72 350 SLC AMG No Start

[jonesin4boost]

I have a customers vehicle in which wont start. According to the customer he believes its 1 out of 20 made. Its a 72 350 SLC AMG. Well the story is its apparently had several mechanics work on it. When I received it the last shop it was at was a Mercedes dealership in which they said it needed a fuel pump. Well I found that to inaccurate. I looked over the engine as best i could considering I had no information to go off of. I found that the vehicle had a sufficient amount of fuel pressure and that occasionally it would start. I also found that the points were burnt up and the distributor was loose. I was ignorant when it came to this particular vehicle however I am pretty good at researching to find and fix problems like this one. So far I found a shocker. The ignition control module that's bolted under the left front pannel was not even wired up. This vehicle is in pretty rough shape as you can see.

What I am looking for is a lead on where to get reliable info on wiring diagrams and other useful information to accurately and efficiently repair this vehicle to a good running condition. Right of the bat I found a popular repair to eliminate or replace the ignition points. Its the Pertronix igniter 1 points conversion.
So If anyone has a jump on a good setup that eliminates this ancient technology and a good repair manual for this supposedly, customer noted 1 out of 20 made slc I would like to get it. Thanks.
Oh one other question...the fuel injection pulse comes from what....another pick up in the distributor ...a cam sensor or what other reference in relation to the ignition timing and how they synchronize. it seems strange that the vehicle was running even with the ICM not wired up. I guess the vehicle was operating on no advance except the mechanical vacuum advance in the distributor. I'm assuming the 5 or 6 wires that went to the bottom of the distributor are the pickup signal and the fuel injection reference signal is received form it. Anyways I a manual would be nice if possible. Thanks.

[Shooter]

The injectors fire from a set of points in the bottom of the distributor. They are called trigger points and they gang fire the injectors in sets of two. Check for injectors firing. The trigger points are expensive and alot of people convert to a megasquirt system instead of replacing them.

[Tomguy]

If this is actually an AMG the only thing special would be the heads & cams most likely, the rest should be a standard affair '73 450SEC with D-Jet.

First, are the injectors blue or yellow? Blue = 4.5 (450), yellow = 3.5 (350). This would matter if you need to replace the ECU for the D-Jet - and that's probably it other than internal engine components (the crank's different, as is the timing chain & rails - most of the rest including cams, pistons are interchangeable; 3.5 heads fit a 4,5 but give higher compression and vice-versa). A standard R107 manual covering 1973 should work. Start with checking for fouled trigger points like Shooter suggests, move on to check injector firing etc. Most of the time dirty trigger points cause D-Jet issues (at least in my experience).

[Graham]

If the electronic ignition module is not hooked up and the car starts, it either has been converted a Pertronix point replacement, or perhaps has been converted to a conventional ignition.

There are engine manuals on-line - I have to run, but you can find them in W116 and R/C107 forums maybe here and on Benzworld.

Good Luck!

[meltedpanda]

by ICU do you mean the small silver box or the ECU under the passenger footwell. ICU's can be bypassed as Graham notes, ECU's cannot. I would start with Trigger points, ensure you are getting spark. I have a few ICU's lying about if you find you need one.
Other than that , research D JET and you will find a ton of info, check my SL forum posts , Graham and others , we have pretty much been through every issue with the DJet. It is not a complicted system once you learn the basics
Another very good resource it the Watson book on how to tune a BOSCH Fuel Injection system