Car wont start. Help!

[robin]

Yeah, do it ... worst case when you need to start the car you pop the boot, neutral, handbrake, immob off, ignition on & then jump out and hotwire it in the boot (I once had to do this whilst facing the wrong way on a race track after a friend had spun my car in a somewhat ambitious attempt to carry more speed into the corner ) - I ran the car like that for months and months before I bothered fixing it. Just keep the right bit of wire in the boot - takes 15 seconds max.

Cheers,
Robin

[jammacdo]

After its well timed failure and letting me test the hot-wire approach in the comfort of my own garage and of course then starting on the button every time whilst in Manchester the past two days I got home ok this evening. So now just need to replace the bits I need so I don't have the embarrassment of a "flash" car that wont start.

I don't seem to see a solenoid replacement only, but they seem to come as a whole starter motor. Is that correct?

Ps - was sitting at Kendal services when a chap walks up to me and says hello. Turns out he had his Exige S (and its was a stunner) with him and wanted to come over and chat. Was nice to meet another Lotus person in the flesh. Was nice to be filling up at the fuel pumps with the Elise and Exige next to each other. Man in the petrol station must have wondered what was going on.

[Stephen]

Check the starter earth. Mine was corroded where it was bolted to the chassis and threw up the same problem. all sorted now.

[robin]

Just to summarise:

It has started every time you have hot wired it at the starter.

It sometimes doesn't start on the key, but you do hear a click as you turn the key from run -> start (and a corresponding click when you let go of the key).

In that case you're looking at either the MFRU or a wiring fault. Not the starter or its solenoid.

Cheers,
Robin

[Stephen]

Mine clicked as above and started better when cold. When the car was hot the fault got worse for some reason. Strange as the bad earth should have been reasonably consistent.

[jammacdo]

Robin

Not exactly. Its started fine with the key since the other day when the fault occurred and enabled me to test the hot-wire to prove the starter motor worked. Its been "fixed" since then. Seems to be worse after the car has been sitting for a couple of days which makes me think the solenoid is sticky.

Could these symptoms still be the MFCU?

I guess its either £130odd for a starter or £70 for the MFCU. Or £0 if I clean the contacts - which I will do.

cheers

[robin]

Change nothing until it next won't start.

Then hotwire it.

If, even when hot-wired, the starter just goes clonk but doesn't turn, then you could be looking at a new starter (whole thing) or an earthing problem.

If, when hot-wired, the starter turns then you're looking at the MFRU IMHO.

Cheers,
Robin

[robin]

Usually the MFRU is very reliable unless it hasn't been mounted correctly - it's a sealed unit - if you crack open the seal you might make it work, but the inevitable moisture ingress will kill it soon enough. If it's not mounted properly it clunks around the engine bay until it cracks open, moisture gets in, it fails. Cleaning relay contacts is usually only a temporary measure. Most relays I have seen use a hard surface finish on the contacts (e.g. gold or nickel); once that's eroded the underlying metal is soft and will pit rapidly when used under load.

Cheers,
Robin