matej2212

Oh okay, so I guess it is okay to show 1.5V when the throttle body plug isn't connected. So my problem probably lies somewhere else.

Ok, I'm really fed up with this. Problem came back. It gets better every time I change something, but returns after a few days. I tested the throttle body again with your (Ricardo's) guide, and found out that the voltages between pins 5-6 and 6-7 are around 1.5V, not 5V like you said they should be. I tested all the wiring and it's ok, so I guess I need a new ECU. Now I just want to ask if you are sure that the voltage between pins 5-6 and 6-7 should be 5V? I don't doubt your knowledge, just want to make sure. Since your picture says "Simos 2P engine management" I am adding the picture for magnetti marelli ecu. The throttle body diagram is the same, so I just followed your directions for your picture and then looked for the right pin numbers on my picture (so if you said voltage between 5-6 and 6-7 should be 5V, I checked voltage between 5-4 and 4-8 according to my picture which is for magnetti marelli ecu)

Ok, its definitely an ignition issue. I had an aftermarket distributor cap on the car, now I put on the old original (bosch) distributor cap and the car doesnt hesitate anymore. So I guess the aftermarket cap was somehow crap. But the bosch one still gets dirty after cleaning and driving a couple of minutes. Well I'll try to change the spark plugs and wires because they have never been changed anyway and then leave it. At least until the next problem appears.😅 Thanks!

Also the same symptoms were present the first time the coil was bad (although the car wasnt jerking as much). But it would be strange if the coil only lasted 10.000 kilometres.

Ok, thanks for your effort. Is there a way to test or to rule out the ignition issue first? Because I dont have a fuel pressure gauge and it would be easier to diagnose as much as I can myself, before taking it to a mechanic. I also noticed that the distributor cap contacts become dirty (they have grey/black residue which I have to sand down) after couple minutes of driving, is that normal or does it indicate something?

Here it is. I hope it helps, beacuse it is a little hard to see because I dont have a tachometer. But you can hear and see the car jerking and hesitating.

Checked the wiring again, replaced the number 1 fuel injector but the stuttering remains, the car still stutters when pressing more than 1/3 on gas pedal. What else could be wrong or what else should I check?

Okay, stupid question. Which cylinder is number 1?😅

I already tested the wiring before and I also tested the injector resistance which was 15 ohms, so I thought it is OK. Can the injector still trip a code if its resistance is OK?

No new codes, only the 01249 "fuel injector for cylinder 1 open or short to ground" that was present before.

Tried it but it didn't help. Even reset the throttle body but with no success.

Idling problem fixed! Changed the MAP sensor and the problem didnt come back! But another problem appeared🤦‍♂️the car accelerates fine if I accelerate slowly, but if I floor it at any rpm it starts stuttering or kangarooing. Seems like a problem with fuel or spark. Spark plugs seem fine, i checked resistance of spark plug wires and it is within spec and the coil was replaced couple of thousand kilometres ago (i hope it didnt go bad so soon). What should I check first or what are the most common causes?

Ok, I smoked checked the intake (with a cigarette) and there were no obvious leaks that I could spot. Is it normal then that the sensor is a little bit shiny? When i clean it, it doesnt look shiny, but after one ride it does. I guess that could be just remaining oil droplets which accumulated on the inner side of the intake? I will try to replace the sensor either way and report back.

Thanks, I appreciate your effort because I know I am probably getting on your nerves already, but I really cant find the problem. I will try a smoke test and see if anything stands out. I also checked distributor cap and rotor and they were dirty, I cleaned them, and after one ride they were dirty again (grey marks which were difficult to remove). Can this also cause the stalling when pressing the clutch and rpms going up and down?

I took it to a mechanic which said that MAP sensor is probably "too slow" so the idle goes up and down and the car stalls when pressing the clutch at low revs. I ordered a new sensor but I want to know how can oil be getting on the MAP since i've been running the car with breather hose disconnected and intake hole plugged. I know you said it isn't a problem from looking at my picture, but I just dont want the oil to faul my new MAP.

Yeah, i know there are two potentiometers. The resistance of the first one is from 1400 (closed) -730(open throttle), the other one goes from 730 to 1400 (the other way around). I don't know where autodata got this, but in "components testing" section for felicia 1.6 it says that it should be 1500-1600 ohms when throttle is closed. I guess that is correct because I don't know why would vagcom show 20 degrees when idling, when it should be from 1 to 7 (according to vagcom). That would probably also explain throttle body whine (computer thinks that the flap is at 20 degrees and tries to close the flap more, even if its in corect position and the motor whines).

I tried cleaning it but with no effect. The resistance is still 1400 ohms when closed and throttle angle is still 20 degrees in idle when it should be 1-7. So I guess its a new throttle body then.

Well I study electrical engineering and it sounds logical to me that if you clean a potentiometer it makes a better contact and resistance should decrease. So if my resistance at closed throttle is 1400 and it should be 1500 ohms I thought that clenaning it would make it worse or wont help. I don't know, correct me if I am wrong🤷‍♂️

I will try it and report back, thanks. Sorry I am not as perfect and smart as you are.

I doubt cleaning the potentiometer would help, cleaning it will probably decrease the resistance even more.

The resistance between pin 5 and 7 should be 700-900 when the throttle is fully opened and 1500-1600 ohms when the throttle is closed according to Autodata. But my rhrottle body resistance is 1400 ohms when closed. Vagcom shows 17 degrees of throttle angle when in idle but it should be around 1-7 degrees. So is that my problem?

I have a 1997 felicia 1.6 which idles roughly and almost dies when i press the clutch at lower rpms. I had a 01249 code for fuel injector 1 open or short to ground. My temp gauge wasnt working so I thought that code is because the engine is running rich because of faulty coolant temperature sensor. So i replaced the CTS and now the gauge works and stays in the middle. I also cleared the code and cleaned and reset the throttle body with vag com. The problem with rough idling and stalling came back after around 15 kilometres. I also looked if the computer is receiving the right temperature value from CTS and noticed that in vag com the air intake temp was actually showing the coolant temp and the coolant temp was showing 27 degrees which i think is air intake temp probably (you can see in attached photo that the values are switched). The car was warm and the screenshot was taken while driving so thats why the rpms are on 2000. How is it possible that the values are switched or is that normal? Also when I have the ignition on with engine off, there is a whining noise coming from the throttle body. The gas pedal cable has freeplay so that isnt the problem. Is it posibble that the throttle body is also faulty? The car otherwise runs fine. Sorry for the long post and thanks for the help!