Skip the auto shop - Our mechanics make house calls

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

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. 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

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: i cut off the roof

If you still have the windshield and install a roll bar then you should not have a problem, but if I were you I would check with local ordnance to make sure it is legal.

Q: My car won't rev or accelerate

Hello there. If you press down on your accelerator pedal and the engine will not rev at all, this is typically the indication of a damaged throttle linkage or throttle body component. On an older Mercedes-Benz, the throttle is not...

Q: Went out to start my 2001 E 320 turned the key and there was a loud snapping noise like a short circuit. Now the instruments stil

Hi there. It's actually a problem with vehicles over 10 to 15 years of age in general. What typically occurs is that the ignition relay will be come damaged after years of continual wear and tear. This is most likely...

Related articles

How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...