TROUBLESHOOTING GUIDE
INTRODUCTION PETROL - POOR EMISSION READINGS PETROL - POOR PERFORMANCE / ECONOMY PETROL - PINKING/DETONATION/PRE-IGNITION/RUNNING ON DIESEL - POOR EMISSION READINGS DIESEL - POOR PERFORMANCE/ECONOMY   TESTS and DIAGNOSIS PROCEDURES and  RECOMMENDED RECTIFICATION ACTION IF YOU KNOW WHICH SECTION YOU WISH TO GO TO CLICK THE LINK BELOW. OTHERWISE PROCEED TO THE INTRODUCTION 2-1-1 Unit Application and Installation Summary 2-1-2 Post Installation Summary - General 2-1-3 Post Installation Summary - Petrol 2-1-4 Post Installation Summary - Diesel 2-2-1 Ignition System  - Mechanical Advance Curve Test Procedure 2-2-2 Ignition System - Vacuum  Advance Curve Test Procedure. (Using a Mityvac vacuum hand pump) 2-2-3 Ignition System  - Vacuum Advance Curve Test Procedure. (Without using a Mityvac Hand Vacuum Pump) 2-2-4 Spark Plug grade and gap 2-3-1 Air Cleaner Test Diagnosis 2-4-1 Carburettor Choke/Cold Start Device Test Diagnosis 2-4-2 Carburettor Operation Test Diagnosis 2-4-3 Fuel Injection System Cold Start Device Test Diagnosis 2-4-4 Fuel Injection System Test Diagnosis 2-4-5 Diesel Excess Fuel/Cold Start Device Test Diagnosis 2-4-6 Diesel Fuel Injection Equipment Test Diagnosis 2-5-1 Positive Crankcase Ventilation (PCV) System Test Diagnosis 2-5-2 Engine General Condition Test Diagnosis 2-6-1 Cylinder Bore and Piston Condition Test Diagnosis 2-6-2 Cylinder Head and Gasket Test Diagnosis 2-7-1 Auto vacuum Kickdown Diaphragm Test Diagnosis 2-8-1 Brake Binding Test Diagnosis 2-8-2 Clutch Slipping Test Diagnosis
	"In 99% of cases where customers have concerns after the installation of a Powerplus unit, the fault has been traced to be either the poor condition of the engine, associated ignition/fuel system components, or that the Powerplus unit has not been fitted in accordance with the installation instructions. Therefore refer to the installation instructions and check the engine/fuel and ignition systems FIRST. The other 1% has been found to be where adjustments have not been carried out as detailed in the post installation instructions".
	POWERPLUS FAULT FINDING GUIDE
	INTRODUCTION  This guide has been compiled to assist with the diagnosis and rectification of any post Powerplus unit installation. In the event of any concern being referred to Powerplus Technical Department, this guide will be the basis of establishing the cause of the customer's reported concern. It is therefore of paramount importance to ensure you have carried out all of the relevant diagnosis procedures and recommended rectification before contacting Powerplus Technical Department. Ensure that any readings/results are recorded, as these are necessary before any technical support can be given.
	HOW TO USE THIS FAULT FINDING GUIDE
	This Fault Finding Guide is divided into two sections. SECTION 1 and SECTION 2. SECTION 1 This section relates to the symptom(s) or concern(s) reported by the customer and the possible causes. This section is further divided into two parts, PART A and PART B. PART A refers to Petrol Engines. and PART B refers to Diesel Engines. SECTION 2 This section relates to the test and diagnosis procedures and the rectification action recommended in order that the customer's concern(s) can be resolved. SECTION 1 and SECTION 2 are inter-related by cross references being made in SECTION 1 to specific test and diagnostic procedures and the subsequent recommended rectification action detailed in SECTION 2. Wherever the test and diagnosis procedure states that readings should be recorded, please ensure that this is done as they will be referred to in the event of Powerplus Technical Department being contacted for further assistance.
