Discussion
Supposed to be leaving for Eastern Germany on Wednesday in our TVR S3 that we recently purchased, now all of a sudden it is running like a pig!! Removing the plugs they are black, replaced them with new plugs and after just a few minutes running plugs are black again, so I assume she is over fuelling, can't get an even tick-over and backfiring through the exhaust, I've pulled off every plug off every sensor can't find the ECU so as you can imagine I'm panicking, anybody have any advise on how to cure otherwise I have to take the granny mobile which I really don't want to do
Have you tried disconnecting the TPS sensor ? Oh and do you still have the dreaded yellow connector under the steering wheel ? air leak and connectors to all the sensors on the right hand bank of cylinders ? sure someone else will be along with more suggestions
Edited by ChrisGadd on Monday 8th August 15:21
Edited by ChrisGadd on Monday 8th August 15:26
Let's be diagnostic about this... Are the plugs black and sooty, or black and shiny? Do they smell of fuel or of oil? Are all 6 plugs the same? Is this with the engine properly warmed up (a cold engine will tend to foul the plugs due to cold start enrichment).
If they are, it's most likely a fuel fault. Forget the yellow connector - not symptomatic of this problem. As Chris says, disconnect the throttle pot and idle speed valve on the front of the plenum - that puts the engine in "lp home" and bypasses the ecu fuel maps etc. If it's still too rich on those basic settings then have you been working on the injectors or fuel regulator?
Again as Chris says - Check the big connector under the coil on the RH rocker cover. That takes all the sensor signals back to the ecu, could be fooling the ecu into thinking the engine is cold. Also the coolant sensor under the throttle butterfly housing might have failed, causing that same effect.
If they are, it's most likely a fuel fault. Forget the yellow connector - not symptomatic of this problem. As Chris says, disconnect the throttle pot and idle speed valve on the front of the plenum - that puts the engine in "lp home" and bypasses the ecu fuel maps etc. If it's still too rich on those basic settings then have you been working on the injectors or fuel regulator?
Again as Chris says - Check the big connector under the coil on the RH rocker cover. That takes all the sensor signals back to the ecu, could be fooling the ecu into thinking the engine is cold. Also the coolant sensor under the throttle butterfly housing might have failed, causing that same effect.
Sounds like either an air leak, not the most likely - check all the intake hoses - vacuum take off from plemun chamber to servo and the servo itself. Shove your hand under the servo and see if the 'can' is badly rusted, or the throttle pot sensor thinking its at max revs - so shoving fuel out.
The plugs are sooty and all six changed for new one's, car was fine, had just done a 250 mile trip and next morning had trouble starting and tick over seems float up and down till it stops, then throttle on the floor it takes a while to start, on the move it's like its missing and pops through the exhaust.
Just been out and disconnected the throttle pot and idle speed controller, started the car up and everything seems fine. Easy starting, good tick over, connected the idle speed controller valve and still the same, connected the throttle pot and back to how she was! So I assume it's the throttle pot!
I'm down in Kent in the Medway Towns anyone know anyone who might have one on a shelf, as I need it tomorrow? Or what if I keep it disconnected and do 1200 miles, will I get home??
I'm down in Kent in the Medway Towns anyone know anyone who might have one on a shelf, as I need it tomorrow? Or what if I keep it disconnected and do 1200 miles, will I get home??
If it is the throttle pot then the way I see it you have 2 options, first go to your local scrappy and pillage any rover 16v K series car for their throttle pot or get to your local motor factors and get a new one Intermotor part number is 19935, I know it is of no use to you now but I always carry a spare just in case, good luck
Cheers.....Tony..
Cheers.....Tony..
locust32 said:
Just been out and disconnected the throttle pot and idle speed controller, started the car up and everything seems fine. Easy starting, good tick over, connected the idle speed controller valve and still the same, connected the throttle pot and back to how she was! So I assume it's the throttle pot!
I'm down in Kent in the Medway Towns anyone know anyone who might have one on a shelf, as I need it tomorrow? Or what if I keep it disconnected and do 1200 miles, will I get home??
As I said earlier, disconnecting the TP pot puts the engine into a "diagnostic" mode and bypasses the ECU fuel maps etc - so as it works with the TP disconnected, then it might be the TP, or it still might be any of the other sensors or their connectors, or the ECU itself. I'm down in Kent in the Medway Towns anyone know anyone who might have one on a shelf, as I need it tomorrow? Or what if I keep it disconnected and do 1200 miles, will I get home??
It's worth changing the TP if you can get one, but if that doesn't work, try disconnecting the battery for a few minutes, see if that re-starts the ECU in a better frame of mind (it should reset any corrective maps it's applying)!
Can you borrow a fault code reader?
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