‘08 Jimny Rough Idle

I use a generic obd2 scanner to look at values

And I use an app called Car Scanner, image attached.
I’ll disconnect the other battery, and see what happens.

The workshop manual does seem to indicate the existence of both a MAF and MAP but it is probably a year older than my model, so it may be slightly out of date.

I did have a thought, would the P0102 and P0113 codes be relevant to the idle and misfire codes? If it’s not likely, I could just focus on the cam sensor potentially being faulty and at the worst case, the VVT actuator being faulty or not being put back together correctly. If there’s anything else I should look at, I’ll try it out.

Thanks.

If the manual shows a MAP sensor and you can read the value direct from the ECU then it must have one.

Hey, so I’ve disconnected the second battery today, nothing really changed, but it’s nice to have a bit more space in the engine bay. The main battery has a charge of 12.4v, so slightly lower than with the second one connected. I might charge it and see if it does anything, but not holding my breath.

Had a look at the Camshaft Sensor today as well, fair bit of oil around that area and tape around the connector as shown in the photos. Could oil cause the connectors and pins to not work properly, which is causing the ECM to think the Camshaft isn’t advancing as it should? Didn’t manage to clean the connectors as but I wonder if it’s worth ordering a new sensor. Anyone know if I can buy a new connector harness as well?

Another thought I had for the idle was the injectors possibly being blocked or malfunctioning. Haven’t really tested the theory, but just throwing it out there to see what you guys think. 

Also just messaged the owner about any more info he can give me about the idle. He said the head was reconditioned early last year and was running perfectly until he started feeling the idle change from only a few months ago.
If the timing was off or if something was not put back together properly, would they feel it immediately or would it take a while for symptoms to appear?

Thanks

If the cam shaft timing was out you would see problems straight away.

As you didn’t see the cam timing code first time around it’s unlikely that the cam chain has been put back incorrectly.

A film of oil on a connector could cause some problems. Try getting some electrical contact cleaner (preferably one that doesn’t leave a residue) or failing that WD40 or similar and give the connectors a good clean.

Robin

Just cleaned the connector and sensor today, cleared the DTCs and went for a few drives.
The p0011 code did come back eventually, but I did notice it took a while for it to reappear into the system. It took about 4 driven cycles instead of the usual 2 for it to reappear into the system, and I was driving it increasingly more intensely. I also noticed that the code didn’t appear as soon as the idle started playing up, but I don’t know how relevant that is. Could heatsoak play a factor into the sensor getting a false reading, since the oil could possibly absorb heat quicker to a possibly faulty camshaft sensor? I wonder if it’s worth replacing the sensor or if I should just start taking apart the valve cover? Any other possible places to look at?

Interesting that P0011 (Camshaft timing) took longer to come up. Dirty contacts could change the output (if they introduce resistance) so it might be that you do have a sensor on the way out rather than a real fault.

Apart from the EGR code (you are going to get this as the valve is not fitted), did you also get all of the other error codes (misfire, etc) or are you now down to just two codes?

Robin

Hey Robin, just did a quick code scan. It looks like I'm down to two codes which are the EGR and camshaft timing code. I wonder why the other codes appeared before? I might order a new camshaft sensor and see if that hopefully changes things. I'll keep this thread posted

Thanks

Hey,

So I managed to get a new cam sensor and fitted it after cleaning the connector and wiring. Seemed to stay dry for about 2 days, then the connector was covered in oil again.

I cleared the codes after I replaced the sensor, and went for a drive on the freeway. There was a pending p0011 DTC, but then cleared by itself the day after. The code then reappeared two days after that as a confirmed DTC.

The idle hasn’t really improved either, so I’m not too sure where to go from here. The oil on the sensor might be coming from a weep from the back of the valve cover, so I might have a look at that.

One thing I found was that whenever the idle was bad, a temporary fix was to put the car in neutral and rev it up to about 5.5k then come back down, and it would be fine until quite a while later. 

I might also take it to a shop for diagnosis and repair, but it’ll be a while before I can do that. So if anyone has any suggestions, I’ll be happy to hear it.

Thanks

Have you tried the throttle position sensor.

Mine was reading high (17% at closed throttle) and didn't show up on the OBD scan, it gave me no end of problems until I correctly diagnosed it. A quick check would be to unplug it and see what happens when running on just the MAP sensor

Thanks Carl, I’ll have a look and let you know