Jimny stutter

Let me introduce myself, I'm Bob from the Netherlands, I found a nice '99 g13bb Jimny a couple of months ago. It had some rust but the price was good so I bought it. When I drove it home the check engine light came on, a faulty lambda sensor, which I changed the week after and the engine light never lit up again.

The car really needed some service so I changed the oil+filter, plugs, distribution, airfilter, the standard stuff and it drove really well. However soon after the problems started. At half throttle it just won't go, at full throttle its not a racer but it pulls up to 90mph. At half throttle sometimes nothing happens and then suddenly it sprints away.

I've been reading these forums and quickly concluded it could be the camsensor, so that was the first thing to change but it didn't help. Fuel pressure was really low due to a faulty fuel pressure regulator, changing that sure made things better but still not good. I've double checked the timing on the belt and is good.

Problems seem to start when the engine is hot, there are no real problems when cold. And it revs up nicely when not under load. The fact that it does get up to top speed rules a lot of things out but right now I'm puzzled, I don't know where to start and I would really appreciate some assistance.

Yes I have

It's not an original but from a good local parts supplier, is there any way to test it?

I’m having a similar problem with an 05 vvt. Engine is fine when cool, then when warm suddenly loses power and almost stalls when at a stop, but when revved upto 3000 with no load turns over fine. Engine is very wobbly when problem occurs but to my ear doesn’t sound like a misfire. Changed crank sensor (not cam) with no joy. Sounds like cam sensor and new plugs leads & coil might be next on the list. No relevant engine faults showing up on the fault reader. Is there anything else that could cause an intermittent problem when engine is warm?
I’ll follow this post see if anyone else has more input.
Thanks and good luck Bob!

Get a cheap water sprayer bottle
fill it with cold water and when problem kicks in jump out and spray the crank sensor (behind alternator)
If it springs back to life when sensor is cold buy a new one of good quality

I often wonder about the throttle position sensor (TPS), which is in essence a potentiometer that spends most of its working life moving around. They are often overlooked but give essential feedback to the ECU on the throttle position so that the fueling is correct. If you have any old electronics in your home you know the volume control, which is also a potentiometer, often fails such that the volume control stops being linear ie. flat spots.
They are cheap enough but very don't get changed that often.
I am not say this is the cause of your problem, but it may be worth checking (or replacing) as a very last resort.
Interested in what corrects this problem, always difficult to be accurate with intermittent faults.
Mike

I don't think a g13bb has a crank sensor? I can't find anything behind the alternator

Kreidler wrote: I don't think a g13bb has a crank sensor? I can't find anything behind the alternator

I was replying to partho00 with the vvt

The tps gives a steady output and when turned it gives no stutter like you describe, I however do not know the exact resistance values it should be. I measured this in cold condition though