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Cold Start Stumble...

996 Views 1 Reply 1 Participant Last post by  sam
Let's see if we can hit this subject one more time.

My '86 2.3 starts from Cold or Hot just fine. But when it's Cold, it really Stumbles and Misses. It Idles rough, but will stay at a good idle without stalling.

Aside from the rough, cold Idle, when you put the Pedal down, even just a bit, it begins to miss.

I took the Air Cleaner off and you can hear the Air Meter opening and gulping for air but it seems like I'm not gettng enough Fuel when it is Cold. When it fully warms up, it seems to run fine. Not a lot of Power but I think that this is due to a clogged Cat (which will be rectified soon with a good screwdriver poke).

I know that the Cold Start Injector is triggered by at least one of the Coolant Sensors, AND, my electric Fan runs all of the time, Hot/Cold, AC ON or OFF, so maybe the answer to this is that I've got (we've got) a defective Thermo Sensor somewhere that is:

1-Telling my Elec Fan to turn ON since the Engine "thinks" that it is Hot.

2-Telling the Cold-Start Injector not to pump more Fuel in because, again, the Engine "thinks" that is is already warmed up.


Sam ('86 190e 2.3 with some AMG Stuff)
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Addition to Post...

The Cold Start stumble sounds the same as if a Vac Hose is disconnected when the Engine is warm. I've sprayed both Carb Cleaner and Brake Cleaner on all of the Outside/Inside Vac Hoses in my attempt to locate a Leak somewhere, but I can't locate one.

Also, with the Engine running, but still Cold, I disconnected the Plug to the Cold Start Injector. No change. I had assumed that this Injector would be continually spraying Fuel into the Intake, while the Engine was Cold. I'll do a Voltage test on the Plug and see if there is any output.


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