	SECTION 1
PETROL	SYMPTOMS and CAUSES PART A - PETROL ENGINES SYMPTOM - POOR EMISSION READINGS. POSSIBLE CAUSES. (Assuming that the engine oil is not over the maximum level.):- Incorrect size unit fitted - Refer to SECTION 2-1-1. Unit not installed correctly - Refer to SECTION 2-1-1. Post Installation engine oil and oil filter change not carried out - refer to SECTION 2-1-2. Initial ignition timing not set to the correct specification - Refer to SECTION 2-1-3. Mechanical advance curve not to specification - Refer to SECTION 2-2-1. Vacuum advance curve not to specification - Refer to SECTIONS  2-2-2 & 2-2-3. Incorrect type of spark plug grade fitted - Refer to SECTION 2-2-4. Incorrect spark plug gaps - Refer to SECTION 2-2-4. Air filter element dirty - Refer to SECTION 2-3-1. Air filter flap set to incorrect position - Refer to SECTION 2-3-1. Thermal air filter flap not functioning correctly - Refer to SECTION 2-3-1. Carburettor cold start device inoperative - Refer to SECTION 2-4-1. Carburettor cold start device not set to manufacturer's specifications - Refer to SECTION 2-4-1. Carburettor idle mixture not set to lowest CO without misfire - Refer to SECTION 2-1-3. Carburettor not functioning correctly - Refer to SECTION 2-4-2. Fuel injection cold start device inoperative - Refer to SECTION 2-4-3. Fuel injection cold start device not to manufacturer's specifications - Refer to SECTION 2-4-3. Fuel injection idle mixture not set to lowest CO without misfire - Refer to SECTION 2-1-3. Fuel injection system not functioning correctly - Refer to SECTION 2-4-4. PCV system malfunctioning - Refer to SECTION 2-5-1. Valve stem oil seals worn - Refer to SECTION 2-5-2. Excessive blow-by - Refer to SECTION 2-6-1. Blown head gasket - Refer to SECTION 2-6-2. Automatic gearbox vacuum kick down diaphragm perforated/split - Refer to SECTION 2-7-1.
PETROL	SYMPTOMS and CAUSES PART A - PETROLENGINES SYMPTOM -POOR PERFORMANCE/ECONOMY. POSSIBLE CAUSES :- Incorrect size unit fitted - Refer to SECTION 2-1-1. Unit not installed correctly - Refer to SECTION 2-1-1. Post Installation engine oil and oil filter change not carried out - refer to SECTION 2-1-2. Initial ignition timing not set to the correct specification - Refer to SECTION 2-1-3. Mechanical advance curve not to specification - Refer to SECTION 2-2-1. Vacuum advance curve not to specification - Refer to SECTIONS 2-2-2 & 2-2-3. Incorrect type of spark plug grade fitted - Refer to SECTION 2-2-4. Incorrect spark plug gaps - Refer to SECTION 2-2-4. Air filter element dirty - Refer to SECTION 2-3-1. Air filter flap set to incorrect position - Refer to SECTION 2-3-1 Thermal air filter flap not functioning correctly - Refer to SECTION 2-3-1. Carburettor cold start device inoperative - Refer to SECTION 2-4-1. Carburettor cold start device not set to manufacturer's specifications - Refer to SECTION 2-4-1. Carburettor idle mixture not set to lowest CO without misfire - Refer to SECTION 2-1-3. Carburettor not functioning correctly - Refer to SECTION 2-4-2. Fuel injection cold start device inoperative - Refer to SECTION 2-4-3. Fuel injection cold start device not to manufacturer's specifications - Refer to SECTION 2-4-3. Fuel injection idle mixture not set to lowest CO without misfire - Refer to SECTION 2-1-3. Fuel injection system not functioning correctly - Refer to SECTION 2-4-4. PCV system malfunctioning - Refer to SECTION 2-5-1. Valve stem oil seals worn - Refer to SECTION 2-5-2. Excessive blow-by - Refer to SECTION 2-6-1. Blown head gasket - Refer to SECTION 2-6-2. Automatic gearbox vacuum kick down diaphragm perforated/split - Refer to SECTION 2-7-1. Brakes Binding - Refer to SECTION 2-8-1. Clutch slipping - Refer to SECTION 2-8-2.
