Volvo V40 1.8 96r - Engine Power Loss & Misfiring on Cylinders: Ignition Coils, Candles, Injectors

Hello
A friend brought me a Volvo V40 1.8 petrol / lpg 96r. The engine has no power, it tugs. After removing (no matter whether the cap from the candle, or the power of the injector, whether gas or LPG) from the third cylinder there is no change. From the first and last car immediately starts to jerk more and goes out. After removing from the second cylinder a little goose works but does not go out. I would add that the car was at a few mechanics, and ignition coils, candles, cables, injectors and engine driver were replaced. Of course, all without changes. Typically, the car does not work on the third cylinder, or gently in the second there are also some disorders. It was connected to the computer, no faults came up. Cylinder pressure, 13 bar each. We accidentally started moving the hoses from underpressure (there are a lot of them) the car sometimes started to work as it should. And now like this:




If I unplug this entire black lower cube (I think it's a vacuum valve, there are two vacuum hoses attached to it) there are no changes in the engine's operation.
If I unfasten this cube with green plastic there are also two vacuum hoses attached, the car goes out immediately.

What is the first one (valve) for which after disconnection there are no changes in the engine's operation? is it possible that because of him these are problems with the engine?

How do I find out which vacuum device is inefficient and through which the car fails?

As for me, this is not a valve but a pressure sensor in the intake manifold.
Unless you're talking about something other than the black rectangle with the green plug.
If you disconnect the hose that goes from the collector, the engine should have a lower speed because it will be flooded. If you disconnect the plug from it, it will rather go out.
Since you disconnect the hose and nothing changes, it is possible that the sensor is damaged, which, for example, floods the engine and this does not work on one cylinder so that it would rather come out on the computer because an error should appear because the ECU will not match the pressure in the manifold relative to the throttle opening and there should be a rich mix error.
The sensor can be checked in measuring blocks on a computer or by a voltmeter.

If there is something else connected then give better pictures and show where it is exactly connected - one tube or two and where they are connected.

The sensor is the one with the green plug ?? because I found another sensor on the air intake, I don't know what it is, maybe the air temperature ?? this one like on the elbow ?? after disconnecting the plug from this sensor, there is no change on the elbow.



PS. A new problem, I put the key in the ignition to this Volva and do not want to turn, as if it would lock the ignition, no jerking the steering wheel does nothing, I puffed the WD40 ignition switch too, now I can't even start this car; /

Yes with green.
This photo is apparently a thermistor because it has two wires so I would say that it is a suction air temperature sensor.
As for the ignition, it is dismantled and the "key driver" will fix the ignition.
You don't need this one too much to start the engine. remove the ignition block and turn it with a screwdriver to the ignition position and then to the start position.

OK thank you, I will write something more on Saturday, because I called a car 60 km from me, they have a ignition there for PLN 70 and a vacuum sensor for PLN 35. On Friday I will go there I will buy it and on Saturday I will let you know on the forum. (Will I have to remove the steering wheel to dismantle the ignition switch, or will the plastic around it be unscrewed?). And I still have one question out of curiosity. Because we've determined that this green plug is a vacuum sensor. And the one at the bottom left of the vacuum sensor black plug horizontally positioned in this picture what is it for? are there also two hoses from the vacuum reaching?

I wrote that the photo is of poor quality and cannot be seen clearly.
What are these hoses connected to?

The first is how the MAP sensor from Opel looks

Similar from the bottom despite (in my way) coming on 1 hose?
Second intake air temperature sensor MAT, IAT.

autoManiak1 wrote:

If I unplug this entire black lower cube (I think it's a vacuum valve, there are two vacuum hoses attached to it) there are no changes in the engine's operation.

The valve can cause engine error, maybe the vacuum EGR, maybe the fuel vapor vent valve, for me it is also from the variable length of the inlet channels in the VGIS intake manifold. It works when the engine computer wishes, also the plug and one of the hoses may not respond.
If you have a reaction to vacuum hoses, then look carefully at whether they are not ragged, cracked, cut - they are not full of holes.
When starting off, watch if you move the hoses, but you do not move the electrical system.

Well, unfortunately it is not a vacuum sensor, today I changed it and in total a bit better on gasoline but after a while it started to jerk, lpg straight away.

Added after 2 [minutes]:

I noticed that now as I disconnect the wire from the vacuum sensor, as if the rotation was even, but on lpg it starts working unevenly

Hmm, did you manage to fix it?

The problem was with the electrical harness

Hello. I have the same problem. The same engine, only S40. Share the secrets of where to look for a problem with the beam. P.S. Last year, there were cases when I drove into a larger puddle at e.g. 40 km, and the same thing happened that I now experience every day 🤣 coughing, choking, lack of power. Then after a while it went away on its own or when I switched to bp and overgassed it a bit. Help

We installed the entire used harness; we did not diagnose exactly where the problem was in the old one.

Hello. You wrote that you replaced the entire harness, but only under the hood, or did the harness go from one thing to another? I have the same problem in my Volvo. I replaced the plugs, coils, injectors, injector rail, fuel pressure reducer, lambda probe and still the same. I read your post and now I`m thinking about the electrics, could this be why this suddenly started happening in my car?