Throttle body sensor problem

Hello,

I have a 2000 W-reg K11. It's a 1 litre 16v, and doesn't have coils.

The other day it began jumping whilst driving, cutting out coming into traffic lights (but starts again immediately), and is running very rich, with a sooty tailpipe and a strong smell of exhaust fumes. It drives horribly and is essentially unusable.

I ran it to the garage I use, and they identified a sensor on the throttle body that has gone. It's the top sensor. The garage think the sensor cannot be replaced, and that the whole throttle body does. Is this correct? Does anybody have any advice? What is this sensor called please?

Kind regards.

The cheapest & simple DIY test is to unplug the MAF sensor & test drive the vehicle.

If the driveability significantly improves then the MAF is at fault.

It will throw a CEL but be drivable & we used ours for 18 months & even passed an MOT with MAF unplugged

Also read the corresponding links at the bottom of each MSC page.

Thanks Micra Paul.

I questioned the mechanic and he said "I can't leave it unplugged, because you won't have a throttle". But I'll try it this afternoon anyway, because he's the only person who has said this.

EDIT: I just unplugged the MAF and drove it down the road a bit, and the symptoms remain. In fact, at one point, they worsened for a few seconds and there wasn't much power for a hundred yards or so. Still an very rich smell of exhaust fumes. So the car is unusable with or without the MAF plugged in.

Quote: "Won't it be using more fuel than necessary though"?

Ans: Possibly?

Quote: "It drives horribly and is essentially unusable"

As you say that the vehicle is unusable ask the garage for a firm fixed written price to sort it?

In the meantime Maf (only one multi plug on the TB) unplugged it will be drivable.

Go for it.

Ah looks as if I edited my post at the same time you were replying to the unedited one.

Back to basics review of all the symptoms & issues

Inspect, test, assess

Quote: “cutting out coming into traffic lights (but starts again immediately), and is running very rich, with a sooty tailpipe and a strong smell”

Perhaps its not getting hot enough or the eng temp sensor is in error & its running with a cold enriched mix?

Perhaps. I'll have to pick up an OBD reader next week and see what that says. There's no yellow light on the dash, so I'm assuming (perhaps naively?) that there'd therefore be no codes?

Re reading your symptoms,

Quote: “it began jumping whilst driving, cutting out coming into traffic lights (but starts again immediately), and is running very rich, with a sooty tailpipe and a strong smell of exhaust fumes”.

Our micra began misfiring, erratic unstable engine throttle control & jumping kangaroo un driveable with no yellow CEL & no fault codes.

Unplugging the Maf calmed it down rendering it usable.

Are you sure you unplugged the correct multiplug, the upper of the two on the drivers side of the TB. The grey plug, & not the red one?

Yes, it was definitely the right plug. It didn't calm mine down to make it usable, unfortunately, but it changed the symptoms slightly.

Less kangaroo-ey, and didn't cut out when coming to a stop, but seemingly very limited in revs a few times, but had full revs at others. Also, still had very strong exhaust fumes. When plugged in, I had full throttle at all times.

Further research of well known TB issues with early K11 non coil pack series consists of a simple DIY repair to re solder the dry joints behind the cover plate on the side of the TB.

Search results for query: Solder Maf | Micra Sports Club

Nissan micra throttle body re-soldering guide - Cisco's Micra Files

Resoldering_CG13DE_ThrottleBody (micra.com.au)

A good read if your determined.