PETROL	SYMPTOMS and CAUSES PART A - PETROL ENGINES (continued) SYMPTOM -PINKING/DETONATION/PRE-IGNITION/RUNNING ON. POSSIBLE CAUSES :- Incorrect size unit fitted - Refer SECTION 2-1-1. Unit not installed correctly - Refer to SECTION 2-1-1. Post Installation engine oil and oil filter change not carried out - refer to SECTION 2-1-2. Initial ignition timing not set to the correct specification - Refer to SECTION 2-1-3. Mechanical advance curve not to specification - Refer to SECTION 2-2-1. Vacuum advance curve not to specification - Refer to SECTIONS 2-2-2 &  2-2-3. Incorrect type of spark plug grade fitted - Refer to SECTION 2-2-4. Incorrect spark plug gaps - Refer to SECTION 2-2-4. PCV system malfunctioning - Refer to SECTION 2-5-1. Valve stem oil seals worn - Refer to SECTION 2-5-2. Excessive blow-by - Refer to SECTION 2-6-1. Blown head gasket - Refer to SECTION 2-6-2. Automatic gearbox vacuum kick down diaphragm perforated/split - Refer to SECTION 2-7-1.
DIESEL	SYMPTOMS and CAUSES PART B - DIESEL ENGINES SYMPTOM - POOR EMISSION READINGS. POSSIBLE CAUSES. (Assuming that the engine oil is not over the maximum level.) :- Incorrect size unit fitted - Refer to SECTION 2-1-1. Unit not installed correctly - Refer to SECTION 2-1-1. Air in Unit - Refer to SECTION 2-1-1. Post Installation engine oil and oil filter change not carried out - Refer to SECTION 2-1-2. Fuel filters dirty - Refer to SECTION 2-1-2. Maximum no load speed not reset as per post installation instructions - Refer to SECTION 2-1-4. Air filter element dirty - Refer to SECTION 2-3-1. Excess fuel cold start device inoperative - Refer to SECTION 2-4-5.  Spill timing not set to the correct specification - Refer to SECTION 2-4-6. Incorrect type of Injector(s) fitted - Refer to SECTION 2-4-6. Injector(s) spray pattern incorrect - refer to SECTION 2-4-6. Injector nozzle(s) dirty - Refer to SECTION 2-4-6. Injector(s) break pressure incorrect - Refer to SECTION 2-4-6. Governor advance curve not to specification - Refer to SECTION 2-4-6. Injection Pump Calibration not to specification - Refer to SECTION 2-4-6. Valve stem oil seals worn - Refer to SECTION 2-5-2. Excessive blow-by - Refer to SECTION 2-6-1. Blown head gasket - Refer to SECTION 2-6-2. Automatic gearbox vacuum kick down diaphragm perforated/split - Refer to SECTION 2-7-1.
DIESEL	SYMPTOMS and CAUSES PART B - DIESEL ENGINES SYMPTOM -POOR PERFORMANCE/ECONOMY. POSSIBLE CAUSES. (Assuming that the engine oil is not over the maximum level.) :- Incorrect size unit fitted - Refer to SECTION 2-1-1. Unit not installed correctly - Refer to SECTION 2-1-1. Air in Unit - Refer to SECTION 2-1-1. Post Installation engine oil and oil filter change not carried out - Refer to SECTION 2-1-2. Fuel filters dirty - Refer to SECTION 2-1-2. Maximum no load speed not reset as per post installation instructions - Refer to SECTION 2-1-4. Air filter element dirty - Refer to SECTION 2-3-1. Excess fuel cold start device inoperative - Refer to SECTION 2-4-5.  Spill timing not set to the correct specification - Refer to SECTION 2-4-6. Incorrect type of Injector(s) fitted - Refer to SECTION 2-4-6. Injector(s) spray pattern incorrect - refer to SECTION 2-4-6. Injector nozzle(s) dirty - Refer to SECTION 2-4-6. Injector(s) break pressure incorrect - Refer to SECTION 2-4-6. Governor advance curve not to specification - Refer to SECTION 2-4-6. Injection Pump Calibration not to specification - Refer to SECTION 2-4-6. Valve stem oil seals worn - Refer to SECTION 2-5-2. Excessive blow-by - Refer to SECTION 2-6-1. Blown head gasket - Refer to SECTION 2-6-2. Automatic gearbox vacuum kick down diaphragm perforated/split - Refer to SECTION 2-7-1. Brakes binding - Refer to SECTION 2-8- 1. Clutch Slipping - Refer to SECTION 2-8-2.
