Would be nice to have a bit more detail on the symptoms. Does the erratic ticker occur...

Hi folks,

Im a newbie here, so hello everyone.

My Boxster has an irratic tick-over sometimes, I have replaced my O2 lambda sensors, and all is good with them, can someone please let me know what the average MAF sensor readings should be.

I have a feeling my one may not be working as well as it should. I have diagnostic software, however I do not know what the average reading should be on tick-over and while driving. Any help would be appreciated, at least I could then be certain it is or isn't the MAF sensor.

Thanks in adnvance

Paul.

Quote
Paul-sussex uk
Hi folks,

Im a newbie here, so hello everyone.

My Boxster has an irratic tick-over sometimes, I have replaced my O2 lambda sensors, and all is good with them, can someone please let me know what the average MAF sensor readings should be.

I have a feeling my one may not be working as well as it should. I have diagnostic software, however I do not know what the average reading should be on tick-over and while driving. Any help would be appreciated, at least I could then be certain it is or isn't the MAF sensor.

Thanks in adnvance

Paul.

Only when teh engine is started from cold, warm, or hot, or varies?

Is the symptom a varying idle speed and what is the variation?

Based on the info you provided, the symptom doesn't sound like it comes from a bad MAF. (I want to say it sounds more like a VarioCam solenoid acting up but my 02 Boxster just had this problem so every erractic tickover is going to make me think VarioCam solenoid for a while...)

Anyhow, you can disconnect the MAF at the wiring harness and see if the symptom is still present.

Before you disconnect the MAF, while the symptom is precent, check the short term fuel trims, the engine load, ignition timing, and intake and coolant temperatures.

The one time my car's MAF was truely bad the short term fuel trims were banging around nearly rail to rail. In the meantime, the Air Flow Rate reading was based on my observations over time normal. I forget what the reading is. WAG is 0.45 to 0.55 g/s at hot idle.

I do not recall if the engine load was goofy but it should be around a couple of percent at hot idle with no heavy accessory loads (lights, A/C, etc.). Upon cold start you want to see the coolant and intake air temperatures about the same.

If one or the other or both are different from each other and from true ambient temperature the MAF which is responsible for the intake air temperature (IAT) or the engine coolant temperature (ECT) is acting up and the DME will not fuel the engine properly and erratic idle very likely.

Is the stock air cleaner in place and in good repair? Is the filter element intact?

Have you removed the throttle body and checked for signs of oil which is a sign/symptom the AOS is going bad, or has gone bad?

Sincerely,

MarcW.