MAF causing idle stall

I should add when I changed MAF and reset ECU and adjusted IDC again one time the car worked fine and I went one trip then few days later went to car and problem was same as before. Repeated everything I did before which didn't help then tried lots of new things.

Hi,

This vehicle isn't offered in the US, so my technical information is very limited. However, I will try to help.

First, have you checked for engine vacuum leaks on other engine components? For example, is the PCV good, the EGR not stuck, any damaged or disconnected hoses?

Take a look through these two links. The first one explains the most common causes of this condition. The second explains how to locate and repair an engine vacuum leak.

https://www.2carpros.com/articles/stall-at-idle

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let me know. Also, let me know if there are any present trouble codes and if you have a live data scanner. If you do, let me know what the short term fuel trims when at operating temp.

Joe

Thank you! I will take a look tomorrow at the PCV though I can't find replacement online. The vacuum pipe on the EGR was too difficult to tighten due to its positioning (PCV also happened to be in the way) I might need to fiddle with that again. Unfortunately this car doesn't have OBDii.
I will double check pipes and update here. thank you very much for your time.

Hi,

Let me know what you find. I have a feeling it may be related to a leak. Let me know if you have questions or need help.

Take care,
Joe

I've cleaned some pipes but there's no obvious leak. It's not easy for me to check some vacuum pipes behind EGR or the PCV.
Is it true you can check PCV is working by taking the oil cap off and put on while running there should be a suction force?
Problem is I can't idle to test things like that. I don't want to keep buying parts and not making a difference almost everything has been changed now. :'(

surely if car works with MAF disconnected then its not PCV or vacuum leak somewhere else?
Also the car lasts a few seconds from sitting for a day cold whereas from hot engine start it stalls almost immediately so temperature is affecting something.

When you disconnect the MAF, the computer recognizes the open circuit and runs at predetermined perimeters. If you wouldn't have told me the MAF was already replaced, I would have told you it is most likely the cause.

Are there any diagnostic trouble codes stored in the car's computer. I realize you indicated it doesn't have an OBD2 system. It should have something to retrieve codes.

As far as removing the oil cap, that isn't reliable. Without codes this becomes a test, evaluate, and then determine what needs done. I'm not familiar with this vehicle, but things such as a vacuum leak (as mentioned), engine coolant temp sensor, fuel pressure, idle air control, and so on can cause idle issues.

So, where do we go with this. I guess since the symptoms are indicative to a mass air flow sensor, we need to recheck that component. Since it runs with it disconnected, either it is bad or there is unmetered air getting into the engine. So, I will try my best to explain how to check the MAF. Please understand this is general in nature. I am not familiar with this vehicle.

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1) Turn the ignition off

2) Connect the MAF sensor’s connector.

3) Backprobe the sensor’s signal power wire with a multi meter, and the ground.

4) Secure the vehicle on a flat surface and in park with the parking brake engaged.

5) Start the engine. Have a helper keep it running.

6) Voltage should be aprox 0.5 to 0.7 volts.

7) Tap the MAF sensor lightly while watching the voltage

8) Voltage should remain steady.

9) If the voltage becomes erratic, chances are something is loose in the sensor and needs replaced.

10) Have a helper rev the engine to aprox 2500 RPMs

11) Watch the voltage. It should increase to aprox 1.5 - 3.0

12) If there’s no output response from the sensor, it is most likely bad.

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Let me know if this is something you can do at home or if you have other questions.

Joe

Hello,

I played around with the MAF and cleaned it again. I also changed spark plugs they were really bad. I also did the coolant that was completely sludge though I don't have a way to drain properly. Anyway the spark plugs helped now it behaves differently.
Now the issue is the engine is jumpy and the exhaust is puffing. I can drive the car and as it gets hot when I rev I get white smoke. I know the oil is too high as well but since the car is perfect with MAF disconnected its still something going on there.
So now sometimes it doesn't start if so I give it a few tries and then it does start but engine is shaking and exhaust is puffing at idle. With MAF disconnected car is fine. It's probably some vacuum issue but I think now I will take to garage since I can run the car with no dash warnings.

Hi,

The white smoke has me a bit concerned. Although the oil may be over full, it would burn blue in color. White smoke usually indicates engine coolant is getting burned in the combustion chamber. Not always, that is a head gasket related issue. If you want, here is a link that explains how to test for a head gasket issue. Most of it is visual. Take a look through it and see if it helps.

https://www.2carpros.com/articles/head-gasket-blown-test

Let me know what you find.

Joe

I'm only getting white smoke with MAF connected/not in limp home mode.
I can't find any leaks, my air filter is really filthy so I'm waiting for new one to arrive and maybe spray MAF again when that arrives.

If the filter is really plugged, that could be the problem. Let me know if it takes care of the problem. However, if you want to test it, simply remove the air filter to see if it changes things.

I have asked for another MAF to be sent by seller since behaves differently to original MAF which is worse. If I have time I might also manually wire/connect MAF to harness so that I can probe with multi-meter for shorts and voltage.

That sounds like a good plan. Honestly, you may want to request a different brand part at this point.

Let me know.
Joe

Hello I finally fixed the car! I'm so happy but also so annoyed because it turned out the MAF I bought stopped working and the second new one I bought which is higher quality works beautifully. hopefully this doesn't stop working soon too though!

Excellent! I'm glad that took care of it for you. I have to be honest. I see people getting inexpensive parts from online. They never seem to work properly or like in you case, they don't last. I don't know if you got it online or not. However, it like they always say. One gets what he pays for. LOL

You take care and if you ever have questions in the future, please feel free to come back.

Joe