	SECTION 2
	TESTS and DIAGNOSIS PROCEDURES and  RECOMMENDED RECTIFICATION ACTION
2-1-1	Unit Application and Installation Summary
	(a) Ensure that the correct unit for the engine type and capacity is fitted. refer to the Powerplus Application Guide. If the wrong unit is fitted remove it and fit the correct one in accordance with the Powerplus Installation Instructions. A summary of which follows :- (b) to (g). (b) Ensure that the Powerplus unit is fitted into the supply line and NOT the return line. (c) Ensure that the Powerplus  unit is not mounted above the highest point of the fuel system; (this also applies to fuel hose runs to and from the Powerplus unit). (d) Ensure that the shortest length of fuel hose from the fuel outlet of the Powerplus unit is used. (e) Ensure that the Powerplus  unit is fitted securely in a location where it receives road/engine vibrations. (f) Ensure that there are no tight bends in the pipe work to and from the Powerplus unit that could restrict fuel flow; likewise ensure that pipe work to and from the Powerplus unit is not squashed between two surfaces or components that could restrict fuel flow. (g) Ensure that all air is expelled from the Powerplus unit by bleeding the   fuel system through, with the engine running and the unit well below the highest point of the fuel system. This of paramount importance with Diesel and LPG installations.
2-1-2	Post Installation Summary - General
	(a) Ensure the air cleaner element is clean. Renew if dirty or contaminated.  (b) Ensure fuel filters, if fitted, are clean and serviceable. Renew if dirty or contaminated. (c) After 1,500 miles (2,400Km), change engine oil and oil filter.
2-1-3	Post Installation Summary - Petrol
	(a) After initial installation, take vehicle on a road test for 5 miles (8Km), after which, tune the engine by setting the initial ignition advance to manufacturer's specification, after ensuring that c/b points are clean and set to correct gap/dwell angle. Adjust the idle mixture, (where possible), to the lowest CO reading without inducing a misfire. (b) After 1,500 miles (2,400Km) recheck ignition settings and idle CO reading, adjusting to the same criteria as detailed in (a) above.
2-1-4	Post Installation Summary - Diesel
	(a) After initial installation, take the vehicle on a 8 mile (8Km) road test, after which carry out a smoke emission test and check the maximum no load speed. Adjust, (where possible), the maximum no load speed screw to bring the speed to the lower limit specified by the manufacturer. Adjustments to diesel injection pumps should be carried out by a  mechanic who is competent and familiar with diesel injection equipment. Sometimes it is possible to wind the maximum no load speed screw in by 3 or 4 turns without any adverse affect on the performance of the engine. (b) After 1,500 miles (2,400Km) recheck the smoke emissions and no load speed, making adjustments to the no load speed as outlined in (a) above.
2-2-1	Ignition System  - Mechanical Advance Curve Test Procedure.
	(a) If c/b points are fitted, check and set the c/b points to the manufacturer's specified gap or dwell angle. (b) Connect a portable tachometer. (c) Connect a stroboscopic timing light to number 1 H.T. lead. (d) Remove vacuum advance pipe from the vacuum advance canister and blank off open end to avoid air bleed effect. (e) Start the engine. (f) Set initial ignition dynamic advance to manufacturer's specification (g) Starting with the initial idle speed record the engine rev/min and  ignition timing, then repeat at 1000 rev/min and continue in 500 rev/min steps intervals from 1000 rev/min up to 5000 rev/min. (h) Stop the engine and reconnect the vacuum pipe.  (i) Tabulate the results and compare with the manufacturer's specifications, not forgetting that the initial dynamic advance may need to be subtracted. If the manufacturer specifies in distributor rev/min and distributor advance do not forget to divide the engine rev/min and the corresponding advance by 2 before comparing with the specification. (j) If the advance is outside the manufacturer's specification limits, either overhaul the mechanical advance mechanism or replace the distributor. Remember to recheck the mechanical advance curve if the distributor is overhauled or replaced.
