I have a 2000 P38 V8 4.6 running on petrol/LPG. She has had a rough running problem and think I've gone down a couple of blind alleys.
The engine starts no problem but seems to hunt for a steady idle. If driven the hunting continues to the point of sometimes stalling if stopped at lights etc. However the "stall" happens even when driving - I feel the loss of power momentarily but the motion of the car keeps it running until it picks up again (quickly). Doesn't feel like a mis-fire but like a stalled engine
This was intermittent, ie I could go for a run like this but after a short distance switch off and on again and she ran beautifully. Smooth, no hunting and plenty of power.
The intermittent nature lead me to an electrical fault so have checked fuses, relays, fuse boxes, battery & alternator and connections. All good.
Have replaced MAF & O2 sensors which seemed to make a difference for a while but then back to fault.
Have checked obvious on ignition - no arcing and appears reasonable spark (she ran on all 8 smoothly). No obvious leaks, tired hoses etc.
Problem is same irrespective of running on LPG or petrol.
Don't have easy access to diagnostics (will mean a day of work to take it to nearest indie) and not really confident driving 20/30 miles with it like this.
I get both gearbox fault and traction fault messages but not always. On start up I sometimes don't but it comes as soon as I start driving. When she runs well the gearbox fault has cleared. It also seems the problem is worse between 1500 - 2000 rpm (but may just be me).
Any thoughts (apart from the obvious of plug in diagnostics
)
Sorry to be long winded.
The engine starts no problem but seems to hunt for a steady idle. If driven the hunting continues to the point of sometimes stalling if stopped at lights etc. However the "stall" happens even when driving - I feel the loss of power momentarily but the motion of the car keeps it running until it picks up again (quickly). Doesn't feel like a mis-fire but like a stalled engine
This was intermittent, ie I could go for a run like this but after a short distance switch off and on again and she ran beautifully. Smooth, no hunting and plenty of power.
The intermittent nature lead me to an electrical fault so have checked fuses, relays, fuse boxes, battery & alternator and connections. All good.
Have replaced MAF & O2 sensors which seemed to make a difference for a while but then back to fault.
Have checked obvious on ignition - no arcing and appears reasonable spark (she ran on all 8 smoothly). No obvious leaks, tired hoses etc.
Problem is same irrespective of running on LPG or petrol.
Don't have easy access to diagnostics (will mean a day of work to take it to nearest indie) and not really confident driving 20/30 miles with it like this.
I get both gearbox fault and traction fault messages but not always. On start up I sometimes don't but it comes as soon as I start driving. When she runs well the gearbox fault has cleared. It also seems the problem is worse between 1500 - 2000 rpm (but may just be me).
Any thoughts (apart from the obvious of plug in diagnostics
)Sorry to be long winded.
