High idle and fuel smell in cabin while driving

Technical Area Engine, Transmission, Exhaust etc
1
  1. My model of MX-5 is: __ 2001 Mazda MX-5 mk2.5 1.8 sport vt
  2. I’m based near: __beaumaris Anglesey
  3. I’m looking for technical help or recommendations on: __

Hi all

I have a huge problem. My MX-5 runs at 1500RPM when idle and there is a really bad smell of fuel in the cab. Also it stalls in 1st and reverse gear

Any advice is much appreciated

Thanks

2

I can’t help with the idle but for the fuel smell remove the filler cap inspect the rubber seal for damage and if all good replace the filler cap then tighten until it clicks once. This may or may not help with the idle but probably will not.

3

Is this something that’s just started happening?

Does it do it from cold?

4

It’s been there for a while. Idle is high when cold but lowers slightly to around 1200rpm when warming up. Happens every time I start it even if it is already warm. And the smell is there at idle and while driving

5

Have also checked the fuel cap and it looks ok

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6

Just make sure the cap is very tight plus one click, it really makes a difference on mine. Looks like you might have to follow the fuel lines for sign of leak or blocked egr.

7

For the idle speed, have you checked and/or adjusted the base idle speed?

8

Thanks for your message. I haven’t checked or adjusted the base idle speed yet. I’ll look into that and get back to you once I’ve had a chance to inspect it. If you have any specific steps or recommendations on how to properly check it for this setup could you please let me know as I am unsure how to check it.

Thanks

9

I wondered if it was running very rich due to the ECU coolant temperature sensor failing, but that doesn’t sound to be the case if it’s better once it’s warmed up.

High idle & stalling could be due to a vacuum leak - can you hear anything hissing under the bonnet?

It wouldn’t explain the petrol smell.

10

There’s no hissing noise but there is a ticking noise cold and warm at idle. I don’t think it’s lifter tick but I could be wrong

11

Not an expert by any stretch of the imagination but I did once have a Westfield with the 1800 Mazda engine do something similar, turned out to be the tank vent valve that had failed.

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