2-2-2	Ignition System - Vacuum  Advance Curve Test Procedure. (Using a Mityvac vacuum hand pump)
	(a) If c/b points are fitted, check and set the c/b points to the manufacturer's specified gap or dwell angle. (b) Connect a portable tachometer. (c) Connect a stroboscopic timing light to number 1 H.T. lead. (d) Remove vacuum advance pipe from the vacuum advance canister and blank off the end to avoid air bleed effect. (e) Connect the Mityvac hand vacuum pump to the vacuum advance canister. (f) Start the engine. (g) Set initial ignition dynamic advance to manufacturer's specification. (h) Set the throttle screw to give approximately 1500 rev/min and record the ignition timing advance. (i) From zero vacuum to 15.0" (380mm) hg, in 0.5" (12.5mm) hg stages, apply vacuum to the vacuum advance canister, adjusting the idle speed back to 1500 rev/min as necessary.  Recording the vacuum and corresponding ignition timing advance. (j) Stop the engine and reconnect the vacuum pipe. (k) Tabulate the results and compare with the manufacturer's specifications, not forgetting to subtract the mechanical advance at 1500 rev/min from the results. If the manufacturer specifies in distributor advance, do not forget to divide the engine timing advance by 2 before comparing with the specification. (l) If the vacuum advance is outside the manufacturer's specification limits, replace the vacuum advance canister. Remember to recheck the vacuum advance curve if the vacuum advance canister is replaced.
2-2-3	Ignition System  - Vacuum Advance Curve Test Procedure. (Without using a Mityvac Hand Vacuum Pump)
	(a) If c/b points are fitted, check and set the c/b points to the manufacturer's specified gap or dwell angle. (b) Connect a portable tachometer. (c) Connect a stroboscopic timing light to number 1 H.T. lead. (d) Using a "T" piece, plumb a vacuum gauge into the vacuum advance pipe. (e) Start the engine. (f) Set initial ignition dynamic advance to manufacturer's specification. (g) Starting with the initial idle speed, record the engine rev/min, vacuum gauge reading and ignition timing advance. (h) Repeat at 1000 rev/min and continue in 500 rev/min steps intervals from 1000 rev/min up to 5000 rev/min. (i) Tabulate the results after subtracting the corresponding mechanical advance for each interval and recording the respective vacuum reading against the ignition timing advance. (j) Compare with the manufacturer's specifications, not forgetting that if the manufacturer specifies in distributor advance, you must divide the engine ignition timing advance by 2 before comparing with the Manufacturer's specification. (k) If the vacuum advance is outside the manufacturer's specification limits, replace the vacuum advance canister. Remember to recheck the vacuum advance curve if the canister is replaced.
2-2-4	Spark Plug grade and gap.
	(a) Remove spark plugs from engine. (b) Check that they are the correct grade for the engine, if not replace with correct grade after setting spark plug gaps to 0.30" (0.75mm), unless the manufacturer specifies a greater gap. (c) If of the correct grade, examine for any damage to the porcelain insulation and ensure that the electrodes are sound. If in doubt renew them as a complete set, after setting the spark plug gap to 0.030" (0.75mm), unless the manufacturer specifies a greater gap.
2-3-1	Air Cleaner Test Diagnosis.
	(a) Examine the air cleaner element. Renew if dirty or damaged. (b) On oil bath type air cleaners ensure the gauze is clean and that there is no sludge build up in the oil reservoir. Replenish the oil with fresh oil of the recommended grade. (c) Ensure all breather pipes to and from the air cleaner are sound and not blocked with sludge. Renew as necessary. (d) Check that the air cleaner flap is set to the correct setting for the time of year. (e) Check the air cleaner spout for any debris such as dead leaves, which should be removed. (f) Ensure that the hot stove tube is sound and correctly installed. (g) Using a Mityvac hand vacuum pump check that the vacuum motor is functioning and that the flap travels fully from open to closed. (h) Ensure that all vacuum pipes are sound and fit securely. (i) Ensure that the thermo-switch is functioning by observing the flap operation from cold start to operating temperature. (j) Ensure that the air cleaner seals correctly both on the lid and on the carburettor. (k) On fuel injection and diesel engines ensure that the trunking between the air cleaner and the inlet manifold is not split, renewing where necessary.
