Relay primarily is there to perform your idiot light est for you, though choke magnet power goes thru it as well.

Carb Heater is in the round metal shell at the rear of the carb choke linkage; heats the bimetal strip which in turn is responsible for adjusting choke closure angle based on ambient temperature; essentially arranges for time-delayed relief of choke closure angle while the engine heats up.

jvandyke

Thanks again for helping. Hope to help a noob myself someday.
I had it backward then, the last part of my previous post. ECU sends power to Choke and Magnet switch via LR, you pull ****, closing circuit, power goes out to carb heater and also back to ECU via BR wire at pin C, ECU (from pin D) sends 12v through #1 Water Temp Switch via LB wire back to Choke and Magnet switch, energizing the magnet, holding **** out. #1 Water Temp Switch heats up to 158, opens the switch, stops the 12v to the magnet, it shuts down allowing linkage spring to pull the choke back in. Maybe.....

74RX4

iTrader: (10)

You're right of course. I forgot we were talking about an 82.

7aull

iTrader: (2)

All good stuff - appreciate the discussion, esp since MY SA choke holds for about 30 sec on a cold start then pops back in
So for me the idea of shorting out the connection at the water-pump sensor thus (if I understand all being said here) allowing the choke to stay out till I manually push it in...

Thanks
Stu Aull
80GS
Alaska

jvandyke

In our case, I looked at the #1 Water Temp Sensor at the water pump (pretty darn sure I found the right one) So I decided to touch it, oops, one wire fell off in my hand. I think I will just put 12v to the magnet to see what happens, then try to fix things.

Here's the wiring in question.

jvandyke

I put 12v on the broken off wire and the choke **** would stay out, removed the 12v and **** get's sucked back in and stays. I will fiddle with switch and hopefully fix it or I'll just put switched 12v on that and forget it.

jvandyke

Or rig a switch like joe mentioned above.

j9fd3s

iTrader: (3)

that's actually easy, you unplug the sensor in the water pump and jumper the wires on the harness plug

DivinDriver

iTrader: (15)

Or you could just replace the faulty sensor...

boyee

iTrader: (3)

This discussion rocks!

Could anybody explain why my choke lever will not stay out as well as when manually holding the lever out, I do not notice my RPMs any higher than idle?

I can visibly see the choke plate closing when I pull out the lever on the carb so my cable linkage is working. I checked my Engine fuse and choke check relay I can hear working (dummy lights are on and working too). My bimetal coil carb warmer piece is hooked up also.