cold start problem - first start only

[greenink]

Hi, only had the Chim 6 months, so been listening and learning! Sorry to post a 'negative' thread when there are so many fantastic things about the car!

It now won't start from cold (pump primes, turns over, but not a 'squeak' from any of the cylinders), but if I pop the clips on the distributor cap and 'fiddle around' inside the distributor it starts straight away. Once it's started it's fine for about 4 - 5 hours and will start immediately. Leave it overnight, or during the day at work, and it bl**dy does it again! It had a similar fault before but that was only once every couple of weeks. Once it's going it runs like a dream, and is a joy to drive (no idling problems at all). Once started I can switch off immediately, and it will re-start no problem.

The plugs and leads were replaced at the last service, and since then I've replaced the distributor cap and rotor arm as I was convinced it was them at fault. I've even sealed up with that sealent spray in case it's damp getting into the lead ends or dizzy (could it be somewhere else?). Using a bit of accelerator on starting doesn't help either (in case of a sticky stepper motor). The Bible Mk1 mentions a cold start injector, but then says current cars don't have it. Mines a late 96 4 litre, is that current enough! The only other thing is that there is a slight amount of 'play' in the rotor arm spindle. Is this normal? Would it affect the timings somehow, and if so, why not every time it starts rather than just when it's been off for a while.

It's getting a bit embarassing with the bonnet up so often at work! Can anyone suggest anything? I could check for a good spark, but read somewhere that resting the plug on the engine block can mess with the electrics, what's the best way to do it safely?

Thanks in advance for any thoughts, I am starting to pull my hair out, as it's my only car, and is fantastic apart from this!

[plipton]

My rotor arm has a tiny amount of play so that's probably normal (and it starts every time - sorry to rub it in....)

Certainly sounds like no spark if the pump primes.

Not sure about the plug-out spark test although I can't see it would hurt if you hold the plug firmly against the head. Just don't run the motor for more than a second or so to avoid Cat damage.

Do you have an analogue multi meter? You might be able to wrap the leads around an HT lead and get enough induced voltage to get a reading. Long shot though.

How about the LT circuit? or the main HT lead from the coil? either of these being duff could cause this problem. Or what about the coil itself!! (they can cause some odd problems)

Good luck

Plipton

[Incorrigible]

Weak spark I reckon

Take the HT leads off end by end one by one, quick squirt of WD40, same with the plug extenders, clean the inside of the cap (again WD40)

That should cure it for a fortnight or so

[Incorrigible]

Forgot to say, what leads were used in the service? The standard rover ones break down very quickly due to the high under bonnet temps. Shouldn't be that fast though

[trefor]

I have the solution - you'll have to use the car every lunchtime. That way it never fails to start after work

When did the problem start? Before the service?

I'd check the leads too - and the plug extenders. If they look a bit knacked then replace them (get them from ACT - less than half the price of TVR/Vauxhall).

T/.

[shpub]

If it was a lead problem then I would expect some of the cylinders to fire... unless it was the lead from the coil.

There is also an ignition module and a couple of balast resistors in the vincinity and they could be intermittent as could the leads from the dizzy to the ignition module. Holding a spark plug against the plug with a metal clamp is fine- afterall it is screwed into the heads and needs that contact to work anyway.

[GreenV8S]

It's possible you have a duff HT lead shorting out somewhere, or a fault in the spark signal to the ECU, which you're accidentally fixing when you move the leads around to remove the cap. Have you tried wriggling the wiring without taking the cap off, to see if this does the trick?

If this doesn't help, I suggest you pop down your local motorfactors and buy a 'spark trace' light, this is a passive strobe light that connects in line in one of the HT leads and flashes each time that lead sees a spark. This would confirm whether the problem is spark or fuel. (If you can find one, also get a NOID light which does a similar thing for an injector.)

[greenink]

Thanks for the ideas.

The leads were from a certain 'garage' near Guildford, so I am sure they aren't the standard Rover ones. If they were breaking down I would have thought I would get lumpy running as well,a nd constant starting probelms, not just the first one. Ive WD40'd inside Dizzy and plug ends already, but not the extenders (will try that).

It had the problem intermittently before the service (part of the reason for the leads being changed), its just got worse over time.

I've tried the starting at night trick, and cant see any shorting from any of the leads at all, and as they are new that would be very surprising.

I'll definitely hunt down the spark trace light and NOID light, that should help narrow things down, plus a plug out spark test as well.

Thanks for the advice!