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.

Engine is sputtering Inspection $94.99 - $114.99 Get a Quote

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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

What does the Airbag Readiness Light mean?
The Airbag Readiness Light gives you information about the function of the airbags in your vehicle. If something is wrong with the airbags, this light will indicate when there is a problem that needs to be addressed. Since airbags are...
How do I extend the seat belt length?
If your seat belt is not large enough for you, then you can extend it. The seat belt does not come with an extender, so you will need to order one. To do this, go to your dealer, and bring...
When turning on navigation system, radio comes on too
The navigation system and the radio do affect each other and use each other to work. When the navigation comes on it turns the radio on as well to provide volume for the voice directions. This is normal operation and...
Car shuts off, the engine runs in park
Hi! You may be experiencing an issue caused by the idle air control (https://www.yourmechanic.com/services/idle-control-valve-replacement), the fuel injector (https://www.yourmechanic.com/services/fuel-injector-replacement), or EGR valve (https://www.yourmechanic.com/services/exhaust-gas-recirculation-egr-valve-replacement). If the engine runs fine while driving down the road, but won't idle, then thats different than it...
My VDC light came on while driving
Your Sentra is equipped with a stability and traction control system called the Vehicle Dynamic Control (VDC). The VDC system is designed to provide better traction during slippery driving by reducing engine output. This reduces wheel spin and can help...
Intake manifold runner control stuck
The IMRC (Intake manifold runner control) (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-intake-manifold-runner-control) is a vacuum modulated solenoid that operates a butterfly valve in the intake manifold. The purpose is to optimize the air/fuel ratio for best fuel economy and drivability. Sometimes the code will refer...
What does check parking assist mean when I put it in reverse
In most cases this means the sensors need to be cleaned. Have all the rear bumper and front bumper sensors cleaned and then try system again. If problem persists then have a mechanic like one from YourMechanic test the park...
My car doesn't respond to the gas pedal like it should
Hello, thank you for writing in. The engine is likely sensing an issue and compensating for it. When you restart the vehicle, the component may be passing its start up tests, and the engine stops trying to outperform itself. Start...
Fuel pump not getting enough power
It sounds like you may have an electrical wiring problem. Typically, you should have 4 wires (2 with ground, one with power and one with switched power) that are working to complete the circuit. The ECM will connect one of...

Related articles

A Buyer’s Guide to the 2012 Mercedes-Benz ML350 BlueTec
The The 2012 Mercedes-Benz ML350 BlueTec is a safe vehicle that offers many standard features such as solid wood accents, thick leather on the seats, and memory buttons to save your seating position. The ride is comfortable as it has...
The Best Used Cars to Buy If You Live in a Windy Area
If If you live in a windy area, one of the most important things you’re going to be looking for in a used vehicle is the ability to remain stable on the road on even the most blustery days. That...
How to Source Parts For a Classic Mercedes-Benz
Classic Classic Mercedes-Benz cars are just as elegant and gorgeous as current model year Mercedes vehicles in many cases. There is a devout following dedicated to classic (https://www.yourmechanic.com/article/how-to-buy-restore-and-sell-a-vintage-car-by-jason-unrau) Mercedes vehicles who are passionate about the technology, styling, and responsive handling...