08 LX570 Misfire and stalling (No Codes) (1 Viewer)

[KRR]

Hi All,

I'm having a bit of an issue here with my110k miles Harrop Supercharged '08 LX570 hopefully others can help diagnose or advise with the issue i'm having.

Two days ago while waiting at a stoplight, put the car in neutral and all of a sudden it started stumbling and misfiring for almost 10 seconds then it was all normal. Scanned it with no fault codes.

Today, while at a freeway off-ramp it lost power and died. I managed to stop on the side of the road, no check engine / VSC light. Started it up like nothing happened. The only evident issue was that the car momentarily was hunting gears when accelerating, then returned normal. Got home, scanned it and again... no fault codes.

Here are the list of recently replaced items:
- DW Fuel Pump (6 months old, part of the Harrop Kit)
- DW Injectors (6 months old, part of the Harrop Kit)
- 83mm Throttle Body (6 months old)
- Throttle position sensor (6 months old, preventive maintenance)
- 1 step colder plugs (6 months old)
- MAF Sensor (1 year ago as preventive maintenance)

Without any fault codes, please advise if i should replace all 8 coils, crankshaft position sensor & camshaft position sensor as preventive maintenance? Or are there other issues which needs to be looked at?

Appreciate your input guys!

 

[AcmeSys]

Could be a load of bad fuel? Might try a hot mix of 100 octane unleaded race fuel + techron and the Italian tune up to try flushing any crud thru.

Is this on a stock ECU tune? Indonesian rigs have the OEM fuel filter on the frame rail?

After ruling out fuel, I'd start at reading the plugs and confirming fuel pressure. I think a few of these bolt on blower kits run a different fuel pressure regulator so check what fuel pressure it is supposed to be running at with engine off, at idle, full power pull, and 5 minutes after shutdown.

 

[KRR]

Could be a load of bad fuel? Might try a hot mix of 100 octane unleaded race fuel + techron and the Italian tune up to try flushing any crud thru.

Is this on a stock ECU tune? Indonesian rigs have the OEM fuel filter on the frame rail?

After ruling out fuel, I'd start at reading the plugs and confirming fuel pressure. I think a few of these bolt on blower kits run a different fuel pressure regulator so check what fuel pressure it is supposed to be running at with engine off, at idle, full power pull, and 5 minutes after shutdown.

Bad fuel is what im assuming as well, however i only buy premium gas at Shell Gas Station, the state owned gas stations doesn't have the octane consistency as Shell.

The car is stage 2 with 80mm pulleys Remote tuned by Kanoo Performance. The fuel filter i believe is inside the tank and was replaced when installing the DW Fuel Pump.

DW aftermarket fuel pressure regulator is installed rated at 50psi. Definitely will go and check out the plugs and everything else for abnormalities.

 

[AcmeSys]

if it is an easy swap - you might consider swapping the party pulley for an 85 if this problem continues

 

[KRR]

if it is an easy swap - you might consider swapping the party pulley for an 85 if this problem continues

Swapping it is easy. However I will need to retune it.

Just curious if replacing the crankshaft and camshaft sensor will fix it. It's been two days, the issue has not popped up again.

 

[AcmeSys]

without seeing what your flashed tune does to the ECU and trouble code over riding/logging- its hard to say what the issue is without digging into the rig. normally you'd pop a DTC if you have a detected misfire from crank/cam speed sensors or a coil pack error with a failed ingnitor circuit.

if they are cheap enough, go ahead and swap them (placebo parts swaps do actually work) but I'd lean towards plugs and fuel before a sensor issue for an intermittent idle stumble. pull the plugs and see how they look for a first step to check overall health then verify fuel pressure then injector testing and dyno time if it is a repeatable thing.

 

[ROM]

Hi All,

I'm having a bit of an issue here with my110k miles Harrop Supercharged '08 LX570 hopefully others can help diagnose or advise with the issue i'm having.

Two days ago while waiting at a stoplight, put the car in neutral and all of a sudden it started stumbling and misfiring for almost 10 seconds then it was all normal. Scanned it with no fault codes.

Today, while at a freeway off-ramp it lost power and died. I managed to stop on the side of the road, no check engine / VSC light. Started it up like nothing happened. The only evident issue was that the car momentarily was hunting gears when accelerating, then returned normal. Got home, scanned it and again... no fault codes.

Here are the list of recently replaced items:
- DW Fuel Pump (6 months old, part of the Harrop Kit)
- DW Injectors (6 months old, part of the Harrop Kit)
- 83mm Throttle Body (6 months old)
- Throttle position sensor (6 months old, preventive maintenance)
- 1 step colder plugs (6 months old)
- MAF Sensor (1 year ago as preventive maintenance)

Without any fault codes, please advise if i should replace all 8 coils, crankshaft position sensor & camshaft position sensor as preventive maintenance? Or are there other issues which needs to be looked at?

Appreciate your input guys!

KRR, Unfortunately you need to tune the correct injector values and the MAF rescale. If you confirmed that the fuel pump is working properly? What tuner software did they used to program your ECU? One suggestion to baseline the setup, return the bigger pulley, stock injectors and the stock ECU tune. It should run just fine as this is Harrop original scheme.

 

[KRR]

KRR, Unfortunately you need to tune the correct injector values and the MAF rescale. If you confirmed that the fuel pump is working properly? What tuner software did they used to program your ECU? One suggestion to baseline the setup, return the bigger pulley, stock injectors and the stock ECU tune. It should run just fine as this is Harrop original scheme.

That's already done by a professional tuner from overseas, using bitbox software . The 80mm pulleys were purchased from Harrop and I don't think that's the issue.

As others have said I'm leaning towards fueling issue, either bad batch of fuel or dirt got into the injectors?

 

[ROM]

That's already done by a professional tuner from overseas, using bitbox software . The 80mm pulleys were purchased from Harrop and I don't think that's the issue.

As others have said I'm leaning towards fueling issue, either bad batch of fuel or dirt got into the injectors?

Close thing i could relate is the weird check engine when i use the Harrop manifold AIT. Before i usually gets it when after a quick stop from a freeway restroom break or long traffic on hot summer days. I did the experiment switching back and forth between the factory and Harrop AIT. For sure the Harrop manifold AIT more often give this issue. I blame it on the heat soak due to the large aluminum mass from the Harrop Supercharger transferred to the AIT sensor. On top of that, i'm am certain the thermistor coefficient between the two are totally different. My current configuration used the factory. When i get this check engine, no apparent change on car performance. I get some unrelated error that simple reset fix makes it go away. Someday when i have more time, i'll investigate and compare the two devices.