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Discussion Starter #1
Hello all
I just bought a 190 2.0 1986.
At constant speed the car goes quite ok, but its hesitating when i accelerate if i apply to much throttle.

I also notice this when driving slowly in the low gears: the car is juddering very quick. Its like the engine has problems finding the correct fuel mixture and is just wandering around the correct point....

I am suspecting something with the carburettor, ignition/fuel acceleration advancer or fuel filter, but this engine is new for me. If someone could give me some tips please!

Rgds
Odd
 

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There is many things that can cause a vehicle to hesitate. First step get a shop manual to the car it will help you alot in testing parts on this vehicle.

Since you just got this vehicle it would be a good idea to tune it up anyway.

I would start with the basics Plugs(correct plug only no platinums) Distributor Cap, Distributor Rotor, Fuel Filter, Air Filter. You can check or replace each one.

On down the list for hesitation problems is

O2 Sensor bad

EHA

Air fuel mixture incorrect which can be related to an O2 sensor

coolant temperature sensor sending wrong signal / disconnected/ bad

dirty fuel system

I am sure I have missed some things but this is the biggest ones I can think of off the top of my head. Do some checking and testing and let us know
 

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I'd say the following:

Lean mixture
caused by: MAP sensor, TP or speed sensor,weak fuel pump, dirty fuel injectors, leaky fuel pressure regulator.

Vacuum leaks
Breather hose, leaky EGR if has one.

If accompanied with misfire:
Bad plugs and/or wires, wet plugs or bad coil
 

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I had occasional hesitating/stalling. Checked most of the usual suspects (ovp, fpr, vac hoses, fuel filter, etc) with no change. Switched to 98 RON fuel and symptoms 99% gone (1 stall immediately after refuelling) over 5 months. This might be a simple route to try.
 

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Discussion Starter #5
Thanks for replies.

This engine has a carburettor and no O2 sensor.

So i am not sure weather it has MAP sensor, TP sensor etc ?

Problem is that carburettor engines are too old for me.....
I only understand engines with never electronic systems.

Ok
So plugs and filters are up for a change, then maybe try 98 oktan.

rgds
Odd
 
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