2-4-1	Carburettor Choke/Cold Start Device Test Diagnosis
	(a) Check manual choke/ cold start device operating correctly. (b) Check automatic choke/cold start device operating correctly. (c) Ensure Choke flap not sticking. (d) Check and adjust fast idle to manufacturer's specification. (e) Check and adjust choke flap "pull down" to manufacturer's specification. (f) Check and adjust choke flap modulation to manufacturer's specification. (g) Check and adjust bi-metal spring operation. (h) Check and adjust bi-metal to correct index mark. (i) Check and adjust cold start device settings to manufacturer's specifications.
2-4-2	Carburettor Operation Test Diagnosis
	(a) Ensure the carburettor is the correct one for the engine. If necessary replace or re-calibrate. (b) Ensure float chamber is not contaminated with sludge. Clean as necessary. (c) Ensure no excessive wear on throttle linkage or throttle Shaft. Overhaul or renew as necessary. (d) On  CD, SU and VV  carburettors ensure needle and jet are correct size and not worn. Also ensure pistons do not stick or damaged. Check that diaphragms are not contaminated, damaged or distorted. Renew or replace as necessary. (e) Check and adjust float level to manufacturer's specification. (f) Ensure float needle/valve assembly not sticking or damaged. Clean or renew as necessary. (g) On fixed jet carburettors ensure, correct jets are fitted and that they are not damaged. Renew or re-calibrate as necessary. (h) Ensure throttle butterfly plate(s) not sticking. Clean and reset as necessary. On multi-choke/multi-carburettor applications, ensure that the throttle plates are synchronised as per the manufacturer's specification. (i) On multi-choke/multi-carburettor applications ensure that the mixture screws/metering needles are balanced.
2-4-3	Fuel Injection System Cold Start Device Test Diagnosis.
	(a) Ensure that all multiplugs, hoses and pipes are connected and are not damaged. Replace or renew as necessary. (b) Ensure all electrical components are within manufacturer's specification by using a multimeter and the test procedures stipulated by the manufacturer. Replace or renew components as required. (c) Where fitted, check operation of the warm up regulator, auxiliary air valve, cold start injector and all associated sensors. Replace or renew as necessary.
2-4-4	Fuel Injection System Test Diagnosis.
	(a) Ensure that the throttle body is not contaminated. Clean as necessary with WD 40 or equivalent carburettor cleaner. (b) Ensure that the throttle butterfly plate is set to the correct air gap specified by the manufacturer. (c) Ensure that the plenum chamber air valve plate moves freely and does not stick. Clean and adjust as necessary. In some cases it may be necessary to renew the metering control unit assembly. (d) Ensure that the mass air flow valve is free and not sticking. Clean as necessary using an appropriate recommended cleaner. If damaged or unable to be rectified by cleaning, it may be necessary to replace the mass air flow meter assembly. (e) Ensure all multiplugs, hoses and pipes are connected and are not damaged. Replace or renew as necessary. (f) Ensure all electrical components are within manufacturer's specified tolerances using a multimeter to the recommended procedures specified by the manufacturer. (g) Check the operation and spray pattern of the injectors. Replace or renew as necessary.
2-4-5	Diesel Excess Fuel/Cold Start Device Test Diagnosis.
	(a) Ensure that cold start/excess fuel device is not sticking. Free off if necessary. If still causing concern seek the assistance of your local diesel equipment specialist. (b) Ensure that all glow plugs are connected. Rectify as necessary. (c) Ensure that there is a live feed to glow plugs. Replace fuse/switch/wiring as necessary.
2-4-6	Diesel Fuel Injection Equipment Test Diagnosis.
