Sunday, 24 September 2017

vvt pulleys

be very wary of garages wanting to charge you with replacing one of these

Monday, 11 September 2017

Saturday, 2 September 2017

What is a car

Its the engine is misbehaving then  the entire car feels ill disiplined and out of kilter.
Doesnt change gear properly,you end up fighting it rather driving it

Wednesday, 30 August 2017

Airflow sensors

The amount of air entering your engine is a  mesaurable value.
This  undertaken either by a moving vane air sensor or more commonly a MAF or mass airflow unit.
The early MAFs were literally a  heated wire,the amount of air  was detected by the level of current needed to maintain the wires temperature.
All a bit hit and miss and prone to a lot of failures. Todays MAFs use thin film technology giving far quicker responses to changing air flow conditions

Monday, 28 August 2017

Graphs and information

Pulling data and information from a car is useless without being able to apply the information

Saturday, 26 August 2017

The ECU isnt that smart

Your engines control unit or brain a some cal it isn't really smart.
It simply reacts to inputs and works on the basis they are correct nothing more

Thursday, 24 August 2017

Full basic health check

how well is your engine running?
good bad,hard to start either hot or cold.
Starting issues are often the sign of  deeper issues developing,way before your engine  fault light appears.In  fact it may never illuminate and still the car will strand you.

A basic check is via the exhaust using a pulse sensor,and no bonnet lifting even needed 

Wednesday, 23 August 2017

Coil on plugs

These are way better than traditional caps and spark plug leads but,the continuous heat soak buried in the engine takes its toll on them.
Cheap ones are the worst culprits,and they can fail without warning
we recommend replacement of them all at 30 000 miles to avoid that

Sunday, 20 August 2017

Snap secondary testing

In a steady state engine running condition the ecu assumes full control.
A snap test  allows issues with certain components to reveal them selves.
As a subject its advanced and powerful one we will be entering in much more detail

Sunday, 13 August 2017


some car running issues  fight a hard battle to find,

Thursday, 3 August 2017

fuel filters

Fuel filters are a vital part for regular maintenance.
A clogged or partially clogged  wil put a lot of strain on your fuel pimp causing it to fail.
for a few pounds it is false economy not to simply replace it .....dont skimp

Sunday, 30 July 2017

The classic secondary ignition waveform

There is a lot of power diagnostics wise located in this  old art but it takes time and effort to learn

Thursday, 27 July 2017

Run it tills it drops

Al well and good  from the point of view of running a car.NOt if it  breaks down in the middle of nowhere.
Even the best maintained car can and will  fail at some point,good maintenance wil make it far les likely

Tuesday, 25 July 2017

fuel caps and evap

Todays engine  have fuel tanks that vent  back into the engine itself rather than to atmosphere.
In earlier day the vent was simply hung out of the fuel tank  to equalise pressure.
vehicles today  have a closed system that  partly  absorbs metro; vapour and balances atmospheric pressure  through a charcoal canister.
The amount of gases  or vapour drawn through the  canister is dependant on  many things obviously balancing atmospheric  pressure with out  overichening fuel mixture.
Blocked charcoal canisters and leaky pipes or non operative  evap valves are the common failures.
Any issue with the evap can cause issue with engine power and need looking at.
If when you release your fuel cap there is a n intake of air  you definately have issues even without a code or light appearing

Monday, 24 July 2017

Lunar autos methods

Here at the workshop  a car arrives,usually with issues that other garages have long given up on.Not to say they cant fix it but its simply not worth their while  pushing any further work.
In some cases a recalcitrant issue does  end up in the scrap yard before its time.
All  engine running issues,take time to pin down,its rarely  the same day  find it and fix it that isnt the real world.

Sunday, 16 July 2017


sometimes hard to detect but never ignore them big killer of engine power

Friday, 7 July 2017

No codes

No codes!
Actually no codes is the usual case  of many or in many driveability issues.
Live date is mostly the first port of call then  other non intrusive particular relative compression testing.
Its a simple but powerful test of an engines compression needing no dismantling of anything save  stopping the engine starting

Tuesday, 2 May 2017

An engines changes in power output

Misfires:are a great killer of power.
These can be mechanical,fuel related,ignition related what ever their cause they need to be detected and rectified.
Using a maths channel is a superb way to do just this

Sunday, 23 April 2017


never presume the same symptoms in the same car are down to the  same issue

Thursday, 13 April 2017

exhaust pulse test

A quick powerfull method of checking engine integrity and running state

Cost £45

Sunday, 9 April 2017

Rusty fuel tanks

A nice jag that has been stood for a long time was suffering from lack of fuel and avery noisy pump cause rust clogged fuel system

Tuesday, 4 April 2017

connecting an oscilloscope

Remember an oscilloscope is measuring voltage making the possibility of shorts a ll to  possible.
So common sense prevails

Sunday, 2 April 2017

Saturday, 1 April 2017

Injector cleaning fluids

D o injector cleaners work?in theory into the tank and your good.
No dont waste your money.
Only injector removal and ultrasonic cleaning actually works.We carry out this service so please enquire

Thursday, 30 March 2017

fuel injectors

they are basically pretty simple devices,but very well engineered.
2 thousands of a second is the typical opening time.A solenoid that can open close in such a time period is a very accurate piece of engineering and they go wrong very easily

Monday, 27 March 2017

running a car

its an expensive  game,but spend a little to avoid big bills

Sunday, 26 March 2017

collapsed CAT

A catalytic converter is a very reliable item but  they can collapse causing some major issues a quick of engine vacuum is a sure fire way of checking

Wednesday, 22 March 2017

thermal imaging

Our flir thermal camera is now one of mainstay tools for tracking  certain faults especially good for  looking at exhaust manifold branches for misfire detection

Sunday, 26 February 2017

A collection of scopes

Diagnosing modern engines without an oscilloscopes really is a  waste of time
Here at lunar we have an ever growing collection.NO1 among them is without doubt the pico

Wednesday, 22 February 2017

Its all in the exhaust

Your exhaust seems to be nice constant stream,seems to be.In fact there are  rises and falls in that  apparently constant stream
How do you detect them?
You need a signal generator and an oscilloscope which can detect very short time periods,ie 2 milliseconds,it a great diagnostic tool without  even lifting the bonnet.