L.1 - GENERAL DESCRIPTION - Section Menu The fuel system has a fuel tank located in the engine compartment on the left hand side.
L.2 - FUEL TANK - Section Menu
To Remove: To Replace:
L.3 - FUEL TANK SENDER UNIT - Section Menu
To Remove: To Replace: L.4 - FUEL GAUGE - Section Menu
To Remove: To Replace:
L.5 - FUEL PUMP - Section Menu
To Remove: To Replace: FUEL PUMP FILTER
To Remove: To Replace: FUEL PUMP OVERHAUL To Replace:
To assemble the operating arm, place the diaphragm assembly in position in the lower body with the seating seal in its recess. Squeeze the diaphragm and body together against the spring pressure and insert the forked end of the lever between the raise end of the diaphragm push rod. When assembling the two halves of the body together, loosely fit the screws and tighten them all a little at a time to ensure that the diaphragm which is clamped between them is sandwiched in a 'flat' condition. L.6- AIR FILTER - Section Menu
To replace air filter element (every 12,000 miles - 20,000 km): To remove the body. To replace the body.
Special Note.
L.7 - CARBURETTOR - SOLEX F35 DIDSA - 2 - Section Menu
General description. Lotus Europa models supplied for the U.K and European markets are fitted with a Solex carburettor of the above type. The carburettor details vary slightly according to the vehicles series and specification but the principle of operation and basic details remain the same for all carburettors without emission control. The Solex instrument is a twin choke and twin barrel unit, which overcomes certain disadvantages on single choke carburettors when engine outputs are increased beyond moderate ratings, particularly if it is required to provide a good part throttle performance. On the Europa application one barrel is tuned to give good economy at intermediate throttle openings and the other to give maximum performance when operating in conjunction with the first. The primary throttle is operated over its whole range by the movement of the accelerator pedal. The action of the secondary throttle is automatic and depends on the position of the primary throttle and the amount of vacuum in the primary throttle choke tube. The secondary throttle is prevented from opening by an overrider lever or ramp link Q. Fig. 5 until the primary throttle is at least two thirds open. Then, if the required vacuum is created in the venturis, the diaphragm in the vacuum control unit will lift and open the secondary throttle. These actions are shown in Fig.7. In order to provide extra fuel required for immediate response to sudden openings of the throttle an accelerator pump is provided as shown in service assemblies (Fig 10). (The rod linking it to the primary throttle lever may also be seen in the lower body assembly of this illustration). Maintenance and Slow-running Adjustment. - Section Menu The only maintenance required apart from servicing the air filter (see chapter L.6) [2] is to ensure that the Jets are not obstructed. On no account should any wire be used to clear a Jet.
Key to Fig.7
B - Primary throttle operating range, when engine speed is too low to provide the necessary suction in the primary throttle choke tube, to actuate the secondary throttle operating unit. C & D - Primary throttle (1) movement needed when sufficient suction exists in the primary choke tube to open the secondary throttle (2). (C) half way, (D) fully open. Slow-running Adjustment. This the only adjustment which should be required in normal use and is carried out as follows:
Adjust the slow-running volume control screw K so that the engine is running evenly with the screw rotated as far anti-clockwise as possible. Readjust the engine speed if necessary with the speed adjustment screw J. This is obtained by having the volume control screw K rotated anticlockwise as far as possible consistent with even running at the idling speed. Carburettor faults: - Section Menu
Bad slow-running: Difficult starting: Poor top speed performance: Removing and Refitting the Carburettor. - Section Menu To Remove:
Remove the rear luggage compartment, by undoing the two bolts set in the floor of the unit. Take care to note the quantity and position of the spacer washer situated between the cross member and the under-surface of the compartment. Remove the air filter and body (see section L.5). - Figure 8 -
- the vacuum pipe. - the choke wire. - the accelerator return spring. - the fuel pipe. - the accelerator cable at the 8 mm. hex clamp bolt. Undo the two worm-drive hose clips and pull the manifold heater pipes from their unions at the right hand base of the manifold. Remove the carburettor securing nuts and washers and lift off the instrument. Blank off the flange on the inlet manifold to prevent the entry of any foreign matter. To Refit:
Dismantling the Carburettor. - Section Menu - Figure 9 -
Access to the jets or float can be made of course by removing the upper body only. Before dismantling it is suggested that a gasket kit be obtained - separating the bodies of instruments that have seen long service without being disturbed previously, can result in torn gaskets. To remove the upper body. To remove the lower body from the main body. - Figure 10 -
To remove the vacuum control housing from the upper body: To dismantle the accelerator pump (situated in the main body). Assembling the carburettor. - Section Menu
Scrupulous cleanliness should be observed during the ensuing assembly procedures. All parts should be carefully cleaned and checked for damage and/or correct operation, as each unit is assembled. To assemble the accelerator pump: To assemble the lower body.
