Audi 80 B3 2.0 115HP Mechanical Injection: Starting Issues, Gas First, Fuel Pump, Flow Meter

Question

Hello. I have a problem with the Audi 80 B3 2.0 115KM. In order for the car to start, you need to start it on gas first and if it catches up (but will not start, only after a longer spin of the engine), switch to petrol. However, it will not start on gasoline, but must first get gas. The fuel...

helmud7543 · Answer

Flow meter and mechanical injection? Write the engine designation or give photos because I am not sure if there is any electronic control there. What is the LPG installation?

Krzysztof Kamienski · Answer

Yes, Bosch K - Jetronic. Same as Porsche 924. Check the automatic choke system - solenoid valve and bimetal.

bartekp5555 · Answer

Added after 6 [minutes]: Could it be the fault of the stepper motor?

Doktorr · Answer

There is no stepper motor here. Possible causes of starting problems are: too low fuel pressure, damaged or badly adjusted damper, damaged contact on the flap. Gas incorrectly fitted.

Anonymous · Answer

There is a central starting injector (blue body) on the manifold. Check that it gets power at the plug. Possible defective thermal switch if K-Jet. If KE, then the injector is supplied from the controller. If there is no power in the cold, you would have to check the coolant thermistor, the harness and the controller itself.

bartekp5555 · Answer

As such problems with starting, she does not just start immediately on gasoline, but at the beginning, when it is cold, turn on gas and if I get it, then switch to gasoline and go. The gas itself will not fire when it is cold. Are you sure there is no stepper motor, I think there is.

Krzysztof Kamienski · Answer

It seems wrong to you. I have a Porsche with this engine, luckily I didn't think to install LPG installations. So I know what and how it works there.

bartekp5555 · Answer

What is this marked in a red circle?

Wawrzyniec · Answer

Ordinary motor with a piston on the axis which moves depending on the angle of rotation of the motor and the return spring. The angle of rotation of the motor shaft depends on the applied voltage. I had the same in the same car, only with a 2l 16V 150KM engine on full, mechanical injection, also gassed. Except for the hatch locking up after each sneeze, it worked flawlessly.

Anonymous · Answer

It is true that there is no stepper motor because it has an idle speed valve but he is not the cause. It doesn't. Secondly, do not compare to the Porsche, apparently different engines. If I'm not mistaken, this is AAD, you have a lot to check from the ECU temperature sensor to the tightness of the intake, but I blame the fuel distributor for LPG This is called the flowmeter potentiometer or rather the flap position.

Anonymous · Answer

A picture to systematize the information posted here.
Just to be clear: The idle air valve is not a stepper motor. Well, in older KE it is simply a bimetal diaphragm, which is electrically heated, in newer ones it is a proportional solenoid valve. Has the dear author checked the operation of the starting injector? Without it, the cold engine will not start, because the fuel pressure regulated by the regulator on the distributor depending on the temperature does not allow for the starting dose to be given by the working injectors. You can even do an experiment quickly to supply the starter injector briefly with 12V and try to start it. The second important thing is to check whether the fuel pump relay turns on when turning the starter. It is activated only after impulses from the ignition system, so if it does not start the pump, it will not start on petrol. It is possible that the relay does not catch during the starter operation, and after firing on gas, it does.

Audi 80 B3 2.0 115HP Mechanical Injection: Starting Issues, Gas First, Fuel Pump, Flow Meter

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