I have been working on a 1987 190E four cylinder that has been sitting since 2002. I have spent a couple hours today reading through all the cold start write ups on this vehicle. I have gotten the car to where it will start/idle and run after it is hot but it will not start cold UNLESS I pour a little fuel into the fuel distributor and press the throttle at least 1/2 down while cranking over. If the engine is hot it will start/idle without touching the throttle. I put 12v on the cold start injector and can blow through it ever so slightly. Should I be able to get alot of flow through it? I put a volt meter on the connector coming to the cold start valve and it did not look like I was getting a signal to it during the start procedure. What controls this signal? Where is the thermostat for this loop? The OVP looks original and probably needs to be replaced. Just to get the car where it would run I had to replace the fuel pump. The fuel that came out of the car was nasty and I'm sure I have not run enough fuel through it for the Techron to do it's job. In addition to the fuel pump so far I have replaced the accumulator and fuel filter with good working "used" spare parts in addition to installing some new spark plugs to get rid of the platinum plugs. I have put fresh fuel in it with a couple bottle of Techron.

One other thing. The insulation on the wiring going to the cold start valve was bare and copper was touching copper. I separated these wires and taped it up. Could there be a fuse somewhere that popped when they touched? Obviously, I'm not working with a schematic here. I'm suspecting the remainder of the wiring harness has some issues too. It is brittle as all get out. I probably will split it open and try to re-tape it.

Any thoughts/comments are appreciated.
tia

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Jim

Well one of the may things that control that is the coolant temp sensor for the cis inj.. do a search for the test procedure. Its a very comon fault and the cheepest to fix.

I may even try another OVP relay. I know the car has had some jumper cable put on it prior to me getting it. Which sensor is the coolant temp sensor for this circuit?

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Jim

One other thing I remembered this morning. The SRS light stays on most of the time when the vehicle is underway.

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Jim

New OVP relay did the trick. Guess it just goest to show that a bad one will keep a cold car from starting. In researching on here about the cold start injector. It probably was not supposed to be operating anyway because it was always above 59dF when I was trying it.

mbshop comes through again because I found everything I needed to know to troubleshoot the car here using search and some time.

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Jim