	(a) Where there is evidence of diesel oil it is possible that there is a fuel leak. Examine both supply and return fuel lines. Ensure that there are no leaking connections or cracked pipes etc. Repair, replace or renew as necessary. (b) Check the condition of the fuel filters, and where fitted, water traps. Replace any filters that may be dirty and drain down and clean water traps. (c) Ensure the spill timing is to manufacturer's specification. Adjust if necessary. (d) Carry out a smoke test. If the result is high and there is a constant plume of black smoke when the accelerator pedal is held steady at about 2000 rev/min, it is a general indication that the pump is over fuelling, or that the governor is malfunctioning. Carry out checks as detailed in (c) and (e). If on the other hand there is an intermittent puff of black smoke, then the problem is more likely to be injector related, in which case carry out checks as detailed in (g) and (h) below. (e) Check that the maximum no load speed is set as detailed in 2-1-4. If necessary reset (f) If after carrying out (c) and (e) above, there is still a smoke problem, seek the assistance of a diesel injection equipment specialist as the injection pump may need to be re-calibrated or replaced. The specialist will ensure that the pump calibration and governor advance curve is to specification. (g) Carry out a morse test by slackening the injector pipes one at a time. This will assist to locate which injector or injectors are a cause for concern. (h) Alternatively, remove all the injectors and examine the nozzles. Any that have an odd pattern or look oily could be suffering from dribble or be dirty or the break pressure could be out of specification. In any event, if the injectors are suspect, it is advisable to have all of them checked out by a diesel injection equipment specialist. He will either, clean and overhaul them, or supply you with a reconditioned set of the correct injectors.
2-5-1	Positive Crankcase Ventilation (PCV) System Test Diagnosis
	(a) Ensure all pipes are clear of sludge and not contaminated. Clean or replace as necessary. (b) Check the operation of the PCV valve. Replace if faulty or looks heavily contaminated. In the case of PCV valves with diaphragms, ensure that the diaphragm and spring are serviceable, i.e not split contaminated or weak. Replace or renew as necessary.
2-5-2	Engine General Condition Test Diagnosis
	(a) Look over the engine an assess the general condition. A heavily oil solied engine can indicate that the engine has a major oil burning problem. (b) Establish from the customer how many miles he covers before he has to top up the engine oil, Try and establish how much oil he has used between services in order to "guestimate" the oil consumption. (c) If the customer cannot give any indication of oil used, then have the engine cleaned, top up the oil to the maximum level mark on the dipstick. Record the mileage and/or zero the trip meter. (d) Ask the customer to return when the oil level is down to the minimum mark on the dipstick. (e) At that time record accurately the amount of oil needed to bring the level up to the maximum mark and record the mileage. (f) By subtracting the earlier mileage, the distance covered can be calculated. (g) Divide this by the quantity of oil used to top up the level to maximum and you will establish the number of miles the engine is doing to the litre (pint). If this is less than 1000 miles to the litre (600 miles to the pint) It is a good indication that in the absence of any major oil leaks, there is excessive engine wear. (h) Carry out an emission test both visual and with a 2/4 gas analyser. (i) A blue hue and high HC indicates that the valve stem oil seals could be worn. (j) To establish whether other causes are responsible, it will be necessary to carryout a cylinder compression pressure test and/or a cylinder leakage test. (k) If these test do not indicate bore wear or cylinder head/valve problems then the valve stem oil seals or worn guides are probably the problem. In such cases it would be advisable to check for valve guide wear when changing the valve stem oil seals. Excessive wear will necessitate the cylinder head being removed. Either to be overhauled or replaced with a new or reconditioned one.
2-6-1	Cylinder Bore and Piston Condition Test Diagnosis
	(a) Carry out a dry cylinder leakage test as detailed in (b) to (i) below. (b) Start the engine and warm up to normal working temperature. (c) Stop engine  (d) Isolate the ignition so that the engine will not start whilst it is cranked during the test. On diesels pull out stop or isolate stop solenoid so engine will not start (e) Remove one spark plug (diesel injector) and insert a compression gauge in the plug hole. (f) Ask somebody to assist by cranking the engine, (whilst holding the accelerator pedal down on petrol engines), for about 10 seconds, or until you ask them to stop when the highest pressure is registered on the compression gauge. (g) Record the pressure achieved and tabulate against the cylinder tested. (h) Replace the spark plug (diesel injector) and remove the next cylinder spark plug (diesel injector). (i) Repeat steps (b) to (h) until all cylinders have been tested. (j) Compare the results with the limits specified by the manufacturer. There should not be any greater variance than 10% between the highest or lowest readings. (k) If the pressures are below those expected. Repeat the cylinder compression test detailed (b) to (j) above, but this time pour some oil into each cylinder before inserting the compression gauge. (l) If the pressures are increased and reach those expected and in line within 10% between the highest and lowest readings, then indications are that there is excessive blowby due to bore wear and/or worn piston rings. (m) If this is the case, then advise the customer that the engine should either be reconditioned, or replaced with a new or exchange unit.
