How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Matt Your Own Question
Matt, Mechanical Engineer
Category: UK Car
Satisfied Customers: 21607
Experience:  BEng hons Mech engineering, in auto industry 22 years
Type Your UK Car Question Here...
Matt is online now
A new question is answered every 9 seconds

My mx5 51 plate runs but wont fire, clicking noise on inlet

Customer Question

My mx5 51 plate runs but wont fire, clicking noise on inlet manifold, charge ligh flickering, car wont talk to scanner. Thanyou
Submitted: 1 year ago.
Category: UK Car
Expert:  Matt replied 1 year ago.


I'd 1st check that the main battery connections are on tight and they are corrosion free

Do the same for the engine / gearbox earth strap.
Then follow the main positive lead back to the engine and down to the starter motor, and check the connection at this end as well.

There should also be a small wire to the motor which should have 12V when you're turning the ignition switch to crank. If the 12V isn't there, check back along this wire for damage to the insulation or corroded connections

This 12V feed comes directly from the ignition switch so this may be faulty and need replacing

Check the resistance of the main positive lead that runs down to the motor as anything more than a few ohms and it should be replaced

Don't forget totry a jump start from another car / battery as its possible the battery ispoor, if you have a voltmeter a healthy battery should read 12.7+V

also trysubstituting the battery for another as I've known a very flat battery to dragdown the system voltage too far even with jump cables

Customer: replied 1 year ago.
Had auto electrican round and he checked round and two scanners and he seems to think ecu. Thank you
Expert:  Matt replied 1 year ago.


Ok if the ECU is faulty then you can get all sorts of odd issues 1st check if the ECU is getting power

if it is then check that the small ECU earth wires that run out of the engine bay wirign loom and are secured to the engine with ring terminals

if this is all OK then send the ECU off for testing

Expert:  Matt replied 1 year ago.


do you still need help?