Hi all!
- My model of MX-5 is: 2004 NBFL Euphonic 1.8L
- I’m based near: Banstead, Surrey
- I’m looking for technical help or recommendations on: Intermittent issue, engine cutting out.
Intermittent problem with the engine cutting out. Usually at low revs when stationary but it has happened while accelerating. The engine doesn’t drop its revs or sound like it’s struggling. It just cuts out like the ignition has been turned off. It starts up again after the 2nd or 3rd attempt and when it does start, it doesn’t struggle at all. One time it cut out when accelerating away in 2nd gear. It wasn’t at high revs but they were climbing. Just before this happened I was accelerating in 2nd and the car jolted forward twice like the revs had suddenly jumped up. These issues only seem to happen when the engine has been warmed up but after 25 minutes of driving it doesn’t seem to happen again.
I have cleaned the MAF, throttle body and idle control valve to no avail. I also checked the battery terminals which were fine. I’m wondering if the idle control valve needs adjusting or replacing. Any input will be greatly appreciated.
Many thanks,
Alex
Maybe TPS? Make sure the bolts aren’t loose. I would also check the main chassis grounds to make sure they’re ok.
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Crank sensor? (Or the wiring from it rubbing on the back of the crank pulley?)
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So I replaced the crank and cam sensor in August last year so I think it’s very unlikely that one of them would of gone again so soon.
After checking obvious engine and battery earth straps getting OBD2 codes would be my next priority to help me take some of the guess work out of finding the source of the problem. Good luck.
Sorry I forgot to mention this. After it first started happening I took it to my mechanic who plugged his diag machine in… Alas, no codes
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I think the next step is to replace the crank shaft sensor with the original one that I took off. I replaced it with an aftermarket one from mx5 parts but it wasn’t actually the issue. So the original one should be fine.
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I’m hoping the issue has been solved. I was inspecting the crankshaft sensor. The wiring was fine and not in any position to be rubbing on the pulleys. However, I noticed that the sensor itself was quite close to the pulley. I gave it a wiggle and it moved with only a little force. There was also a line on the sensor face which correlates to the pulley notch. I moved the sensor to the correct position and tightened it down. Took for a 20 min drive and I didn’t have any issues. I think the engine vibrations were causing the sensor to edge towards the pulley until the notch collided with it, causing the engine to cut out and throwing the sensor back out. I think it happened at idle more often due to the stronger vibrations at idle. Will monitor but hopefully that’s the end of it.
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