Post Gearbox change - this will shock you!

[LeeT5]

daft question but whats the condition of your battery. is it good. once a battery loses it ability to hold enough charge it can cause all kinds of probs. try getting a mate to connect some jump leads to your battery and try that, also have a look at the positive terminal under the bonnet. i think its on the passanger side

Yes it is a daft question!

If the engine cranks ok, without petering out within 15 seconds then i can already confirm, it has nothing to do with the battery. Applying jump leads will make no difference.

I agree with the mechanic about maybe a possible earth fault. However, its very easy to get misled. Start with the basics as 9 out of 10 times its nearly always something simple.

Battery voltage above 12.5v before crank. If below 12.2v then you need to charge and test! Any battery showing voltage below 12.2v is technically Discharged.
If engine cranks ok, check for rpm signal. Should be 200-300rpm on 'live readings' when cranking.
If you have an rpm signal then one must assume (at this point that you have a spark, switching at the injectors and 4-6amps draw on the fuel pump circuit.
you must also have 12v at the MAF and also 5v at the MAF.
(If any of these are not present, then the car will never start!!)

12v means that the main relay is powered up and live and 5v means that the CEM/ECM are live and powered up.

A bad earth will give you sporadic faults and intermittent symptoms - but they will be easily identifiable on AUTODATA. It will list the Earth points on your car and thus, your mechanic bloke should be able to check resistance at each one. Any voltdrop above 0.5v will indicate a bad earth and a potential problem.
Undo said earth point, derust, wirebrush and electro lube it, then retighten.

then check if the car starts again.

If your mechanic is worth his salt, then he'll know all this anyway.

[JamesT5]

daft question but whats the condition of your battery. is it good. once a battery loses it ability to hold enough charge it can cause all kinds of probs. try getting a mate to connect some jump leads to your battery and try that, also have a look at the positive terminal under the bonnet. i think its on the passanger side

Battery is fine, only 12 months old with a 3 year warranty. Besides, if the battery was knackered it wouldn't even try and start because there would be nothing to power the starter motor.

[graemewelch]

Battery is fine, only 12 months old with a 3 year warranty. Besides, if the battery was knackered it wouldn't even try and start because there would be nothing to power the starter motor.

i meant was it not supplying enough amps. was only a suggestion.

[graemewelch]

Yes it is a daft question!

If the engine cranks ok, without petering out within 15 seconds then i can already confirm, it has nothing to do with the battery. Applying jump leads will make no difference.

I agree with the mechanic about maybe a possible earth fault. However, its very easy to get misled. Start with the basics as 9 out of 10 times its nearly always something simple.

Battery voltage above 12.5v before crank. If below 12.2v then you need to charge and test! Any battery showing voltage below 12.2v is technically Discharged.
If engine cranks ok, check for rpm signal. Should be 200-300rpm on 'live readings' when cranking.
If you have an rpm signal then one must assume (at this point that you have a spark, switching at the injectors and 4-6amps draw on the fuel pump circuit.
you must also have 12v at the MAF and also 5v at the MAF.
(If any of these are not present, then the car will never start!!)

12v means that the main relay is powered up and live and 5v means that the CEM/ECM are live and powered up.

A bad earth will give you sporadic faults and intermittent symptoms - but they will be easily identifiable on AUTODATA. It will list the Earth points on your car and thus, your mechanic bloke should be able to check resistance at each one. Any voltdrop above 0.5v will indicate a bad earth and a potential problem.
Undo said earth point, derust, wirebrush and electro lube it, then retighten.

then check if the car starts again.

If your mechanic is worth his salt, then he'll know all this anyway.

i love your answers lee. least you get a proper reply to why im wrong and not a daft reply

[jardon]

Basically the starter motor runs, the engine just makes that turning over noise (like you get with the 'Start Prevented' situation), and the RPM needle spikes to 4K or 3K or whatever it wants to now and again.

I've been back to see the owner of the garage today and he seems to think it's electrical interference or some sort of earthing issue. He's booked me back in for the 2nd of September (that's the earliest I could get the car to him) and he said he'll go right through the car with Vida again and do some tests to establish the cause of the issue.

Although the job was a balls up, I'll be fair to the guy and give him credit where it's due and say he has made a decent attempt to put the problems right and forked out a 3 figure sum for replacement parts at his expense. Then there's the extra labour he's had to pay out and there's more to come a week on Monday. His guys may have made a hash of the job initially (and yes I'm annoyed at that), but he has and is doing his best so far to fix it.

Starter motor. It's drawing to much current on cranking which means the ECU thinks there is an electrical fault - always throws a crank position code and sends the rev counter all over the place as the crank sensor churns out spurious data. It may sound ok on cranking but mine was identical and there are plenty of others with the same issue. DiCE helped me diagnose mine as I could plot the (brand new) battery voltage as it fell to ~7 volts on cranking due to starter motor failing. It shouldn't get anywhere near that low. I may have a good spare starter if you'd like to try it out.

OR, nasty voltage drop in the starter circuit. http://www.aa1car.com/library/voltage_drop_testing.htm

My money is on the starter motor failing though. http://forums.t5d5.org/topic/19463-hard-hot-starting/

[Gold 'N' Brown]

Battery is fine, only 12 months old with a 3 year warranty. Besides, if the battery was knackered it wouldn't even try and start because there would be nothing to power the starter motor.

Please don't take this the wrong way (just some constructive criticism). Don't assume that that a 1 year old battery must be fine simply due to it's age. Nor does the 3 year warranty mean anything, except obviously the fact that you can get it replaced if it fails within that time. Your answer above implies that you've made an assumption that the battery is fine based on it's age.

Given the amount of problems you've had with the car, and a possible tendency to jump to conclusions, then I would encourage you to check things thoroughly and logically and not to make assumptions. It's the only way. Don't get me wrong, I'm not suggesting for one moment that you may have a problem with your battery, I'm merely interpreting from you reply above that you may be making assumptions about other factors rather than validating the symptoms and checking things off the list.

Apart from that, hat's off to you for sticking with it, working through a lot of these things yourself, and good luck getting it sorted

[silverhorse]

Starter motor. It's drawing to much current on cranking which means the ECU thinks there is an electrical fault - always throws a crank position code and sends the rev counter all over the place as the crank sensor churns out spurious data. It may sound ok on cranking but mine was identical and there are plenty of others with the same issue. DiCE helped me diagnose mine as I could plot the (brand new) battery voltage as it fell to ~7 volts on cranking due to starter motor failing. It shouldn't get anywhere near that low. I may have a good spare starter if you'd like to try it out.

OR, nasty voltage drop in the starter circuit. http://www.aa1car.com/library/voltage_drop_testing.htm

My money is on the starter motor failing though. http://forums.t5d5.org/topic/19463-hard-hot-starting/

Thats interesting and worth remembering for the time that it inevitably happens to me!! Cheers