Dont over look your brakes

Ouch several cases lately of lousy engine power with their cause  lying in other areas  altogether  and nothing to do with the management   system
Its wise to  have your brakes checked regularly  to avoid a sticking brake all to easy for a caliper piston  to  stick and cause you some serious headaches

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125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

They get neglected

Ignition leads  or wires  as they are called in the US.
They perform a very stringent and tough job carrying high  voltage or  HT  from you  coil  or distributor.
Now here is  the rub  they may look OK  but,they will  fail gradually  so  simply replace them after say  15 000 miles.
One  nice neat test  for failing leads is to  wait until it goes dark  lift the bonnet start the engine  and let your  eyes  adapt.Any leaking  HT  will  stand out like a sore thumb,these leaks  will show  upon an oscilloscope  but it is a  free  method  of checking.Any signs of  arcing then replace  all of them.

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125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

Lets be honest

Your typical garage will fit  the cheapest   junk they can find to  your car,maximising profits is their main concern.
Well I'm not  saying they are all like that  far from it but it remains  that   making a  bit more on each service etc  is always tempting.
The motorist is the one who pays  ultimately.
filters  oil air  or fuel we  recommend one  manufacturer..........  wix

lunar auto diagnostics

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125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

A badly knackered manifold

Here we are a  replacement  inlet manifold  after the old  one was found to be  cracked in numerous places etc ie air leaks

lunar auto diagnostics

Full range of engine fault diagnostic services Contact us for help

125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

air leaks

Hmm air leaks
Air leaks  can and wil  develop at the drop of a hat.
where do air leaks occur?inlet manifold  to head is the favourite and the biggest to fix.Vacuum hoses are another  especially when  these age and  soften
Brake servo  air leaks  and  evap system air leaks.
So what is the best way of detecting them?Several really  a  mixture  of  smoke  ddetection  carb cleaner spraying and  fuel  trim numbers.
A  high positive fuel trim  that improves with revs is a good sign,but all these methods need  drawing ito a single point to be  really effective.
Your ecu can   corret  only so far  with an air leak  and it will then give up and set an error code

 

lunar auto diagnostics

Full range of engine fault diagnostic services Contact us for help

125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

power delivery

Your engine  performs a very    central role.
What do we  mean?
Simple you control the engine through the throttle,accelerating  sudden accelerating.If that  lump of metal or the engine  starts to develop  faults  its  power delivery will  do one thing fall.
How  slight an error  does it taske  to  cause  power  loss  answer  very slight.
a worn spark plug,a sensor not behaving exactly as it should  will   clobber  power,the problem is you adapt to it  slowly  but inevitably until if you don't  sort it the car will stop

lunar auto diagnostics

Full range of engine fault diagnostic services Contact us for help

125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

error corrections

Your cars  brain  will  correct for a  lot of errors but  after a while  it will fall over and give  you an headache.
The simplest fault  would be an airleak  caused by a failing  inlet manifold   gasket
The excess  air wil cause  your brain to  add more fuel  to compensate and do a  very  good  job  but only up to a  point ie  if the leak  gets worse  then it  fail  and  set a code or in other words turn on the engine light
Our  live data  check would show  this  up well before  it caused any issues so saving you a lot of headaches

lunar auto diagnostics

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125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

The downstream o2 sensor

An oxygen sensor placed after  the cat  on  certain  cars  is a verification of the   the cats  performance
Their  voltage reading  if everything is  normal  will be  stable  around  .4  volts
If they do set a po136  code then  its  more  than likely  the sensor at fault not the wiring  but of course it can be just that

lunar auto diagnostics

Full range of engine fault diagnostic services Contact us for help

125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

The oxygen sensor

THe oxygen sensor installed  in your car  can also be used  to  check for the correct mixture  on  on standard  cars  ie non fuel injection.
Its  not a method widely used but if  your  engine  as  everything in agreement the sensor  will .4  volts  at  14:1  air fuel ratio and  the readings  can used  to  see what the mixture is  ie  .9  would be to rich etc

lunar auto diagnostics

Full range of engine fault diagnostic services Contact us for help

125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

An injector waveform

Well here is a  waveform of a fuel injector
THis  captured  using a good old  crt  scope  so  if you want to  go the hog  and get into  diagnostics,get your self over to ebay and  buy  a  unit  with a bandwidth of at least  20mhz.After that  just swot up  on  using a scope  the biggest   aspect  to get right is  trigger settings.
Remeber using a scope  is old school  and can  pinpoint faults  but it needs  experience and understaing
You tube is the best place to  head to for  videos  on  engine diagnostics  and  search for scanner danner  who  is one of the best in the diagnostics  business  over in the states

lunar auto diagnostics

Full range of engine fault diagnostic services Contact us for help

125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

coil packs

Strije out the  oscilloscope and capyure the  waveforms  of all  the   packs  for a full inspection.
As can be seen here  these  pictures  reveal  two that are  failing

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125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

Bosch

THis was  thre name on all injection systems  when  the system became   widespread.
Bosch everything  and  everybody else could go phooey
Other  manufacturers  soon got  their  own systems  up and running.Siemens  being one such,all  renault  use  them with  no bosch  in site

lunar auto diagnostics

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125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

The evap system

If you can  whiff  petrol  coming from your car  then  this  can indicate  problems  with your evap  system  developing  privlewms.
Dont ignore it  it can cost  you money if it develops

lunar auto diagnostics

Full range of engine fault diagnostic services Contact us for help

125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

Its all in the waveform

Here is  an injector waveform  from  a  1.6  renault  engine.
The   engine  is  idling  badly withg  45  fuel trims  short term all  pointing to  wrong  cam timing.
Okay so a  little  bit of cam timing   checking reveals  this to be the case.
These  engines dont  use keys  for the pulleys so its  cut outs  and crank pin tools  not the easiest of jobs to accomplish  so its  off with belt and  nudge everything back into alignment

lunar auto diagnostics

Full range of engine fault diagnostic services Contact us for help

125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

Idle conditions

An idling engine  tells  you a lot about the engines state  of running.
Take the time to  lift the bonnet  and listen and watch to what your engine is  doing.Does it  idle  in a stable state or does  it lope about.
Ideally the idle should be rock solid  with  very small variations.
Okay if the idle is  good  take it up the rev  range and see if the engine  is still   erant or  missing slightly
If your engine sits their  jumping around then yes  you have an issue,could simply  be a  duff air  idle valve so  if  it misses or lopes further up the rev range  you have an issue with the whole    system management etc

lunar auto diagnostics

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125,east bawtry road
Rotherham
south Yorkshire
s60 4lq

A typical fuel rail and its injectors

The most accurate piece of engineering in your engine is the injector
2 microns  means they are very susceptible  to dirt  being passed from  your  fuel filter ie  if its  not changed at regual intervals
fuel filters are  cheap but injectors aren't  so  double  check the filter as been replaced   on the date set

lunar auto diagnostics

Full range of engine fault diagnostic services Contact us for help

125,east bawtry road
Rotherham
south Yorkshire
s60 4lq