Loss of power and struggling up hill

[Chellis]

Hi all,

Looking for a bit of advice, I've got a 2002 K11 1.0 with 65k miles on the clock, ran perfectly until September time when it seemed to lose power, it would struggle to get up to 50-55mph and going up steep hills is 20mph flat out in second gear. It sat SORN till last week when I got it MOT'd and have been trying to sort it out since.

I've given it a new air filter, oil+filter, new fuel filter, new spark plugs + ignition coils. Didn't expect it to change much but they needed doing. There's no engine light, no codes.

Having a read around it seemed like it could be the MAF sensor so I unplugged it and noticed no difference whatsoever, decided to buy a cheap one off of ebay for £25 and put it in today, the car was struggling to idle and stalling every time you put the clutch down. When I tried accelerating it would yoyo all over the place and I had to come off the pedal and put my foot back on to get it to accelerate again.

Decided that didn't seem right, unplugged the battery for 20 mins and then let it idle for a few minutes but no change (no idea if that would help but thought I'd try) so I've switched back to the old MAF for now (not that it seems to do anything).

I took the rocker cover off today as well while I was at it to check the timing chain, that seems fine no play in it at all, was going to try loosening the cat and see if that helped but got a round bolt I can't get off at the moment on the heat shield so couldn't try that.

Any advice appreciated, I'm wondering if I should get a brand new MAF from somewhere more reputable or try a second hand throttle body or something?

Thanks!

 

[.Maarten]

Aftermarket mafs are ****. Id test the o2 sensor and the maf and swap the maf with a known working one to test.

 

[jaycey001]

Sounds like classic throttle body to me, I had the same on a previous Micra, after changing throttle body with a second hand one it worked perfectly. I maybe wrong but I think coolant temp sensor can also cause similar problems but more likely throttle body.

 

[Chellis]

Thanks for the replies, yeah only got myself to blame for thinking a cheap one would work.. Managed to find a second hand supposedly fully working throttle body on ebay so will wait for that to arrive and give it a try then go from there.

 

[Chellis]

Ok so replaced the throttle body with a second hand one and no difference, got an obd2 scanner and an app and it seems like both old and new MAFs are at least giving a reading. Coolant temp seems fine and fan comes on when needed.

My o2 sensor graph looks fairly off and the fuel trim seems off with fuel trim bank 1 long term % at a constant -100.78125, fuel trim bank 1 short term % sits generally between -10 and +5 but occasionally dips to -100.78125 too. I'm guessing the o2 sensor is bad?

 

[5949403030495959]

Possibly, but another shot in the dark if I may, you are sure it's not just bad petrol?

 

[fuzzy-hair-man]

It looks to be trying to pull out fuel, I don't know how o2 sensors fail, but out might also be a faulty fuel injector or possibly fuel pressure regulator?

 

[Chellis]

I've put a new tank of fuel in and doesn't seem any different so sadly don't think it's that. I'd already ordered a new fuel pump so I'll change that and have a look at the injectors and regulator. I'll keep going don't want to give up on it just yet as I think (hope) the engine is fine still.

 

[frank]

have you checked the lambda output when pulling up a hill chellis ?
should be a constant .9v ideally

Coilpack Cold Start Enrichment

Is there a way to disable this on the C/P engines? or at least cut down the time it is on for, as i have noticed when cold and at 1/2 to 3/4 throttle i get a pulse in acceleration, it only happens when cold and every now and then, but it will happen when cold, without fail. It dont really...

www.micra.org.uk

 

[Chellis]

have you checked the lambda output when pulling up a hill chellis ?
should be a constant .9v ideally

Coilpack Cold Start Enrichment

Is there a way to disable this on the C/P engines? or at least cut down the time it is on for, as i have noticed when cold and at 1/2 to 3/4 throttle i get a pulse in acceleration, it only happens when cold and every now and then, but it will happen when cold, without fail. It dont really...

www.micra.org.uk

I only get readings from my scanner every few seconds but just took it up a hill to check the sensor, it started at 0.8 and decreased to 0.6 I was flat out in second slowly crawling from 20-25mph. My MAF sensor was hitting 25 g/s max and the car wouldn't go above about 3500 revs.

 

[frank]

those readings sound ok to me
i would be looking at the live timing advance next
then maybe a blocked exhaust ?

