Not another hot start problem!

[col320ce]

I'll measure the CO on the weekend.

When the car slows and drops a gear the revs drop to about 600 at the gear change... Is this normal or possibly the reason I am stalling occasionally?

[Pawel66]

This is automatic, right? Do you have constant speed solenoid working properly?

But perhaps before addressing that, finish idle settings with CO checks. Then move to the issue of stalling with gear in (I understand this is what you describe perhaps).

[hansr433]

I'll measure the CO on the weekend.

When the car slows and drops a gear the revs drop to about 600 at the gear change... Is this normal or possibly the reason I am stalling occasionally?

Col, what do you use as a CO tester?  I am in the market for a home use model.

[col320ce]

It is the automatic... And I think the constant speed solenoid is close to adjustment as I need to change it slightly each time otherwise the car does not drive. I think part of my problem are these linkages around the css.
I also think the power steering part of the css needs adjustment too but I think this will be the last of the warm idle things to set up.

I've got a small gunson meter and an 80s bosch unit that is massive. I haven't compared together but will do it on the weekend.  I'll take some photos of the units for you.

[col320ce]

Tuned the car to 4%CO when warm which is richer than I had it.
I used the gunson as my bosch is a massive compactest MOT unit and the pagodas engine was in the way so the sensor couldn't reach the exhaust.
Set to just over 800rpm
In gear css set to 800 rpm as well (I realise it should be a tad lower)
Now for the warm up... It's still stalling so I was going to check the CO levels at start up... But couldn't find them... Anyone know what they are or do I just do the split linkage test to assess lean/rich.
I also couldn't find the CO levels at say 2000 and 3500 rpm... Does anyone know those?
Thanks again for everyone's help

[mrfatboy]

Have you looked in the tech manual?

https://www.sl113.org/wiki/Fuel/Injection

Play around with F.I.P.i.  A lot of the info you are looking for is in there also.

[col320ce]

Thanks MrFB
That is excellent.
I ended up loosening the screws on the wrd where the oval shims are and as it is spring loaded backed out the screws until it idled OK. This was a long way and ended up making a 1mm shim.
My concern is that there are a few adjustments that are so out of 'normal' that something else is a wrong.
I still have the fip start solenoid disconnected otherwise it floods the engine.
I'll test it all again tomorrow when it's properly cooled down.

[col320ce]

Can anyone tell me if the ip lever is pushed but the thermostat (indirectly) as soon as it moves? Or is there a distance it travels before it changes to fuel setting?

I think my round washers are too thick and is the reason the oval washer I required needed to be so thick. Does anyone know the standard thickness used of the round washers? I think I'll start with this thickness (it's a PITA to change them so I want to get it right first time if possible).

Then I'll sort the oval washers...

Thanks again everyone

[mrfatboy]

When the thermostat pin moves it directly affects the rack. Take off the FIP air filter and use a mirror to look inside the hole. When at operating temperature you can see the air slide completely closed the airway. When cold the air slide is up and out of the way. Using the mirror you can watch the air slide piston move to its final position during warm up.

I can’t remember the round shim thickness. Info might be in tech manual.

Here are some more notes.


Upper Stage WRD
Removing round shims adds air and fuel only during cold start/warm up
Adding  round shims removes air and fuel only during cold start/warm up

Adding round shims does push the piston and pin assembly down and reduces the time it is open and the fuel. But it also reduces the air as well. Look close at the WRD housing where the air comes in. You will find a stepped opening comprised of three rectangular shapes. As the piston moves from the top down, the size of the opening decreases and therefore less air. So as the piston is dropping, you have less fuel but also less air.

[wwheeler]

Col,

I went through many gyrations of shimming the air valve with round shims and documented what I did. On my '68 280 engine, I found that the minimum shim thickness is around.030". That was when the air valve just barely closed when warm. Any less that, you would feel air sucking in when the engine was hot. I have .052" worth of round shims in there now and am happy with it. These are just approximations and will be slightly different on yours. But gives you a starting point. There is a specific engine temp when the air valve should shut off. If I remember correctly, it is something like 165 to 170*F.

The oval shim and the round shim do two totally different things and are not really related. The round shims as mrfatboy stated, change the temperature when the air valve shuts. The oval shims change the fuel mixture during the entire warm up process or when the WRD is active. The engine needs a certain amount of enrichment when it is cold and reduces as it warms. If you set the air valve to go off at the specified temperature it should also have the correct amount of enrichment during the warm up process.   

[stickandrudderman]

That was when the air valve just barely closed when warm. Any less that, you would feel air sucking in when the engine was hot.

Don't get too hung up on whether the air valve fully closes or not; it does exactly the same as the idle air screw so a little bleed can be compensated for at the idle air screw.
The main thing is that you should see/hear a large change in the volume of air as the coolant temp rises.

[col320ce]

I checked the round shims... There was 1.5mm there but they were all ones I made. I've now got 0.6mm in there and I've removed the 1mm oval shim I added the other day. It seems to start OK now but it's been raining so I haven't taken it out for a spin or got it fully warm.
My air was shutting off 100% before so I should be able to get this to shut off at the right temp.

[wwheeler]

I get what Stick is saying and that is correct. Not a big deal. Being that the air is being drawn in through this tiny air filter though, I wanted to minimize the amount of air so not to prematurely clog the filter. Plus that would also indicate that the pump could be ever so slightly richer. Mine still does have the smallest amount of air being sucked in and probably due to wear between the air valve and the cylinder.

I think as long as the WRD is functioning as it should and you shim it so that it shuts off at the specified temperature, the rest follows suit. The main reason to check the air draw is to determine if your air valve is stuck in the open position.