On the relay, my 3.0 does not have such a relay, but it does not have air auxiliary valves neither
carbs are of several different versions
carbs are of several different versions
2800cs zenith wiring
- Thread starter Baikal Bimmer
- Start date
Maybe you know how the automatic choke works.
this engine requires a curious sequence to start well
The first thing you should do with a cold engine is to check the carburetors.
When the engine has cooled from its hot normal function you should be able to see the two primary buterflies of the two carburettors fully open.
if then (with the engine off) you press the accelerator only once, both throttles should close at once like a mouse trap
this engine requires a curious sequence to start well
The first thing you should do with a cold engine is to check the carburetors.
When the engine has cooled from its hot normal function you should be able to see the two primary buterflies of the two carburettors fully open.
if then (with the engine off) you press the accelerator only once, both throttles should close at once like a mouse trap
Baikal Bimmer
Well-Known Member
After following Hb Chris’s instruction I adjusted the water choke. The car was harder to start, but while it warmed up it now idles at 1200 rpm, when it reached operating temperature the idle climbed back to 2000 and stayed there!
I shut the car off and pressed the pedal but the chokes did not snap shut
now it's time to start the engine
automatically both primary butterflies should open 2.8mm due to engine vacuum effect
the engine will go up to 1400 rpm and will stay there while a bimetallic spring inside the choke begins to heat up due to the combined effect of the electrical resistance + the effect of the coolant
the bimetallic spring will move the primary buterfly progressively toward a fully open position, and hence revs will increase.
then you give another kick at accel pedal and this disengages the choke
automatically both primary butterflies should open 2.8mm due to engine vacuum effect
the engine will go up to 1400 rpm and will stay there while a bimetallic spring inside the choke begins to heat up due to the combined effect of the electrical resistance + the effect of the coolant
the bimetallic spring will move the primary buterfly progressively toward a fully open position, and hence revs will increase.
then you give another kick at accel pedal and this disengages the choke
following that instruction you did not adjust the water choke but the tension of the bimetallic spring that operates the primay buterfly (maybe in your case it was too loose)
as you did not tell all the details it is hard to follow
when engine is still warm the pedal will not shut the buterflies
i think that you should follow the procedure from cold engine now to see how it works, take pics and notes)
Baikal Bimmer
Well-Known Member
Ok I will wait for it to cool and try again
Thanks for trying to help I appreciate it
Baikal Bimmer
Well-Known Member
While I wait for it cool does this green and white wire need to be reconnected or connected to something?
Those are green/white dot, I would leave them alone without the relay. You must still have power to the green/white stripe or your car won’t run.
As deQ says, you need to turn the choke housing (the bimetallic spring is inside) so both are upright then turn back and forth a bit to see if it moves the choke butterfly. As water hoses are attached, you need to loosen the 13mm nut just a bit or coolant will spill out but it will allow you to twist the larger housing. There is an arrow/mark on top that says Rich, it is your guide.
Baikal Bimmer
Well-Known Member
You mean these green and white?
If so I have tested several times and they definitely do not have any current, whereas the previously shown green with white does have 12v
On my car this wire connects the idle solenoid, enriched, and water choke but does not seam to have any power at either carb!!
I am very confused,
If it goes to the idle valve key must be on for it to energize and open the valve or car won’t run, period.
Baikal Bimmer
Well-Known Member
I just disconnected all wires to solenoid and carb and the car still starts up and rune, how can this be?
Wow, I’m stumped.
Baikal Bimmer
Well-Known Member
Tell me about it, I feel like I am chasing my tail here.
Soon I will be putting an m90 with a dogleg in the car, but until then I wanted to drive the car
Even without chokes car should run fine unless chokes aren’t opening. The electric circuit to the choke housing cuts off the choke when temp registers high enough on the sensor under front manifold. And those enrichment devices do very little if anything, again only when cold. Maybe the idle jets are stuck open though I’ve never heard of that. They are on forward side of the carbs and are a slim round cylinder With a spade on the end.
You need to make sure throttle linkages tip in evenly at the same time, any movement of one without the other is not good. Are they closed at rest? There are adjusters on each carb that are very short but adjustable. Are there any orifices that aren’t capped off like the retard nipples on driver side of carb if they have been removed. Advance nipples are on valve cover side. You don’t want any vacuum leaks. The idle screws need to be at the same setting, they are under the carbs in valve cover side. Again, on the choke housing there is small vertical rod attached to the butterfly and goes down into choke housing, it needs to move freely, I had to shoot PB Blaster there and move them to free them up.
