Hi everyone, hoping for some advice! Just came back from holiday after having the car sitting for about a month. Unlocked and dash lit up, battery has good charge, but no fuel pump hum when turning the ignition and it won’t start. Best course of action here for diagnosing and fixing? First things to check? Thanks!
Did you check the battery with a meter, how old is the battery, where has it been parked?
Fuse layout if you want to check those…
Battery is relatively new, testing good and got it at full charge. Been parked on drive at home. Checked the fuel pump, starter and injector fuses and seem to be all good.
Sounded to be cranking, couple of clicks and nothing. Could be starter motor, but a bit lost here - don’t want to keep trying in case causes issue
Yep if accelerator pedal is fully pressed , car will crank but spark plugs don’t fire on the NC
Any tips or is it a recovery/garage job?
Maybe check for water ingress recently (if you’ve had rain in Cornwall) favourite entry point, if you’ve not already checked/sealed are the scuttle grommets. This can affect fuses in the passenger footwell if they get wet and throw up electrical gremlins. Another is rodent damage to wiring, it’s been standing a month. I had a mouse nest under the plastic engine cover on my first NC. No damage to wiring on that but they do chew through stuff like that. It’s not the weather ATM for mice to find a warmer home but you never know.
Cheers! Did check for water ingress from the grommets, but dry as a bone. Zero condensation or dampness around in the cabin either. Only re-did and silicone sealed them a few months back so that seems to be holding. Been in the engine bay checking the fuses and all looks okay wiring wise surface level, and took the boot cover panels off and same case for the fuel pump itself.
When you say couple of clicks is the engine turning over or is it just clicking?
If it’s just clicking that’s not the same as turning the engine over.
Doesn’t sound like the starter motor is kicking in - some light whirring and clicks, but could be the solenoid with the starter not actually going.
When I turn the ignition I hear a single click from the fuel pump behind the cabin, doesn’t sound like the usual low hum you hear when turning ignition on from the fuel pump, then if turn to start then the whirr, it trying, but doesn’t sounds like the starter motor.
Sorry my descriptions are probably really unhelpful I’m in new teritory here for me mech wise
You say battery has good charge. But have you checked the voltage?
I’m a donkey mate… I’d plugged it into my battery charger and the indicators were saying good at 12.3-12.6v but dug the old multimeter out, and it’s only reading 10.38V. On charge now and hoping that’s the root.
Lack of pump hum and all other electrics seeming fine might have got me jumping to wrong conclusions and over trusting the charger indicator. Thanks for the reminder. Will update tomorrow.
MX-5 MK3 are known to have a higher than normal parasitic drain on the battery and when left for a month few will have enough power in the battery to start the engine.
Many owners of MK3’s who leave their cars for longer periods leave a battery maintainer connected or disconnect the battery.