Maddog I think it's fuel thats why I'am going to connect the cold start injector for enrichment. Today a tested it by manualy switching it on and it seems to provide enough fuel. At 0.5 bars the 02 sensor signal read on an volt meter registered between 0.76 and 0.84, without it the reading was 0.44 - 0.45 which is lean :(. Any suggestions on a good adjustable boost pressure switch ?

CIS-E is adjustable and should give you enough fuel to match your boost. I'm running around 12 psi in my 560 SEC with the stock CIS-E and I get plenty of fuel to support around 400 hp. The problem with CIS-E is that you may get too much fuel too early or too much fuel too late. The system is somewhat difficult to tune so you get the righ amount at the right time but you shouldn't have to modify your cold start injector on a CIS-E car or at least I didn't.

On the drivers side 560 SEC and is probably the same on your 190, US car, there is a little black box on the side of the CIS distributor and it is held in by two screws T-25. Take those two screws out and on the back side of that little black box is a brass set screw. Unscrew that brass screw. Under that screw, there is a small allen screw that can be adjusted to vary the amout of fuel your engine uses. Clockwise richens the mixture. I would only do around 1/4 turn at a time and reinstall the car. You will have to back off the idle adjustment screw around 1/4 turn for every 1/2 turn of the screw in the black box. Keep repeating these steps until your car runs with enough fuel and idles smoothly. Be careful when removing those two screws because the fuel is at high pressure and will spray out. Make sure you don't lose the two little rubber o-rings between that little black box and the CIS distributor. I lost one while my car was on a dyno but I was lucky to find it after around 1 hour of looking all over the place. Without it, your car will not run very well and it will spit fuel all over the place. Trust me......

A naturally aspirated CIS-E engine can also benefit from richening the mixture. The factory sets it pretty lean from the start but I would only adjust it around 1/4 of a turn for an optimum mixture .

Good luck.

super SEC, thanks for the reply!!! this morning a played around with the EHA(the black box) and I'm already getting good results !!! After every run (through which I monitor the 02 signal) I take off the sparks plugs. At first they were very grey indicating a lean mixture but now they are brownish/ However it will need a lot of tunning until I get it right since there is no dyno machine in my country :(

Oh ye of little displacement, you are welcome.

The ass-o-meter dyno should tell you quite a bit. Just keep adjusting and you will eventually get the proper mixture. When you think you have it right then go to the DynoJet. I picked-up around 35 RWHP by just a fuel tweek on the dyno with my SEC.

You will definetly need more fuelling!

dont bother with narrow band guages what you need to do is go to a rolling road (dyno in us?) and get them to stick a wideband on the exhuast and go for a run!

After my turbo conversion I found out I was running too lean! and I opted for a extra injector which was connected to a Scooby MAP sensor instead of a boost switch. The benefits of the MAP sensor is that it can see varied amounts of boost so it will send a signal to the MF2 (or any other programable injector controller) so you get extra fuel only when you need it! not all the time u see boost!

some pics:

http://193.63.6.63/koolvin/benz/turbo/map.jpg

http://193.63.6.63/koolvin/benz/turbo/mf2.jpg