Won’t start. W140 S500 1992

[locoroco]

Hi! So I am really in desperation right now. I had a problem when sometimes my car could just die on the traffic light, etc and had a bad rpms while on P. Now, it just won’t start and stalls after a brief idle with rpms going really low and unstable. Coming from the sound, it looks as if only 4 cylinders are working. Also, you can smell a strong odor of gasoline coming from exhaust. It works just fine on high rpms (if you hold a gas pedal). Spark plugs, wires to them, distributor caps are new. Yesterday, I cleaned contacts on ignition coils. Nothing changed. But the one moment that caught my attention was some additional copper wires attached to one of the contacts. Could thia be the problem, despite car working before? Will appreciate any help.

 

[mioba]

Those main electrical contacts are pee poor. Undo, wire brush refit and apply grease (vaseline).
Those loose wires are not standard and you should see what they feed - trace them.
May solve your issue as its a clear starting point.

Sounds like a vac leak tbf.

 

[Uncle Benz]

Some proper bodgery afoot there my friend. I can’t begin to diagnose your fault having seen that!

 

[locoroco]

Update: cleaned all the contacts once again, started it and the car works fine! I am really surprised. But I should remake it in a proper way soon

 

[locoroco]

Also that’s how most of the w140 would look in Ukraine, they have definitely seen better times. But it is what it is and I need to deal with all the “excellent” repairs the previous owner did in order to save some money

 

[mioba]

Good stuff OP. Learning by doing and doing it properly is most rewarding!

 

[alexanderfoti]

Love the brown velour! They are all leather here

 

[locoroco]

Thank you! Almost every Mercedes fan tells me that. I did not know that this interior was pretty rare when I had just bought the car. It is in quite decent condition in comparison to the overall condition of my car. Only the steering wheel has an ugly white line drawn with silicone around the airbag.

Love the brown velour! They are all leather here

 

[locoroco]

The car has over 350 000 km (217k miles) on the odometer between, that’s why I am surprised by it’s condition

 

[mioba]

W140 era of mercs last of the proper mercs - built to last!