Jimny JB33W won't start - Wiring issue perhaps?

Hi all, I'm new here. I have a JB33W, not sure about the year, it's a hardtop with a G13B motor.

I've been experiencing some issues lately. I initially had issues with acceleration, she would start up fine, but would accelerate very slowly. The voltage on the IAC valve was off, and replaced it with a new unit. Yet it didn't change anything.

I took it to the local mechanic (I live in Africa where things aren't done in the correct standards as one would like), he determined that it's bad valves. They opened the head, found some major carbon build-up between the valve and stem on the exhaust side. After reinstalling the head, they over torqued the bolts which caused the block to break I then had taken the block to some welding "fundi's", afterwards had the block and head skimmed and fixed the thread for the block. Replaced the bearings, new piston rings, ect. Brand new engine, yippee!!!

The engine started, run well, but died after she became hot. Also, I didn't check if she accelerated correctly at that time. Now the issue is becoming worse...

Somehow, the CPS (camshaft position sensor) doesn't pick up the small pickup attached to the camshaft. I've swapped the CPS sensor, MAP, TPS, ECU and even the crankshaft itself, nothing seems to work and all parts from my Jimny works in the other one.

When reading the voltage from the CPS sensor on the ECU side I'm getting 0.31V and 5V. But yet I'm not getting any spark when cranking the engine. If I remove the CPS sensor and wave a piece of ferromagnetic material in front of it, I get a spark.

Thus, I tried sanding down the CPS sensor holder, and the engine started again, but died soon after the engine became hot. On the diagnostic tool I can see the timing advance dropping from 5 degrees down to -6 degrees and then she dies. Now I'm not getting a spark again and I don't think it would be wise to continue sanding down the CPS holder.

Also, I'm not getting any error codes, even while cranking.

Any help would be greatly appreciated.

Hi, so I've been going through the wiring diagram (99512_81A20_015) and a couple of posts. The main relay fuse has popped, I changed it but still no joy. The main relay fuse might have popped due to the fuel pump drawing too many amps.

I'm starting to think it could all be related to a bad battery, I read somewhere that the fuel pump draws a lot of amps which could cause the ECU to shut down yet the engine still cranks and thus doesn't send the signal to the injectors and ignition coils. Could it be something as simple as this???

Doesn't sound like you are having a good time with this. Unfortunately I don't understand electrics enough to offer meaningful advice. That said I too have read about batteries causing all kinds of odd problems. Good luck with it.

All sorts of problems occur with a bad battery, especially at low revs when the alternator does produce much power. A poor or failing alternator will also give the same sort of problems at high revs and can cause early failure of the battery.

Best to charge the battery up full and give it another go.

My other car developed a misfire after been in for an MOT/service. I went through plugs, coils, Mass Flow, fuel flush, air inlet and throttle body clean, the lot, everything made a slight difference but it was only when I charged the battery the misfire went. I have a battery monitor fitted and checked the data for the two days whilst it was in the garage, they must have left it unlocked with the keys as the battery went down to 9v overnight.

Reading your post, I think there may be another underlying problem, but if you can at least get it running again that will give a chance of fault finding the other issues.

Robin

I think you're right, it seems like a combination of a bad battery and an old starter motor.

I disconnected the injectors and removed the spark plugs, then cranked the engine with the spark plugs in. Thus lowering the compression and increasing the RMP. Then I had spark. I reinstalled all spark plugs, nothing again. Removed one spark plug and tried again, spark is back.

Regarding the acceleration issue, do you think that could be bad intake valves or something else?