Won't idle, loss of power
Discussion
Had an issue today (second day of car back on the road from winter) that I also had once towards the end of summer.
Car runs fine but after returning to it after a couple of hours it won't hold an idle and dies. It's gutless when you can get it up over 3000rpm to stop it stalling and runs very lumpy below before eventually stalling and then not restarting as if flooded.
On each occasion it has generally sorted itself out. The last time I just left it overnight and then it was fine and this time it sorted itself after I got it to a garage and filled up.
I'm guessing that it is the ECU getting its nickers in a twist but I wondered if the symptoms might suggest something like a lamda sensor packing up? Car naturally runs a little rich and I also don't often get the opportunity to give it a sound thrashing so I was wondering whether the sensor getting sorted up might be the trigger?
Car runs fine but after returning to it after a couple of hours it won't hold an idle and dies. It's gutless when you can get it up over 3000rpm to stop it stalling and runs very lumpy below before eventually stalling and then not restarting as if flooded.
On each occasion it has generally sorted itself out. The last time I just left it overnight and then it was fine and this time it sorted itself after I got it to a garage and filled up.
I'm guessing that it is the ECU getting its nickers in a twist but I wondered if the symptoms might suggest something like a lamda sensor packing up? Car naturally runs a little rich and I also don't often get the opportunity to give it a sound thrashing so I was wondering whether the sensor getting sorted up might be the trigger?
Do you have the diagnostic software so you could view the signal of both throttle position sensors (tps) whilst cranking?
I had one of them go to 43% when trying to start a hot engine without even having a foot on the throttle pedal. Obviously this flooded the engine and required prodding the pedal to keep the engine sort of running.
Long story short, providing the lambda sensors with a ground directly from the battery terminal instead of sharing ground with the tps through the wiring loom cured that.
I had one of them go to 43% when trying to start a hot engine without even having a foot on the throttle pedal. Obviously this flooded the engine and required prodding the pedal to keep the engine sort of running.
Long story short, providing the lambda sensors with a ground directly from the battery terminal instead of sharing ground with the tps through the wiring loom cured that.
Presumably your running an idle valve as Ryan set out in the original prototype for RG. I'd start there and look for unmetered air then look at things like the ignition amp, cam position sensor. The fff syvecs cars are set up fairly differently to standard. Woodys probably your best bet.
gruffalo said:
Lamda sensors not used over 3000 rpm so it shouldn't be them.
You say it ran OK after filling up, have to checked the carbon canister and the tank vents as it sounds like it may be forming a vacuum in the fuel tank.
I did wonder if it was a fuelling vacuum so did open the tank but that didn't resolve the issue at the time. You say it ran OK after filling up, have to checked the carbon canister and the tank vents as it sounds like it may be forming a vacuum in the fuel tank.
If the sensors aren't used above 3000 then it is possible that supports my theory.
But I am also wondering if the bug is fixed to when I change the settings on the TC.
I think the key will be to try and note more things should it crop up again.
m4tti said:
Presumably your running an idle valve as Ryan set out in the original prototype for RG. I'd start there and look for unmetered air then look at things like the ignition amp, cam position sensor. The fff syvecs cars are set up fairly differently to standard. Woodys probably your best bet.
Just got it back from Woody. 
Mine was one of the first that Ryan mapped and it has also never been revisited since being run in so at some point this year I ought to try and pin Ryan down to remap it from scratch.
DonkeyApple said:
gruffalo said:
Lamda sensors not used over 3000 rpm so it shouldn't be them.
You say it ran OK after filling up, have to checked the carbon canister and the tank vents as it sounds like it may be forming a vacuum in the fuel tank.
I did wonder if it was a fuelling vacuum so did open the tank but that didn't resolve the issue at the time. You say it ran OK after filling up, have to checked the carbon canister and the tank vents as it sounds like it may be forming a vacuum in the fuel tank.
If the sensors aren't used above 3000 then it is possible that supports my theory.
But I am also wondering if the bug is fixed to when I change the settings on the TC.
I think the key will be to try and note more things should it crop up again.
If not the Lamda thing over 3000rpm could be completely wrong if you are using wide band Lamda's on a different ECU.
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