You need to make sure throttle linkages tip in evenly at the same time, any movement of one without the other is not good. Are they closed at rest? There are adjusters on each carb that are very short but adjustable. Are there any orifices that aren’t capped off like the retard nipples on driver side of carb if they have been removed. Advance nipples are on valve cover side. You don’t want any vacuum leaks. The idle screws need to be at the same setting, they are under the carbs in valve cover side. Again, on the choke housing there is small vertical rod attached to the butterfly and goes down into choke housing, it needs to move freely, I had to shoot PB Blaster there and move them to free them up.
good thing to wait until cold engine again. you have to check your starting point from fresh, and if you share that with us we can probably help better.
in order to organize my answers i will open two different chapters, hope that you will agree:
one the electric issue of the harshness and so on, and second the mechanical things and basic setups and carbs synchro
1- as to the first one:
electrically i will not be worried about the choke resistance now, it might be slower, but the coolant thermal effect will work and act on the spring and buterfly
i am very much concerned about the no electric power that you refer on the iddle solenoid, this is puzzling, the iddle solenoid acts like an electrovalve for safety, no power means valve closed, and it should kill the engine Air to fuel intake; iddle solenoids are easy to remove and check, from top of my head a 9mm spanner will help lose free the solenoid body and then you can unscrew them by hand; clean the tip with gasoline and then check with a positive lead in the spade and negative in the solenoid body, you must hear a click and see it works
(these are old cars, many years mean usually many possible dirty tricks, i have seen some of them in some pairs of carbs that i have overhauled, so expect the unimaginable)
for pictures take a look to some DIY on carbs i did some years ago with help of @rsporsche and others:
hunting the carbs problem
hunting the carbs problem, zeniths so, it has been a long time up and down with the carbs really fed up with them, no way to synchronise both, to get a good and smooth iddle and when the iddle (thanks to porsche61, and stevehose among others) was reached, the transition (1800 to 2200 rpm´s)...
e9coupe.com
2- on the second thing
this kind of things get a lot of help from pictures, else it is very difficult to understand, lets try to make it very graphical:
on the previous action on the bimetallic spring, see here the basic setup of the choke position, the serrated mark on the choke barrel should point at the mark in the choke body; as we saw in your pictures (deducted by the position of the electric spades), you can tell that your spades were far in the direction of the green arrow, meaning that RICH-er so higher revs that you have now corrected.
the carbs do have a collection of basic settings, we call them "table settings", those might have to be altered during the engine tuning when the carbs are installed in the car, but basic table settings are key; some of these settings can be done now, others will require the removal of the carbs
obviously i would recomend a basic cleaning of the carbs at least to get all elements working freely, if you dont feel like removing the carbs from the engine the spray of light cleaning oil is a good advice, i would go after that with a brush and finally some compressed air to remove the excess.
this kind of things get a lot of help from pictures, else it is very difficult to understand, lets try to make it very graphical:
on the previous action on the bimetallic spring, see here the basic setup of the choke position, the serrated mark on the choke barrel should point at the mark in the choke body; as we saw in your pictures (deducted by the position of the electric spades), you can tell that your spades were far in the direction of the green arrow, meaning that RICH-er so higher revs that you have now corrected.
the carbs do have a collection of basic settings, we call them "table settings", those might have to be altered during the engine tuning when the carbs are installed in the car, but basic table settings are key; some of these settings can be done now, others will require the removal of the carbs
obviously i would recomend a basic cleaning of the carbs at least to get all elements working freely, if you dont feel like removing the carbs from the engine the spray of light cleaning oil is a good advice, i would go after that with a brush and finally some compressed air to remove the excess.
here you can find more information and pics of my last set of carbs:
e9coupe.com
zenith carbs rehab
doing this and that carbs come and carbs go, they get cleaner, in better shape, with new bits, and they go
e9coupe.com
from cold engine and before touching anything (do not press the throttle pedal nor linkage), do not start the engine
take a picture of top view of both carbs, to show the position of the primary buterflies, they should be wide open as a result of previous day warm engine, like this:
now kick the acel pedal or the linkage and look at the buterflies, and take a picture, both buterflies must close completely, like this:
now start the engine without touching the acel pedal, simply with the key, if the engine starts the buterfly should look like this: an opening of 2,8mm
if all this happens, read the rpms, and report
if any of this fails report and we will try to help
take a picture of top view of both carbs, to show the position of the primary buterflies, they should be wide open as a result of previous day warm engine, like this:
now kick the acel pedal or the linkage and look at the buterflies, and take a picture, both buterflies must close completely, like this:
now start the engine without touching the acel pedal, simply with the key, if the engine starts the buterfly should look like this: an opening of 2,8mm
if all this happens, read the rpms, and report
if any of this fails report and we will try to help