MAF Sensor again...

Seems to be a recurring theme on these forums.
Anyway, I've posted a couple of times before RE my faulty MAF sensor.
This is a facelift Micra with the Bosch TB - not the one that can be re-soldered.

The original MAF got so bad, I couldn't get past a few MPH - unplugged it for a short trip and everything went back to normal.

Bought a replacement MAF on ebay for ~£27. Not very good - poor MPG (mid 30's instead of previous mid 40's), hesitation, hesitation through the gears and poor high speed performance. Occasionally cuts out when the revs drop too low (turning off electrics and coming up to junctions). Has also given me the code P0100 (MAF circuit malfunction).

Got another MAF sent out from the same seller. This one fixes most of the above problems, but still with poor high speed performance and a new problem of kangarooing! Violently jerks under acceleration! Because of this I've reverted back to the first replacement sensor I received.

My questions:

1) Why would the Haynes manual say this sensor is not replaceable, and that you must replace the whole TB as a unit

2) I've been thinking of the possibility that it could be something else causing the problem, but I'm put against this idea because the car performs fine with a sensor unplugged, and each sensor I am trying has it's own characteristics - making it (to me) more likely to be the sensor itself at fault.

3) Do you have to reset anything when you replace the sensor. I've been scouring the Internet - some people believing you have to unplug the battery for about 24 hours, others saying it wouldn't make any difference...
I've just been swapping them out without following any of these supposed reset methods.

I must just be really unlucky with these replacement sensors I'm trying. It's so frustrating that Nissan or Bosch can't supply the genuine part - without the rest of the TB at a cost of about £450!!

Any advice / guidance / answers will be greatly appreciated!

Thanks!
 

frank

Club Member
i wonder it a maf or t/b from a different coilpack nissan would fit slug ? qg maybe (one of the reasons i like my ga16 t/b, no recurring problems with them eh)
 

Dave_Ally

Ex. Club Member
Whilst mine seems to have (finally) settled down (light has been off for a good 350 miles now) I too have noticed a decrease in MPG with this no name MAF, roughly about 200 miles to 25 litres which is about 36-37MPG. I have a feeling they're not made nearly as well as the originals, I wish they could be sourced from Bosch as it is just a replaceable part :doh:

As a side note how do you tell if your Bosch throttlebody is water cooled with pipes or without? Do you have to take it off to check?
 
Could I have one of these issues? I get around 300 miles for a full tank and I thought I would get more. Seems to make little difference if its mixed, distance or local driving either. Car has done 32k T reg. I re soldered the TB and changed all filters and plugs and oil etc. Maybe I was expecting more mpg from it and not being realistic:eek:

EDIT - Just worked it out and I am got around 36 mpg on the last tank which was 300 miles mixed driving, £47 which filled it was £1.27 L so its not so bad really, its just fuel is going up daily. Sorry to take it off topic.
 

Dave_Ally

Ex. Club Member
It depends waj as you will have the older Mikuni throttlebody, I think the rest of us in here have the last shape K11 with the Bosch throttlebody. Yeah fuel is on the up and up so I'm looking at ways of saving a few pennies to!
 
I think its actually doing ok really as its 12 years old and cost 800 quid so its all round cheap. Just a shame fuel is so pricey and it aint gonna come down only up:(
 

Seb_

Give me some frogs.
Site Supporter
Tomorrow after work I'm going to Mercedes, they are the only one to sell the CRC MAF cleaner in France.
My project is tol clean the MAF, the iddle valve, resolder the joints, and fit the N15 Almera airbox in a row, maybe this weekend. I will make a guide and take lot of pictures.
Cheers
Seb
 

Dave_Ally

Ex. Club Member
Did anyone get any further on with theirs? Whilst my light hasn't come back on I've made two trips today from cold and both times I've felt juddering when still cold and hesitation when accelerating. Think my cheap MAF might be on the way out, maybe my only solution is to get a new throttle body if you can't get the individual MAF :(
 

Dave_Ally

Ex. Club Member
Right, gonna go on a mixed drive and get some values from the MAF sensor and the O2 sensor tomorrow using OBDII. Don't suppose anyone would know roughly good values for the MAF to be reading at in g/s at idle, accelerating etc.? Any other things I should be looking at or any useful custom Nissan PIDs I could use? Any help appreciated :D
 

Dave_Ally

Ex. Club Member
Lucky :p

My long term fuel trim is at 21% right now, idles at 550-640 when warm. Maybe my throttle body is on the way out, gonna try a genuine Bosch front O2 sensor instead of whatever it was replaced with last time, worth one last shot before throttle body I guess.
 
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