I’m having a problem with my MK 1 1.6 1992 cutting out when slowing down. It won’t idle. It does it when cold or warm. Some days it doesn’t do it and others it does. It seems to be worse when not driven for a few days. It is getting worse and a bit dangerous as I loose the power steering when it happens. It was only driven a total of 900km over the two Covid years 2020-2022 and is now being driven regularly so I need to get the problem fixed. Does anyone have any ideas?
- My model of MX-5 is: NA
- I’m based near: Cambridge
- I’m looking for technical help or recommendations on: cutting out problem_
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First thing to check is the base idle, search TEN - GND on the forum should find you instructions on how to check it.
Thanks Robbie, you showed me how to adjust this years ago but when we tried it this time it didn’t seem to make any difference so I wasn’t sure if we were adjusting the right thing? I will get my brother in law to have a look at this.
Is this happening when you are pressing the clutch in to slow or come to a stop?.
M-m
I had this with my early '89 Eunos.
It would do it when hot, approaching a roundabout. As I changed down it would cut out and I would have to declutch and bump start it on the hoof. Like you, just every now and again.
I also had an occasional issue with cold starting, needing to blip the throttle to keep it going. After half a mile it would settle down. I was as if the battery had been flat and the ECU had lost its memory and needed 5 minutes to re-learn everything.
Hi, yes but not just when I press the clutch, basically as soon as I take my foot off the accelerator to brake.
I would first check for any damp under the carpet around the ECU, check the flash codes and make sure the battery is in good condition holding a healthy charge, and that the alternator is kicking in a healthy charge, then we can move on from there to possibly AFM or temp sensor reading wrong.
M-m
I had also had a clicking sound from behind the centre of the dashboard, similar to when you are trying to start with a flat battery. Could that be alternator not doing its stuff on higher revs and running the battery down?
My 07 NC 1.8 did similar, tick over dropped dangerously low. Bought some fuel system cleaner, cured problem, great buy
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Clutch switch would have been my guess but we never did hear back constructively, from the original, apparently ungrateful poster, so who knows.
She did say that the clutch pedal was not involved but that would not deflect my theory in the slightest.
Karen’s car is all sorted now. It did need a clutch switch repair but ultimately the cause was a failed idle control valve.
It would have been nice to hear back from Karen, Robbie, that is how we all learn and move forward.
On the MK1 1.6, a typically dead ICV causes higher revs, so typically from my testing 1250rpm to a crescendo of 1500 rpm when fully warmed up. What are the usual symptoms of a failed 1.8 ICV please?
These parts, particularly the 1.6 are starting to show their age. I sold one that showed the correct resistance but did not work at all in operation. the other two I had in stock worked but had blocked waterways. to unblock compacted rust on the 90 degree pipe side, going to have to cut off the pipe, unblock and then weld the pipe back on. Tried everything else but any other ideas gratefully received.
I’ve no experience of 1.8 IAC failure so not had the need to look into their operation.
Do you still have your racing machine, merlot 1.8:-)
Please try disconnecting the ICV plug and see what happens.
When I did this with the 1.6, it mirrored failure symptoms
Still got the Merlot but it’s not had a battery on it for the last 2 months. Once it’s out of hibernation I’ll give it a go.
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Sounds like fuel starvation to me. My Haynes manual says dirty injectors or air leak at throttle body, Fuel system cleaner cured dirty injectors for a few pounds and problem for me. Had throttle body off to do thermostat since, cleaned around reused gasket, bit pricy new for what it is. All going great.