Mercedes-Benz 420SEL Questions

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Start ok but then black smoke, no acceleration stalling

I have a 91 Mercedes 420 sel, am having issues with vehicle randomly surging while driving, almost like you lift off accelerator, if you push gas pedal, the fuel consumption gauge moves like you are flooring the gas, but the car doesn't respond, is ...

My battery keeps running down due to constant static coming from radio car doesn't need to be started nor does key need to be in the ignition and radio is able to be turned on is this normal? ????

The problem just started but I notice for a few years when I first accelerate, it would race while shifting, but I thought that was only normal. How can you help by offering a diagnosis.

I have replaced the climate control switches, a/c compressor, mono valve, thermostat, I need help and or cost for repairs

I know that the ezl module controls the advanceing and retarding of the ignition not able to adjust the timing

which rims are better alloy or chrome plated?

My light switch seems compromised. When I turn the switch the running lights do not work. My Brake lights work, the front right headlight works and my blinkers work as well. The front two lights only work when I switch on my brights. Is this a ground issue in the switch or just somewhere else in the vehicle? Also, none of my dash or gear selector lights work but the door lights work as well as the overhead cabin light. My fuses are all in check so I have no idea outside of my current knowledge. The vehicle as of now only has 152000 miles. Any insight would be greatly appreciated! Thank you for reading!

dashboard gauges not working

The economy needle has gone from black all the way to red.

what is the voltage supposed to be on the fuel pumps

The car is locked and also the trunk and front of the car. Even still the alarm goes of at random times when the car is locked. How can i fix this issue?

the car has not been cranked in 7 years I just bought it

When I am stopped at a traffic light. Oil pressure drops to number 2 and feels like cars gonna cut off. Also does a thumping noise and car vibrates. Put car in netural and it runs fine. Put it back in gear starts thumping noise. Drives normallay. Just at a stop does the thumb. Checked all fluids and everything is fine. This is the second time this has happened. Second time it started after I put gas in the car then it started the thumping and oil pressure needle jumbs up and down. When got to my desanation. Put car in park and runs like a champ. Dont understand whats wrong with it. Any ideas before I take it in?


as soon as the car run the abs ligth in the dash goes on. in reverse the car don't do that

This is the second set of injectors, 68k original car miles. How do I select new injectors that won't leak-down?

Note: At 1500rpm if the front injector fuel lines are broken loose air escapes and upon retightening the car runs smooth firing on all cylinders.

It looks like the clutch assembly failed, shifted, spewed oil, caught fire when grinding against a fitting. What do I need to concern myself with when replacing?

Can't get new relay to snap into the mating 10 pin assembly. Can't get the two notches on the relay inside the plastic holder.Do I need to remove the entire plastic holder (which houses 3 relays)? One of the 2 nuts securing the plastic holder to firewall has zero clearance! Help would be greatly appreciated.

my ABS light goes on and off, I just had new brakes and wheels mounted, could this caused a problem with ABS? advise---I found the ABS computer, removed and replaced. I am a senior without a lot of funds, however; I am trying to maintain my old gal, she just turned 100,000 miles, so she has to last me along time------please help

1986 Mercedes 420SEL. Have slight vibration coming from rear end.

Need to replace alternator belt