Q: almost no acceleration when cold need very light touch on gas idles fine motor does seem to rev up without a load was told t

asked by on January 07, 2017

almost no acceleration when cold need to warm up for quite a while before driving also needs very light touch on gas pedal or car will just bog down I have replaced cap rotor and plugs but really is a fuel issue was told to try to replace eha valve but they aren't cheap would replace it if it was the problem

thanks tom

My car has 160000 miles.
My car has an automatic transmission.

Your car uses the KE injection system which is unique in that the electrical system can fail, and the injection system will still operate and keep the car running. Only problem is, you don’t have any fine fuel trim like cold start enrichment or acceleration enrichment. The fuel pump relay has two circuits, one powers up the fuel pump, and the other powers up the injection ECU. Sometimes the ECU part of the system goes dead, and the EHA isn’t even powered up, but the car still runs, though poorly. So any attempt to diagnose the problem needs to begin by verifying that the electronic portion of the system is working. The 1986 model can store codes which can be retrieved with a test light, but if the electronics are down, you won’t see any codes. If you can’t sort this thing out on your own, Contact Your Mechanic to have a technician come to your home or office to check out your Mercedes and let you know what it is going to take too fix it.

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