still beating on my 1986 560 ces with the cold start problem
no cold start injector signal
my problem seems to be no voltage at the coolent sensor

I have checked the wiring from the cis-e to the sensor I have replaced the cis-e control unit still no reference voltage to the sensor
with out the reference voltage there is no signal output to the fuelpump relay to engage the internal relay for the cold start
is there something other than a bad cis-e controler that can drop the voltage off?

The cold start injector only gets a signal during starter operation with the ambient temp below 58F.
Don't know where you live, but most likely it just isn't cold enough for cold start injector operation.

The signal to the EHA does 90-95% of the enrichment for cold starting.

If you disconnect the red/green wire to the coolant temp sensor & then operate the starter you should have that signal to the cold start injector.

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yes it is cold enough here in NC mountains to need cold start
and no I do not have the reference voltage on the wire going to the coolant sensor from the ecu
with out this voltage the starter imput is there at the fuelpump relay but no cold start signal from the relay to the injector
I replaced the ecu and it worked for 2 months and now Im back to no voltage at coolant sensor and no cold start action

Very helpful information for my issues I am suffering on my '91 560 of very difficult cold starts. I had no clue the EHA was the enrichment device when the CSV was not used.

Any ideas if the 86-91 560SEL all used the same CIS-E computer?

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I'm not a doctor, but I'll have a look.

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