[rhino8]

HI all

Really hoping someone can help me out with my VVT Auto Jimny issue as right now, I can't drive it until my issue is fixed.
It's driving me slightly crazy ...

[b]Symptoms[/b]

When driving, and slowing down to lights and coming to a stand still and idle, randomly, whist still in gear it will shudder/sputter like it is about to stall. Sometimes by hitting the throttle at that very moment it can be recovered. On the highway it can sometimes sound like its missing or sticking then comes good and revs well. If the RPM is manually held higher, it generally wont happen and if it does, it will recover without a stall.

Sometimes, it happens too quickly and it just stalls when idle. At this point, 9 times out of 10 a restart is nearly impossible.
It cranks fine, but will not fire & start. The only way I have had success in restarting is to leave it for 10mins to nearly 1 hour - again it's quite random After numerous attempts, it just fires and starts. I have also tried letting it sit for 30 sections, priming it, and repeating a few times, but doesn't seem to help.

Randomly, it can be driven a short distance, parked, left for 5 mins 10mins - 1 hour, return to car and it will crank but not fire/start

It actually drives well and since the exhaust and throttle-body clean out there is a noticeable difference in acceleration and power.

[b]Replaced/added/performed[/b]

[b]old changes[/b]
1 year ago replaced coil packs had a weird random stutter on idle, replacing both coil packs at the same time fixed this.
1.5 years ago replaced rocker gasket and tube seals as oil found on spark plug wells & plugs.

in the last few months
Cam Sensor
Crank Angle Sensor
New exhaust, extractors with EGR pipe, 2" with hi flow cat
throttle body clean-out

[b]Tested by garage[/b]

Fuel Pressure - low end but still ok (garage advised this after connecting pressure gauges)
Battery - Low but still cranks fine - no ECU alarms
Oil Pressure - tested ok - no ECU alarms
relays and fuses
They couldn't replicate the problem, but a day after it cutout and took 10mins to restart.

I found the following a few days ago whilst trying to figure out the cause of the issue

Oil in spark plug well #1
PCV valve - gritty, but was opening and closing on the spring. Pushed the valve in and it did stick but a shake and it popped back out. Needs a replace


[b]Things to note[/b]

* Always starts when completely cold first go but does generally idle a little rougher - sometimes (no visible misfire or rough like a total misfire)

I need suggestions here on what it might be

We thought maybe immobiliser however the lock on the dash always dissapears - and I don't have a second key to test.
I need to change the rocker gasket and tube seals - could this issue cause the symptoms ?
Could the PCV be causing this issue ? Would that alone cause a car to stall and not restart sometimes for awhile, and sometimes straight away ?

Appreciate any suggestions to what it may be

[greyghost]

gee it kinda sound electrical, like a coil breaking down. i doubt that its the
and electrical faults get worse as the electrical component heats up/resistance gets higher.
intermittent faults like this can be real hard to narrow down.
i would be looking at the cam/crank sensors and coil packs. however the fuel pressure is low so start there, change the filter and pump and eliminate this.
swap out for "known" good ones, and remember just because its new doesn't mean that its good.
what ever you do, only change one item at a time and test the car to make the fault reappear, if the fault repairs then move onto the next item in the list.

[Gwagensteve]

Fuel pressure.

I bet the workshop checked pressure with the engine idling.

fuel filter screen/fuel pump/fuel pressure regulator would be my next ports of call.

Steve.

[fordem]

Gwagensteve wrote:

Fuel pressure.

X2

[losfer]

why does it start 1st time every time when cold if its fuel pressure ?

[frak]

Could be rubbish in the tank that intermittently plugs up the lint into the pump.

If u had a fuel pressure gauge fitted you would certainly see a pressure drop when it stutters.

[rhino8]

thanks guys all good suggestions and gives me a way forward. Does anyone have a guide/info on swapping out the fuel items ?

[fordem]

losfer wrote:

why does it start 1st time every time when cold if its fuel pressure ?

With no fuel being used (no injection until the engine is started) the pressure should be slightly higher.

[Gwagensteve]

Yep. Pump runs for 3 seconds, builds sufficient pressure to start the car. The fuel pump runs as hard at idle as it does when the engine is at full load. If the pump is dying or the screen blocked it won't show until a prolonged period at high load.

[rhino8]

Why do you think it would take some time to come good while its shut off / wont start ? Simply something blocked or is it something / pressure that has to clear / change ?

[rhino8]

What do you think is happening when it sits after a stall and can' be restarted ?
Is it just that the pressure has to change, or the blockage simply has to sit until it unblocks itself ?

[vet 180]

Sounds electrical/spark / ignition as it happens when the engine is warm. Fuel pressure doesn't explain the driving and sitting for up to 30 mins unless the fuel pump is heating up and losing effiency due to a blockage or its just shagged

[Gwagensteve]

That's exactly my theory. The normal cultprit (cam position sensor- and almost everything else) has been eliminated.

[rhino8]

I'll do the gasket, plugs and leads , if still there I'll look at the coils again, then fuel - so sick of dropping $$!


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