iddling issues HELP NEEDED

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iddling issues HELP NEEDED

Postby Deanmnorris » Thu Jan 07, 2016 8:07 pm

Hi guys new to the forum and mx5 scene and needing some help please with my mk2 1.6

problem started one day when i turned the car on and the revs sat at 2000 rpm i drove ome and when stationary the revs would fluctuate between 1500 and 2000 rpm as if i was tapping the accelerator

so far i have

checked for air leaks
changed the spark plugs and leads
swapped mafs to a new one and a used one
cleaned the idle control valve with the proper solution

now need help not managed to find anybody with a spare valve to try but getting desperate haha.
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Re: iddling issues HELP NEEDED

Postby drumtochty » Thu Jan 07, 2016 9:36 pm

What year is the car, you say it is a Mk2 can you confirm that it is not a Mk2.5.

If it is a mk2.

Get one of these and do a flash test to check for error codes, the instructions are with the kit. ... 6665-p.asp

Also lift the carpet on the passenger side of the car, that does not mean just feel the top of the carpet.

Where the passengers feet would be on the front firewall or bulkhead there are two silverish boxes ( as it is a 1.6 therefore probably no ABS maybe only one box) about the size of a large ciggarette packet held done by a cover.

On the Mk2 the boxes are covered by a metal cover.

Is the cover rusty and is there any water about the area.

If there is water there you will have to clear the drains behind the seatbelt towers one at each side.

Have you checked these drains with a trombone brush and also the eight little drains at the back and front of each of the four jacking points with a little screwdriver
99 Mk2 1.8 IS Silver
08 Mk3 2.0 RC Sport Copper Red Sold
18 Mk4 2.0 GT+
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Re: iddling issues HELP NEEDED

Postby Deanmnorris » Fri Jan 08, 2016 8:08 am

thank you for the reply.

the car is a 1999 mk2 I'm lead to believe. I will lift back the carpet tonight and have a good look I made sure the drain holes were clear when I bought the car so hoping this isn't the case.

is the wee box in the footwear relative to idling is it a control module of some sorts ?
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Re: iddling issues HELP NEEDED

Postby OldSpice » Fri Jan 08, 2016 8:38 am

It's the ECU..Electronic Control Unit.
It's in charge of almost everything..including blood pressure & heart rates. :wink:
If it gets even damp, not saturated, it can rebel.

I'd be whipping off the coil-pack leads out the coil-pack end AGAIN, and ensuring they are clean & tight, and work my way forward to the plug lead ends.
Also, check the wiring loom to the injectors...they are beginning to fail with age, especially the one nearest the radiator although it does not read like that's the issue it's still worth checking them out. I know you've checked, but it sounds like air leaks to me.
I'm on my second injection loom on a '94 incidentally.
With these old cars, anything can happen in the next hour :shock: as mentioned I'd have it check with a plug-in fault finder.
Fault finders don't always give the answer, but even forgotten components like the fuel filter can deceive.
There will always be an imbecile you never bargained on within slapping distance.
You can never underestimate the stupidity of the general public
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