Black smoke poor running

Hi Coen,

I want you to check that you have the right ECU and MAP sensor according to the lists in chapter 3 and 4. Please also measure all sensors on ECU connector after removing from ECU.

Somehow your switch from LPG to fuel and back must disable one of the two and let the car run on just the other system. There are various possibilities for that. Tell us please how it is done and how you ensure that LPG injection does not inject when car runs on fuel.

Trigger contacts do not make fuel mixture richer. When saying so I remember that 123 ignition showed a strange behaviour when I tested one for P1800 some years ago. It would create double trigger contact pulses. ECU would stull run properly as it would ignore 2nd impulse as obvious bouncing error. But noise on those lines could make the system do double pulses. I do not say that this happens in your case.

Hi Dr-DJet,

I will check if the ECU and MAP sensor are suitable according to the list in chapter 3 and 4. Then I will measurenall sensors after removing ECU.
Allso I will check the way the fuel/ lpg switches are executed.

I will be back with the information.

Regards Coen

Hi Norbert,

In fact I did. I was on my way when the LPG level ran low and switched to gasoline. The engineer stalled allmost immediately with black smoke and gasoline smell.
My Son had to tow me to the nearest gasstation (the shame). Luckely he used his Volvo 245 81’ so we did it in style.

But seriously. I have tried to run the engine on gasoline with the LPG hoses disconnected. It did not have any effect regarding the problem.

Regards Coen

Hi Norbert and Dr-DJet,

First thing to do this morning was checkking the motor temperature sensor. It’s located in a way it is hard to see. It turns out the cable was disconnected. After reconnecting te cable the engine did start and run properly.

Probably the cable came loose during replacing the alternator two weeks ago.

I like to thank you both for your effort to resolve the problem.

Regards Coen

Hi Coen,
thank you for the information.
The missing sensor leads to such effect only when the engine is warmed up. Starting cold wouldn't be a problem, but the engine would begin to emit black smoke after some kilometers and die.

I wish you all the best with your car.
Norbert

Hi Coen,

well that was an easy one. It is good to know that problem was solved.