Micra K10 - Stalling when revved, fuel pump woes

[slunk]

Hi,
I recently bought a 1988 Micra K10 1ltr GSX. It's been great for the past few weeks apart from some worrying rattles and knocks from the suspension/wheel bearings...

However, a few days ago it all went tits up. I'd just left work, it was raining heavily and I was sitting at a busy roundabout waiting for the opportunity to join. A small gap appeared and I accelerated onto the roundabout but just as I got into the central lane there seemed to be a sudden cut in power, then power, then cut and so on so I was left 'jerking' across the roundabout - it wasn't misfiring, just intermittent total losses of power, much like fuel cuts. I jerked forward to the next exit and pulled onto the verge.

Ever since then, the engine has started and idled ok but doesn't like revving or any load. In neutral, if I bury the throttle the engine will gain a few revs and then stall - unless I let off immediately whereby it will return to idle ok. If I give it just a little throttle it will rev up slowly without stalling but as soon as its put in gear and the clutch is let out it will stall - no power all all!

So far I have checked and cleaned the dizzy, ht leads, plugs, all electrical connections with wd-40. Sprayed carb cleaner into the carb and changed the fuel filter. Listening to the carb it sounds quite spluttery.

I ordered a new fuel pump but went to fit it this afternoon and its the wrong type - it only has a fuel in and a fuel out whereas the one on the car has an additional line that seems to go from the top of the pump back to the fuel tank... Perhaps an overflow? Plus the flange on the new pump is about 10mm thinner than the old one meaning the studs are too long and it wont bolt down.

So what do people think? Why does this car have a different fuel pump to the ones everywhere sells for the 1ltr k10 micra? Does my carb splutter because the jets are blocked/broken or is the fuel pump is nackered? Is my spluttery carb causing problems or could it be something else? Timing perhaps?

Juts looking for some advice as I've never worked on an old school engine like this before.

Thanks,
Sam

 

[imp124]

the carb could do with a good clean out by taking the carb off and taking it to bits as a 20 year old carb can accumulate quite a lot of deposits in it even with the fuel filter, i would also check the fuel pump but if its idling ok i dont think there should be a problem, checking the vaccum hoses around the inlet manifold as well as these were all perished on mine and gave a similar problem. Would also check the timing etc as you have said.

let us know how you get on

Cheers

Steve

 

[K10 SHED]

Id check the timing + check the timing belt hasnt slipped a notch

you checked the dizzy connnections, rota arm, plug gaps etc

 

[BG101]

When mine did this it was because the ignition generator (inside the dizzy?) had gone, started after driving through a lake on a main road which you couldn't see until it was too late to slow down

Exactly the same symptoms, made it rather difficult to drive up hills and virtually impossible to drive onto a kerb so I could crawl under the car to try and see what was causing it. Cost about £150 to fix

It would sometimes run for a while so I managed to get it to the garage OK.

Check for absence of spark when the fault occurs. That will be a tell-tale sign.


BG

 

[slunk]

Thanks for the tips so far guys. I had a good look over it on Sunday.

The dizzy seems to be working ok, all the plugs are sparking with the engine turning over anyway.

Checked the timing and it doesn't look to have jumped a tooth. On that note, how the hell have other people removed the bracket that the engine mount bolts to opposite the cam pulley? There are three 14mm bolts securing the bracket to the head, the bottom one can be removed easily enough but the upper two are near enough impossible to reach! The plastics covering the cam pulley cannot be removed with the bracket in place.

Checked the vacuum hosing and there doesn't appear to be any leaks.

Collecting a new fuel pump tomorrow evening, will fit it straight away. Hope it sorts it! If not the carb will be coming off to be dissassembled on the kitchen table, the Mrs wont be happy!

 

[slunk]

Right. The new fuel pump didn't make any difference so after further fiddling I seem to have located the problem - faulty compensator valve inside airbox. It seems to be always open which is causing the engine to under fuel. I've read this valve is needed for hot conditions, is it necessary for the British climate? Would it be worth replacing or shall I just block it off?
Cheers

 

[ollyc98]

I blocked mine with no problems, just makes it run a bit rich when hot