Jimny losing power and cutting out with warning lights

Well lads, new member here... I recently bought a 2002 Jimny and am having a small issue.A few times now when driving, it starts to lose power, and the engine warning light and the immobiliser light starts flashing. The rev counter seems to be going wild too. When I turn it off, leave it for a min or two and turn it back on it's a little bit slow to start but then gets going again.It happened twice on the motorway and once going up a hill. I think it happens mostly around the 3000rpm mark too.Has anyone seen this before or know what it might be? Any info would be greatly appreciated.Cheers.

The usual cause is the crankshaft position sensor hidden between the alternator and the block.

The lights flash and the rev counter drops because it thinks the engine is stopped when the signal disappears. There won't be an error code though as it thinks the engine just stalled.

Thanks for your reply.

Would this also explain the immobiliser light flashing on do you think?? I have a sensor on order so will replace it early in the week.

Some people on a Facebook page mentioned about an earth strap, an ecu being damaged or a blocked cat!

Lack of power is often a blocked catalyst, but the rev counter dropping means the engine is stopping.

May actually be a bad earth, fractured cable or another fault like a coilpack breaking down (a missfire would set a fault code though), but the M series go through crank sensors like an elephant goes though sticky buns, they are cheaper than a diagnostic, and easy to change so worth a punt ( as the first shot of the parts cannon )

I had a similar experience with a Vectra 25 years ago,, sudden loss of power most dashboards lights flashed, speedo and rev counter went erratic, full scale, down to zero, repeat, then the engine died.

I coasted to a lay-by on a busy road and lifted the bonnet, the unmistakable smell of burnt wiring. It was a lease car so I was just getting ready to call the break down when this bloke stopped, said ‘they all do this’ and before I could stop him, he reached in and pulled a wire out of the harness, then said it would be fine and left.

The car did start and run ok, so took to the garage. I never saw the bill, but think they replaced some of the wiring harness in the engine bay.

Hopefully it will be your sensor, but when I read your post I thought if it isn’t the sensor, it might well be an earth or wiring. Mice are known to chew through the insulation and you get a variety of weird electrical problems.

Robin

Thanks again for your reply and info.

I put in two new ignition coils the other day. I will get the new sensor in this week and hopefully that solves the problem! Will keep you updated absolutely worth the punt.

Cheers

Glad you got it sorted! The funny thing is this has happened a number of times. And always after pulling in, turning off the ignition and restarting it comes back to life (though slightly longer to start than normal). Never smelled anything burning either.

I'll try the sensor first and see from there.

Many thanks for the comment much appreciated

It's a familiar story, and almost always the crank sensor. I've picked up some very cheap Suzuki's over the years with the same "untraceable engine fault".

Hello, I have the exact same problem. I changed the crank sensor that in front of the engine. Behind the fan if i remember correctly. This did not help. If i understand this thread correctly then I tried to change the wrong sensor? Right now i al not taking the jimny on the highway as this always happens after some minutes on 3000 rpm and 100km/h. Could someone help me with the correct part number? I have a 04 but with a m16a engine from a 04 liana.

The crank sensor has to be very close to the crank, on the M13 it is behind the alternator pointing at the front of the crankshaft from the side.

If your sensor was near the top of the engine on the front cover then it was the camshaft sensor, when this fails the engine usually keeps going but sets an error code.

Thank you! New part ordered. I hope this makes me able to take the old jimny ( my favourite car ) on the highway again. The feeling I got when the engine rpm goes bananas when i am deep down in a long tunnel made me avoid highways all together. I actually bought a new car just for highway use, so the Jimny could be used on country roads only. Hope the new sensor will fix it. Sorry for hijacking this tread.

Not at all the more info we get the better! Hopefully you and I both get sorted and can spin on the motorway in no time! Keep me posted.

Thanks again everyone!