solex 4a1 EFI replacement> Powejection

[koan]

There are two vacuum connections to your distributor.

One is normal vacuum advance from the port on the throttle body.

The other is tied up with idle speed compensation when A/C compressor is on, that's the connection visible on your first "after" picture. It connects to a vacuum solenoid that's actuated when the A/C compressor clutch pulls in. It gives about 10 degrees more advance at idle and increases RPM to compensate for the compressor load.

koan

[davidguarin]

thanks koan,
by the way, where is the vacuum solenoid placed? on the ac compressor?


David

[Takernz]

sorry for hi-jacking your post Daivid but this will help you, I have the same question as you, this is vacuum solenoid switch that Koan was talking about. Koan, in this photo, to where these numbers(1,2,& 3) are connected to?  


I had this one in my 280S mounted in the left side inner fender but no vacuum connections but it did have electrical but not sure it's working.

[koan]

thanks koan,
by the way, where is the vacuum solenoid placed? on the ac compressor?

On mine it's mounted on the firewall.

I have the same question as you, this is vacuum solenoid switch that Koan was talking about. Koan, in this photo, to where these numbers(1,2,& 3) are connected to?

That's what the current version vacuum solenoid looks like, with three connections, vacuum in, out and a vent.

The originals look like this, the three cylindrical objects side by side.

They have only two connections vacuum i n and out, vent is at the top.

No idea on what the connections are on the new style, but on the old type in and out can't be reversed. They are called "changeover" valves in the books"

koan

[Takernz]

That's smogged-equipped version of the vacuum switch, mine is Euro version. I'll check this thing to see if it's working.

[koan]

That's smogged-equipped version of the vacuum switch, mine is Euro version. I'll check this thing to see if it's working.

The picture of three valves was just to illustrate what old ones looked like. The idle adjust with A/C is nothing to do with smog or euro or whatever, if the car has A/C it has some sort of idle adjust.

koan

[davidguarin]

there has been a while... after a couple of problems fitting the carb it is finally done.
Due to the high customizability (not sure if that exist) is really easy to fit it into the engine parameters.
it is still learning and adjusting the fuel curve, so for now i not sure about the improvement in fuel consumption. the throttle is awesome, the engine response is very smooth the cranking is great. Air/ fuel ratio : 13,7 MAP  at idle 35, VAC -11
for now i ll keep testing.
according to the engine specs the torque is about  220 at 5000 rpms  for the 280s and about 230 for the 280se, having the same engine and the main difference is in the carb, so i'm trying with 230 let's wait to see what comes.
this has been quite expensive and time demanding but the results are pretty promising.
here some pics:

[Hit Man X]

Wow, I really like this idea over spending $1000 for a JAM Engineering conversion kit!  I LOVE the fact it still can utilize the factory MB air filter assembly

What did you have to modify, if anything, to have the throttle body system bolt in?  Simply install the spacer plate and that was all?

[davidguarin]

hi,  just uploaded a video of the engine running idle,

http://youtu.be/6hZwd-YBlII

in summary this is what i have to change:

Just match the carb adapter because the intake bore is not actually a spread bore, so the adapter needs some drilling.
remove the mechanical fuel pump and get an electric fuel pump to match the injectors requirements
fit the water temp sensor,
and that was it, the throttle body fits just right.

the MSD box is not really necessary but i had it and really want to try.

i'm not sure if that engine sound is actually a knocking sound, what do you think?

[1980sdga]

Excellent job!  From the pictures it looks very similar to a US type spread bore.

That's amazing!

[davidguarin]

Hi guys,

it has been a while.
Finally it is working fine, the self learning feature is amazing.

According to the m110 engine data sheet, the top torque is 220. this was my starting point to make the adjustments.
The change of the solex for a 4 barrel like injection system increase the amount of air coming into the engine from aprox 350cfm  to 750cfm or more (like a boost). Now the fuel is running at 45psi and 4 injectors are putting this high pressure into the manifold.

For now two big findings:
1. According to the ECU the engine is using 20% more fuel that it supposed to, this amount of fuel put the torque close to 240, it may seen just like numbers but you really feel it when you hit the gas, ill upload a video of a 0-100km/h run.
2. Fuel use. the ECU is still learning the fuel curve to keep a preset air/fuel ratio. for now it is in 17MPG in the city, the best it has ever done.

I know it was quite expensive, but i have enjoy a lot doing this project, and i have learn lots about the electronic fuel injection....

i just love this car. 

[koan]

Sounds like you've enjoyed the project.

The preset air/fuel ratio you mention, is that set for all conditions or is it dynamic/intelligent , like "we're cruising at 3000 RPM at part throttle, I'll go a bit lean" ?

koan

[Big_Richard]

This is just pure awesome.

I love technology and I love the fact that this conversion throws in some modern technology and allows you to tune a w116 with a laptop and looks factory. I am speechless. (almost )

If only there was a factory looking K-Jet upgrade