Running with MAF unplugged, bad idea?

[KM666]

So collected my most recent bargin motor last night, a petrol Astra, on the way home it cut out at a petrol station and then would start but stall at idle, did this 4 or 5 times, eventually got it home and today did some service items on it.

So having started it and it running fine with new oil/oil filter, it then started cutting out and would stall at idle with the new air filter/plugs, so I sprayed a bit of contact cleaner on the MAF plug and accidentally left it unplugged.
It started fine and idled perfectly, with MAF plugged it it wont start without massive revs and even then wont start 9/10 times. MAF unplugged it runs fine. I've tried with both old filter and old plugs installed vs new, the one variable between it working and not is the MAF being unplugged.

So my question is this, what am I doing by having the MAF sensor unplugged? Other then the engine light being on.
I read somewhere that it will use a basic air feul mix based on throttle position, revs etc rather then basing it on the MAF, making most cars run slightly rich. Is there anything else it does?

[smartphone hater]

My diesel Astra G would go into limp mode with the maf disconnected.

[KM666]

I've heard thats what some do, but mine doesnt have any kind of rev limitations with it unplugged. Its all very strange.

[TheEnd]

It's pointing out that the ECU is getting the wrong data from the MAF for airflow.
It's likely to be a bad MAF, but at the same time, big airleaks can do the same, and it's only when the MAF is unplugged and the ECU will guess at the expected airflow that it'll work better.

[KM666]

TheEnd said:

It's pointing out that the ECU is getting the wrong data from the MAF for airflow.
It's likely to be a bad MAF, but at the same time, big airleaks can do the same, and it's only when the MAF is unplugged and the ECU will guess at the expected airflow that it'll work better.

Yeah the previous owner had trouble with it cutting out 2 weeks before selling but after I had initially viewed it, and now it doesnt start for me 9/10 times with the MAF plugged in. The previous owner sent the ECU off and it came back as working perfectly so its not the ECU. I'm working back from there, I cant see where it'd be leaing air, the vacume pipes are all in order as far as I can tell, It might benefit from a jubilee on the part of the intake I replaced. The MAF sensor is the only variable I can find between it starting and not.

[Nick1point9]

if it won't idle then it's likely there is an air leak.

[KM666]

So bought a new MAF sensor from vauxhall, fitted it, starts everytime on the button. Nice idle. Problem solved.

[v46m4n]

Had an Astra G diesel . with MAF connected it was gutless , disconnected, it had more power and better fuel economy! ran it for about 80,000 miles disconnected. no problems

[KM666]

[TheEnd]

I wonder if Renault like the splitter because they sell so many, or they think it was a bad idea as they need to always replace them.

[KM666]

Its the everso slightly lesser seen Espace version too.

I put these pics up to use the url for another site