2-6-2	Cylinder Head and Gasket Test Diagnosis
	(a) If the cylinder compression test does not indicate excessive cylinder bore and/or piston ring wear, carry out a cylinder leakage test as detailed in (b) to ( ) below after allowing the engine to cool sufficiently so that the radiator cap can be removed safely. (b) Remove radiator cap when safe to do so. (c) Remove the dipstick. (d) Remove all spark plugs (diesel injectors). (e) Turn engine slowly until one cylinder is at TDC with all valves closed, i.e the compression stroke. (f) Screw the cylinder leakage test adaptor into the plug hole/injector hole. (g) Place the vehicle in gear (select park on an automatic) (h) Ensure the hand brake is fully on. (i) Connect the cylinder leakage test adaptor to the cylinder leakage meter tube/pipe and connect same to the meter itself. (j) Connect the cylinder leakage test meter to the air supply. (k) Apply air pressure slowly until reading stabilises and record the percentage of air leakage. (l) Listen for any air escaping. Ascertain and note its location. (m) Tabulate the results of the test against the appropriate cylinder. (n) Repeat steps (d) to (l) above until all cylinders are tested. (o) Analyse the results. (p) Cylinder leakage over 10% indicates a problem. (q) Air escaping through an adjacent cylinder plug/injector hole indicates a probable cylinder head gasket problem. (r) Air escaping from the exhaust pipe indicates an exhaust valve sealing problem. (s) Air escaping into the inlet manifold and out through the air cleaner spout indicates an inlet valve sealing problem. (t) Bubbles coming from the radiator indicate a head gasket problem. (u) Air coming from the dipstick tube indicates bore/piston ring wear. (v) Advise the customer of the results and agree a remedial course of action.
2-7-1	Auto vacuum Kickdown Diaphragm Test Diagnosis
	(a) Remove pipe from inlet manifold adaptor. (b) Inspect for traces of Auto transmission fluid and sniff for any traces of the smell of auto transmission fluid. If Indications are there of a presence of auto transmission fluid, then renew unit. If not detectable then as a final check proceed as detailed in (c) to (e) below. (c) Connect pipe to a mtyvac hand vacuum pump (d) Apply a vacuum until highest reading attained (e) If vacuum decays very quickly or cannot be sustained, the indications are that the diaphragm is split or perforated. In which case it should be renewed.
2-8-1	Brake Binding Test Diagnosis
	(a) Take the vehicle on a test drive avoiding any medium to heavy braking. (b)  After the test drive feel all of the wheels. Any that are hot or warmer than the others are possibly binding. There will also be a strong smell of friction material getting hot. (c) Release handbrake and ensure vehicle in neutral on a level surface. With the front wheels in the straight ahead position push vehicle along. If it rolls relatively freely then the brakes are not binding. (d) If the vehicle requires a lot of effort to push or when you stop pushing it stops immediately, the brakes are binding. (e) Jack up the vehicle and investigate further.  (f) Either adjust brakes where applicable or renew any seized calipers/wheel cylinders.
2-8-2	Clutch Slipping Test Diagnosis
	(a) If the engine speed seems high for the road speed in the gear selected on a manual gearbox, then it may be the clutch slipping. (b) Drive to a place where there is a steep hill and the traffic is light. (c) In a safe location, i.e. away from blind bends, stop the vehicle and apply the hand brake. (d) Select gear and slowly engage the clutch keeping the engine speed at about 2500 rev/min. (e) If the engine stalls when the clutch is fully engaged then there is no problem  (f) If the engine is still running when the clutch is almost fully engaged or fully engaged then the clutch is slipping and needs to be investigated.