Erratic tick over

vougese39 said:

so why is it a have a friend at jlr and they do the mapping and sensor design and dont use them?
as i have 14cux tester gen dealer kit, testbook, ids and sdd covers all bases and i have never diagnosyed wrong yet it is not a case of being serious it is a case of justifing cost as testbook has one i have never needed to use it yet and when at land rover, peugeot,citroen,rover,subaru,isuzu never need or was shown we needed to use one either very odd it is only the idy's that need this tool not the dealer i have worked at previously.

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I think the answer to that is quite simple,main dealers are still of the mentality of following fault codes and replacing parts - often at huge cost,which is why so many people call them "Stealers". Indies cant afford to do that as most of the time they are small enough that the customer deals direct with the tech who will work on the car.Fit a new £500 part and it doesnt fix the car - what then ? I'll tell you what happens,the indy loses out.
Can you honestly say you have never misdiagnosed a fault ? I cant,and I'm willing to admit it - but I do everything I can to make sure of my diagnosis.Just a single example,how do you diagnose TD5 driver demand faults ? Is it the pedal,the loom.plug or ecu ? With a scope you can tell in seconds if you know what to look for.When I first had T4 back in 2003 I really struggled with that exact fault,lost money on it etc.Now its easy with the scope and you can be 100% confident.
As an aside are you happy with T4,I remember you calling me to ask about it one day - do you wish you had bought Autologic instead ?

Edgie said:

Sometimes it ticks over just fine, then for no reason it virtually cuts out, then revs up then virtually cuts out etc etc etc..... what can it be?

3.9Efi RRC...

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I had a problem like that with my freelander,so did my dad with his mitsy pajero,both diesel,turned out to be the crankshaft sensor
I know nothing about v8's but I would check the crank shaft sensor.

to be honest Jon no after spending a whole year relearning what i was taught at land rover and having spent may hours using autologic on loan i think testbook for me is the better option!
was let down by omitech and the universal coms unit not a patch on ids or sdd i must be lucky never had a problem whatching the sensor reading and finding the fault yes stealer have a bad rep but if the manurfacuters want to cut warranty bills would they push for a scope? instaed of a diagnostic based plat form with a universal code reader?

as i was taught all though my training it is a code to help on a path to finding a fault. not this is the fault as many indy and dealers still belive this is the fault code this is the cause!
having done many diagnostic courses over the years i feel pretty dam confident and will not be buying a scope untill they supass the diag machine of the manurfaurers

Stuart,you are missing the point - a scope is there to test circuits and components that the scanner has pointed you to.Its in no way a replacement for a scanner,just a tool to confirm or deny what is actually happening.For instance many of the jobs I do are for other garages where cars have failed emissions tests - esp v8 RR's and 1.8FL's.Often oxy sensors and cats have been replaced with no results as a result of fault codes being followed.On a v8 its easy enough to see on T4 if the oxy sensor is switching well enough to get Lambda.With a FL its not so easy as the output from the sensor is not a decent waveform at the best of times.
With a scope you can watch in live time the output from the sensor and see if its able to switch,to start with and if the output is good enough for the ecu to use.With garages using cheap parts I often end up using the old original parts - esp FL cats.
All along the fault was a poor plug lead,fouled plug,leaky manifold gasket,etc,etc.Seeing the HT waveforms can tell you loads about how an engine is running - in seconds you can check where the main problem is or if not then move on.
With TD5's using a current clamp to do an electronic compression test will confirm if its worth changing an EUI to cure a missfire.Without spannering at all,on defenders you dont even need to open the bonnet.
It is a shame that Omitec have not done more with the UCM,but the latest software issue has moved on alot.Damn good tool that needs more work.
BTW, Aston Martin and Maserati both spec a Pico scope for part of their dealers kit,it will become more common once techs get used to using them and realising the benefits of them.One thing I have not mentioned is being able to scope a known good car to see what a particular sensor should give.Save the waveform and then compare it to the faulty car.LRDTS told me to do this on a ZF box years ago because they knew I used a scope.... Also used that to work out that a Gems v8 had been fitted in a Thor car,it sometimes ran very badly,sometimes fine.Always showed a cam sensor fault,yet its waveform was fine.Then I scoped another Thor engine and found a very different square wave.The Gems sprocket has totally different spokes to the Thor.How else could you diagnose that ?

Im with jon on this one - a scope is a great tool. not used them since physics at school and couldnt figure it out properly then, but i think it would be invaluable for proper diagnostics.

cheers

Sounds like a scope is a good idea if like you say you are doing the left overs from a garages **** up/ no repair?

im not missing the point it is more a case of horses for courses.
unlike most the day i use one you will be the first to know