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Discussion Starter · #21 ·
Good Afternoon to All,
just got the ecu back from Germany. It got caught up in the DHL merry go round and was in transit limbo for almost 3 months. It arrived yesterday and I installed it this morning, now the car starts, stumbles at a low idle for a few seconds then stalls. Coolant temp sensor is in range, EHA resistance is in range. Idle switch should show continuity to ground but measures open at idle. Wide open throttle portion should show open but measures 89ohms. I disconnected the switch and grounded the idle switch portion but it does the same thing.
Going back over the diagrams.
I’ll update when I have something
 

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Discussion Starter · #25 ·
It works only with cold start injector?
It almost seems like that. However, the throttle switch input seems incorrect and when I measure the throttle position sensor on the side of the throttle body I have no continuity on any of the terminals.
 

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Discussion Starter · #26 ·
Can someone tell me what this unit is? What position should the "stem" be in? Extended or not
Automotive tire Hood Motor vehicle Trunk Automotive design
 

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Can someone tell me what this unit is? What position should the "stem" be in? Extended or not
It is fuel pump safety switch. In some manuals it is called "inertia switch" too. It will disable fuel pump in case of capsize of the car and, probably, there is mounted a overheating switch too. The button should be pushed down. I wrote about this thing in one of earlier posts in this thread.
 

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It almost seems like that. However, the throttle switch input seems incorrect and when I measure the throttle position sensor on the side of the throttle body I have no continuity on any of the terminals.
Looks like throttle position switch is a binary device with common positive voltage, sourced at "overvoltage relay" (this relay with fuse at its top) and two outputs. Outputs will not be shorted to the ground(!) but to this positive voltage(!).
 

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Discussion Starter · #29 ·
Thanks. I was relying on my previous mercedes and BMW experience with this system. What I have found so far is Pin 9 (earth connection) was poor. Had 4 volts on it as opposed to being less than 100mv (per my standard). I added another ground wire and now it reads less than 100mv.
It appears as if you are correct and it's only running on the cold start injector. The fuel pressure is good (new pump and I did confirm the pressure and flow).
Scratching my head at this point.
 

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Discussion Starter · #30 ·
Looks like throttle position switch is a binary device with common positive voltage, sourced at "overvoltage relay" (this relay with fuse at its top) and two outputs. Outputs will not be shorted to the ground(!) but to this positive voltage(!).
I was following the Bentley service procedure and the switch has an idle contact and wide open throttle contact. In each case when activated the intuitive resistance should be less than 1ohm
 

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Thanks. I was relying on my previous mercedes and BMW experience with this system. What I have found so far is Pin 9 (earth connection) was poor. Had 4 volts on it as opposed to being less than 100mv (per my standard). I added another ground wire and now it reads less than 100mv.
It appears as if you are correct and it's only running on the cold start injector. The fuel pressure is good (new pump and I did confirm the pressure and flow).
Scratching my head at this point.
Check twice. In diagram available for me, pin 9 (black-purple wire) is not for ground but for EZL resistor.
 

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Discussion Starter · #33 ·
This is the service procedure that seems to be somewhat accurate?
I do sincerely appreciate the input.
Plant Font Paper Document Symmetry
 

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I don't know. Just write what is at diagram in my hand. EZL is fitted only in cars with catalytic convener. Item (3).
Font Parallel Rectangle Pattern Diagram
 

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Discussion Starter · #36 ·
I don't know. Just write what is at diagram in my hand. EZL is fitted only in cars with catalytic convener.
Fair enough. In any event the car still starts then stalls pretty much immediately. Before I sent the motronic unit for testing/repair it had no spark from either ignition system.
 

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Discussion Starter · #37 ·
The car came to me originally for a no start and the fuel pump was seized. (It hasn't been driven much).
Does anyone know if there is a pump in the fuel tank on the Turbo R?
 

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Discussion Starter · #40 · (Edited)
A little more investigation this evening. I’m now certain that the engine is starting on the cold start injector and stalling pretty much immediately. I installed a jumper to keep the fuel pump running And no change. Just for fun I measured the current to The EHA, 100ma - Key on. Drops to 0ma - within 1/2 second do starting.
Im going to confirm fuel, control, and differential pressures tomorrow.
Im not looking forward to pulling the intake assembly should I need to check the movement of the airflow plate !!
Its been awhile since I worked on these systems but its coming back..a bit at a time.
As is typical with these vehicles, it has sat for long periods of time, just over 90,000km in 31 years, so who knows the internal condition of the fuel distributor.
 
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