Sat for two years because it would idle but die on acceleration. Brother has given me the car. I replaced the fuel pump and filter. got fuel now to wur and cold start injector and in and out of injector body. No fuel to injector lines. I feel resistance on the air flap after it pressures up. I can pour gas in and it runs smooth for a bit so I know it is fuel delivery and is running on the cold start injector shot intially. What controls fuel delivery to the injector lines? I have studied the manual to no avail.
Thanks

 

I'm going by what I know about my Porsche 924 injection system (1982) - the injection system depends on intake vacuum to open the circular throttle plate. Even small leaks in the shroud leading to the fuel distributor can cause poor throttle response (or none at all). I looked at some 450SL diagrams and it seems to have a similar system. It sounds like you're getting fuel to the fuel distributor, but its not getting to the injectors, so look for vacuum leaks. This might be a function of age deterioration in the plastic. I hope that this helps. Please keep posting - Peter

 

Fuel pump relay

 

It's probably not the pump relay if you're getting fuel to the cold start injector and fuel distributor. Here's my recommendation: the best source of information for this type of older injector system is Porsche 924 Garage & Register home. I'd join and post complete info about the system type and problem. The forum is very active and knowledgeable about the German injector system in cars from the 70's & '80s. Although it's dedicated to the Porsche 924, I believe that they will help with practical trouble shooting and solutions since the systems are similar. The system is very durable once you get it up and running. Good luck. - Peter

 

Thanks! I will check it out.

 

in my case it was the ignition distributor. Check the cap under a magnifying glass. hairline cracks on the interior laquer finish is tell tale. Why that does thid I don't knor but a new distributor (not expensice) solves all your problems.

 

I assume that you're getting gas to the regulator since the cold start injector is working and that you confirmed that there are no vacuum leaks in the intake housing. So a rebuilt or new fuel distributor might be the right answer.
I don't know if it can be cleaned internally. Since the 450SL CIS system is somewhat common to German cars of that vintage, I'm providing a few links - the first is a link on general function and the second is a trouble shooting guide. The others are Mercedes specific. Hope that this helps.

CIS Injection
CIS-E: Troubleshooting and tuning

EBSCOhost Login
ION_SYST.htm

You want to look at the EFI info, 07.4:
Mercedes-Benz Model 116
W116 : Mercedes-Benz S-Class - 280S, 280SE, 280SEL, 300SD, 350SE, 350SEL, 450SE, 450SEL & 450SEL 6.9
W116 library : Mercedes-Benz S-Class - 280S, 280SE, 280SEL, 300SD, 350SE, 350SEL, 450SE, 450SEL & 450SEL 6.9
W116 Service Manual : Mercedes-Benz S-Class - 280S, 280SE, 280SEL, 300SD, 350SE, 350SEL, 450SE, 450SEL & 450SEL 6.9