Dodgy idle, and odd sounding exhaust.
Discussion
Hi chaps, I've unfortunately got a few problems at the moment that I'm hoping I can have some help with to fix.
1: I fitted a new 4-2-1 exhaust. I previously had the standard single piped Caterham example. My problem is that the exhaust sounds odd when driving. I liken it to having a playing card in your bikes spokes, and then spinning the wheel. This only occurs when the accelerator is pressed.
I'll try post up a sound clip this weekend as it's hard to describe.
2: My idle is up the swan. I'm having to rev it at junctions to prevent it from stalling. This problem only occurs when at very low revs e.g. sitting at tick over, creeping up to a junction.
It'll go from 1000 RPM steady, then blip to nothing then back again. The engine has to catch its self to prevent stalling. But at times it'll stall when the revs drop.
My thoughts are either the Lambda sensor or Idle Air Control Valve (IACV) could be at fault.
The lambda sensor I swapped over from the old exhaust to the knew, so I have put my jinxed hands on it.
The IACV just sounds like it should be at fault!?
I also think my car smells slightly of petrol. Would this tie in with an incorrect air/ fuel mixture issue pointing to a dodgy IACV?
1: I fitted a new 4-2-1 exhaust. I previously had the standard single piped Caterham example. My problem is that the exhaust sounds odd when driving. I liken it to having a playing card in your bikes spokes, and then spinning the wheel. This only occurs when the accelerator is pressed.
I'll try post up a sound clip this weekend as it's hard to describe.
2: My idle is up the swan. I'm having to rev it at junctions to prevent it from stalling. This problem only occurs when at very low revs e.g. sitting at tick over, creeping up to a junction.
It'll go from 1000 RPM steady, then blip to nothing then back again. The engine has to catch its self to prevent stalling. But at times it'll stall when the revs drop.
My thoughts are either the Lambda sensor or Idle Air Control Valve (IACV) could be at fault.
The lambda sensor I swapped over from the old exhaust to the knew, so I have put my jinxed hands on it.
The IACV just sounds like it should be at fault!?
I also think my car smells slightly of petrol. Would this tie in with an incorrect air/ fuel mixture issue pointing to a dodgy IACV?
The logical deduction capability of the average homo sapien never fails to amaze me. You fitted a new exhaust manifold and now have the classical sounds and symptoms of a cracked or blowing manifold or system yet deduce it might be the IACV or lambda sensor, neither of which could cause a funny noise, rather than the actual thing you just replaced. Extraordinary.
Pumaracing said:
The logical deduction capability of the average homo sapien never fails to amaze me. You fitted a new exhaust manifold and now have the classical sounds and symptoms of a cracked or blowing manifold or system yet deduce it might be the IACV or lambda sensor, neither of which could cause a funny noise, rather than the actual thing you just replaced. Extraordinary.
Would a badly sealed exhaust cause my erratic idle? Is the noise caused by a duff exhaust, or by a bad seal to the engine. Once again, guess what, I don't know, that's why i'm asking.
I'll try resealing the exhaust then.
Right. I've just fitted a new exhaust manifold gasket and I think (quite late now and raining hard, so didn't go for too long a run) my weird noise has gone, so hopefully I can say thanks for that chaps!
I still seem to have the erratic idle. What else could it be? Air leak between the throttle body and the head? I'll make sure the exhaust bolts are all still torqued up tomorrow after my run out.
I still seem to have the erratic idle. What else could it be? Air leak between the throttle body and the head? I'll make sure the exhaust bolts are all still torqued up tomorrow after my run out.
Edited by Gingerbread Man on Saturday 7th May 22:27
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