18SV non-starter [Resolved]

[MrSteve]

Hi all

My 1990 1.8L has decided it no longer wants to move...

It had been running fine since I got it in May, and I've gradually been getting it ready for the MOT since.

Engine turns over, but there is no spark on the entire HT side (have done the inductive strobe light test on HT leads plus the old earthing the HT lead to block method.

At the LT connector at the coil there is 12v, but the Haynes advice to connect a bulb across the terminals to check if it flashes when turning over produced nothing.

Battery resting voltage is 13.1v-ish, dropping to around 10.5v when cranking. Was charging at around 14.3v...back when it ran...!

The crank sensor seems to be fine- I did replace it, but only because the outer rubber of the lead was crumbling away with age- it drove fine with the new one and refitting the old one made no difference to lack of starting.

No fault codes show on the paperclip test- just endless 1-2 flashes.

No fuses have blown.

There is fuel getting through the pump to the carb and the fuel cut-off solenoid clicks when you switch the ignition on.

A new coil and Valeo ignition amplifier have made no difference (though I know you can't rule something new being faulty too!).

Earth strap from gearbox to engine is sound.

I had a look at the MSTS unit- the pins are all straight and inside nothing looks burnt-out and there is continuity between the big connector and the coil.

Maybe the MSTS unit has died, as this the only thing I can't test.

Has anyone got any ideas

Thanks

[Cavalier342]

Hi, I'm not sure what MSTS is, but did you check the distributor cap? Remove it and check inside for worn out contacts and the rotor arm as well.

[MrSteve]

Cap, rotor arm, plugs and leads are virtually new so unworn- done within the last 6 months and have only done a couple of hundred miles if that.

MSTS unit is the black box on the bulkhead that deals with the ignition timing.

[James McGrath]

Cap, rotor arm, plugs and leads are virtually new so unworn- done within the last 6 months and have only done a couple of hundred miles if that.

MSTS unit is the black box on the bulkhead that deals with the ignition timing.

I've had problems starting before after a long period of non use due to condensation accumulating inside the distributor cap.
If you haven't already just take the cap off and clean it out, even if it's not that old.

[MrSteve]

I checked the distributor earlier today. It is dry, but I am not sure if there should be burn marks like this on the contacts:


I gave those and the rotor arm a clean up with some fine grade wet and dry- back to shiny metal.

After a lot of fiddling the car started up (eventually) this afternoon.

[Robsey]

Good to see it is a nice easy fix.
Hopefully it will behave itself for the rest of the year.

[MrSteve]

Spoke too soon- it's dead again- cranking over and no sign of life.

[Robsey]

Sounds like time to go back to basics.

Test for a spark at the plugs.
Hopefully to check that the coil, leads, amplifier, distributor hall-effect sensor or crank angle sensor are all okay and working.

Test for fuel entering the engine / Carburettor.
To check / rule out a problem with fuel supply. Pump, blocked jet, fuel cut-off solenoid or float height.

[MrSteve]

I refitted the battery after charging it up last night and the car started- though now idling badly and dying.

As the mot was booked for today, all I could do was whip off the plastic air intake and spray carb cleaner through all visible carb orifices. I had done this before, but clearly some dirt has moved through the carb now. It did seem to work as the idle smoothed out.

Took it for an italian tune-up on the local bypass and braked heavily lots to scuff off the surface rust on the discs.

Cav is now at the garage having its mot.

Fingers are crossed!

[Envoy CDX]

Did it pass?

[MrSteve]

It did- and with no advisories.

Unfortunately, it's dead again though.

[Envoy CDX]

Damn it
What's it like on crank over? Slow, fast?

[MrSteve]

Somewhere in the middle- with a freshly charged battery it spins fairly quickly initially then gradually gets slower until you run out of electricity.

The starter doesn't spin the engine over as fast as the new starter on my other car, for instance, and it is probably the original unit.

[Robsey]

Are we thinking,

A - Weak battery. Discharges very quickly.?
B - Dirty or loose wiring to starter.?
C - Worn starter?

I think this is definitely separate to the non-start issue.
Yet another re-check of all wiring to the coil, msts unit, carburretor, amplifier etc.

[cavalier1990]

Have you checked for a drain on the battery, like a boot light stuck on? Also is battery readings about 13.5 - 14 v when ticking over, if lower alternator might be kapoot or diode pack gone. Check for AC voltage readings at battery.