 

[Chellis]

Thanks for the advice, my timing advance when I recorded it before went between 3 and 32, 32 when going up the same hill I just went up. I'll see if I can remove the rounded bolt holding the heat shield on in a bit so I can loosen the cat and see if that helps.

 

[frank]

the timing on my dizzy type k11,s were 15 deg at idle, up to 50 deg at light cruise, and about 20 deg on a hard pull

 

[Chellis]

Thanks, still learning about all this stuff, I'll sort out checking the exhaust in the morning and go from there. Really hoping that is it, gets a bit frustrating after a while!

 

[Chellis]

I disconnected the exhaust after the cat and it seemed to run a lot better (sorry neighbours) managed to easily get up to 70 on the A12 and going up hill it wasn't struggling at all. Guess I'll get it up and have a look underneath see what's going on.

 

[welshdave]

maybe a bit late in the day - had a similar issue with my K12 and I found that there was a bad earth on the rear lights which everytime I tuned on the indicator and accelerated above 200revs I had kangeroo petrol. Cleaned up the connector all ok

 

[MicraMikey]

I disconnected the exhaust after the cat and it seemed to run a lot better (sorry neighbours) managed to easily get up to 70 on the A12 and going up hill it wasn't struggling at all. Guess I'll get it up and have a look underneath see what's going on.

Replying to a comment from 3 years ago but did you ever find out what the issue was? My 2002 K11 1.0 auto with 50k on the clock has recently started doing the same thing (loss of power uphill and on occasion very slow acceleration compared to what it was like before). Changed air filter, engine oil, fuel filter, spark plugs, run a some cataclean through it and still the same.

 

[dodginess]

Replying to a comment from 3 years ago but did you ever find out what the issue was? My 2002 K11 1.0 auto with 50k on the clock has recently started doing the same thing (loss of power uphill and on occasion very slow acceleration compared to what it was like before). Changed air filter, engine oil, fuel filter, spark plugs, run a some cataclean through it and still the same.

I have the same problem but with a 2002 K11 1.0 manual with nearly 80k. I've owned it for just over a year and on at least 3 occasions there was almost no acceleration when the car was under any kind of load, and even on a flat, straight road I couldn't get the car above 40mph. Then, the problem cleared itself after a few minutes. The engine runs fine at all other times, no kangarooing or unexpected loss of power. I saw an article on another web site that suggested a slipping clutch can also cause the same problem, is that possible? I've had two other K11s and this last car has been the hardest to drive in terms of gearbox feeling very notchy and vague and the clutch a bit off. When I recently took my car in for its MOT and explained the problem the mechanic suggested that the brakes might have been binding, although if it had been that I would have expected the problem to occur more often. As it happened again today while I was out on a short run I had thought about replacing the spark plugs and buying an injector cleaner, but as the problem is intermittent I'm not confident that it will fix the problem. Just to add, the revs were very low while this was happening so presumably not a clutch issue. I do have some MAF sensor spray handy but haven't tried it as I'm not sure where the sensor is yet. Based on some other posts I've been looking at, dirty/worn throttle body or lambda sensor are other possibilities.

 

[MicraMikey]

Replying to a comment from 3 years ago but did you ever find out what the issue was? My 2002 K11 1.0 auto with 50k on the clock has recently started doing the same thing (loss of power uphill and on occasion very slow acceleration compared to what it was like before). Changed air filter, engine oil, fuel filter, spark plugs, run a some cataclean through it and still the same.

Managed to diagnose the issue with my Micra by way of a loud pop and a puff of smoke in the mirror as I was accelerating uphill. Turns out the exhaust was blocked by the synthetic fibre (looks like a wig) that they put in the back box silencer of the exhaust to assist with sound muffling. The pop was basically the fumes ripping the back box silencer apart at the seam. The exhaust sound is much louder now, understandably, but it seems to have solved the lack of acceleration and power issue. Ordered an exhaust silencer off eBay for £37 so will get someone to fit it for me.

 

[dodginess]

Not the answer I was expecting, but good that it's sorted! Just to add to my earlier comments, my car feels like it's going into limp mode but without the check engine light showing which would tally with the revs being kept low. I will take a look at the silencer though to rule out something obvious.