Stalling Issues 1980 450sl
 

Aside from the previously posted braking issues I am also fighting a stalling issue. I have read through several of the forums on this so far and cannot fix this problem as of yet with the previous suggestions. I have replaced the following items in the fuel delivery: fuel pump and filter; fuel relay; all injectors and sleeves. In the ignition dept. I have replaced the following: battery; coil; distributor; rotor button; wires; plugs. In the process of trying to find a single sensor that was bad I proceeded to unplug them one by one to try and notice a difference. I have found that if I disconnect all the sensors in the top of the motor there is no difference in the operation of the engine than when they are connected. I can only assume that this would mean whatever they are connected to is my problem as that controller is not functioning correctly by using the data of the sensors to regulate the fuel delivery? I am guessing that would be the ECM or ICM? Whatever the term is for electronic control for this vehicle?

assuming it is a Kjet
if it is stalling after starting you first need to check the warm control pressure and system pressure .
Kjets need systematic evaluation of each component , and then a fix


too high of warm pressure will cause engine to lean out and die
too high or too low a system pressure will cause the air fuel mixture to be incorrect

Perhaps a few words of description of the "stalling issue" could be of aid.
Is it a cold start problem?, a warm-up problem?, a hot-start problem?, a hot idle problem?, a "shuts off during cruise" problem?, etc., etc.

Thanks for the replies, I have ordered a tester kit from Amazon and should have it by tomorrow. I will see what the pressure settings are at the various locations and move on from there. I will let you guys know what I come up with. Thanks again. It seems the language is not the only barrier I have with Germany, their technology is something else to understand. :rolleyes:

Ok, my pressure gauge came in today, and it looks like I have low system pressure. I am only seeing about 50-52psi on the system pressure. I am assuming that I have hooked it up correctly as there are limited sizes on the fittings. I have attached a pic with the setup if someone can confirm this I would greatly appreciate it. After warm up to 80deg Celsius there was no change in the pressure, car wont stay running long enough to really get any long term measurements. But, the pressure held steady after shut off, so there is one plus, I guess.https://i.imgur.com/2sZyJFv.jpg

New day. Started it up and pressure climbed up to about 70psi. Running and idling well, with the frequency valve disconnected. As you all can see in the video as soon as I connect this valve the engine stalls out and dies. It make an awful buzzing sound when plugged in so I am assuming this part is faulty.https://youtu.be/DFYJscazmxg

I was told I had the pressure gauge set up wrong, so I reconnected it the way they recommended but did not change the outcome of the stalling when connecting the frequency valve back up. https://youtu.be/vCbucDUxB-Q

Well, it looks like my issues are actually coming from the back. I have drained the tank again and it appears there is still a lot of debris in the tank from the car sitting for several years. I imagine that the sediment is just taking a little time to collect around the screen and starving out the engine of fuel. But, I need to perform a volume test to confirm this. Does anyone know the best port to use on the fuel distributor to test this theory? I tried to run a line straight from a clean gas can into the pump and since this is a recirculating system of course the original line coming from the tank was full flowing into my catch basin and drained my gas can too quick to really get a good test. Thanks in advance, I think this beauty is almost back on the road!! I am getting very excited.