This action is determined automatically in the manufacture of the components and cannot be adjusted. The primary throttle should be free to travel to approximately 2/3rd open position before it is arrested by the stop on the rear of the slow-running arm. The remaining third open position can be effected by operating the secondary throttle roller lever until both plates are fully open. When assembling the lower body to the main body, ensure that the mating surfaces of the components are clean and that the gasket is in good condition. Refit the two cheese head screws and spring washers securing the lower body to the upper. Check that the secondary throttle is fully closed after this operation and only adjust the limit screw that bears against the under-surface of the float chamber if this condition does not exist. Tighten the lock nut if necessary and re-connect the accelerator pump link. To assemble the upper body (see special note at end of chapter). To refit the vacuum control housing. L.8 - CARBURETTOR - SOLEX 26DIDSA - 5F (EXHAUST EMISSION CONTROL) - Section Menu
General description of the system.
A Lotus Europa equipped with this system meets the applicable Federal Requirements. The main features of the Ranault D.C.S system are: The secondary throttle with the large cross section comes into use to meet engine requirements for heavier loads and higher speeds. To ensure that the secondary throttle of the curburetter comes into action at the correct time in order to satisfy the engine requirements, an actuating device which is sensitive to the engine demands is necessary. The progressive linkage selected for the Renault D.C.S. system makes use of a vacuum diaphragm unit. The vacuum which actuates the diaphragm is taken from the venturis of the two throttles. In the venturis, the vacuum increases when the throttle plates are opened, and further increases as the engine speed rises. As a result the action of the diaphragm is progressive and provides a smooth transition from the primary to secondary throttle. Periodic Maintenance
The maintenance intervals are the same as those recommended for the U.K and European vehicle (i.e., without the D.C.S. system) and are covered under Section O 'Lubrication and Maintenance'. Maintenance and slow-running adjustments - Section Menu Normal idle:
The screw acting on the opening of the throttle has been replaced by a screw acting directly on the flow of air through the external idle air circuit. The screw acting on the air flow is designated 'air screw', and the screw acting on the air/fuel mixture is designated 'petrol screw' (1 and 2 respectively of Fig. 13). Procedure:
Connect an electronic tachometer which is accurate to + 2.5%. Run the engine until it reaches normal operating temperature (i .e. until the radiator fan starts running). First step (Fig, 13):
To obtain this condition proceed as follows: Second Step:
Please note that particular care MUST BE TAKEN to ensure that this adjustment is performed with precision, because the level of carbon monoxide emissions depends for a large part UPON ITS ACCURACY. Positive crankcase ventilation system (Fig. 14) - Section Menu - Figure 14 -
Removing and Refitting the Carburettor. - Section Menu Removing.
Remove the rear luggage compartment by undoing the two bolts set in the floor of the unit; take care to note the quantity and position of the spacer washers situated between the cross member and the under surface of the compartment. Remove the air filter and body (see section L.6). Undo the worm drive pipe clip at the right hand side of the emission control valve housing and remove the pipe. Undo the pipe clip by means of key (part No 46E 6433) at the left hand side of the emission control valve housing and remove the pipe. Undo the 12 mm. hex. union at the float chamber and pull the fuel line clear of the carburettor. Pull the two remaining hoses away from the pipe entry above the choke plate complete with the 'Tee' piece. At the carburettor disconnect the following controls:
- the lead from the solenoid valve. - the vacuum pipe. - the accelerator return spring. - the accelerator cable at the 8 mm. hex. clamp bolt. Undo the two worm-drive hose clips and pull the manifold heater pipes from their unions and the right hand base of the manifold. Remove the carburettor securing nuts and washers and lift off the instrument. Blank off the flange on the inlet manifold to prevent the entry of any foreign matter. Refitting.
Dismantling the Carburettor. - Section Menu In order to ensure compliance with the Federal Regulations on air pollution control, the carburettor adjustments are factory set. This consequently influences the degree of dismantling permitted. The following operations are the only ones which may be performed and dismantling procedure is described only to achieve these ends. To remove the upper body. To assemble the upper body. To remove the vacuum diaphragm control unit. L.9 - CHOKE CONTROL - Section Menu
To Remove. To Replace. L.10 - THROTTLE - Section Menu
To Remove. To Replace. L.11 - EXHAUST EMISSION CARBURETTERS (Solex DIDSA 5 and DIDSA 9) - Section Menu Further to the information published in Section 'L.8', the following information on difficulties which could arise in Service, also applies.
Cold Start System
A lost motion linkage provides for an override control operated by a piston influenced by engine depression. The air bleed for the slow running by-pass system is positively closed, by operating the choke control fully through a plate valve contained in the choke/by-pass housing. For starting an engine from cold, the sequence of operations is therefore: Starting an Engine from Warm Starting an Engine Hot Slow Running (idle) System
For this reason the 'normal' idle stop screw is not fitted, control of the idle r.p.m, and mixture being given by the air bleed screw, (1 of Fig. 13) and the idle mixture screw (2 of Fig. 13). The screw (B of Fig. 13), which is locked with a paint (or similar) is Factory set and MUST NOT BE ADJUSTED. The purpose is to control the amount of throttle opening on fast idle (when the choke is in use) but misadjustment can open the throttle butterfly at all times, making it impossible to properly set the idle/r .p.m. mixture. To Set Idle R.P.M.
NOTE: All of the above information is contained in 'Technical Data'. Normal Running
Fault Diagnosis
Difficult Cold Starting attributable to carburation.
If not, check reason for limited movement and rectify. 'Hang Up' on Idle R.P.M.
Remove air cleaner and re-check for 'hang up'. If absent, fit new air cleaner. If screw 1 of Fig. 13 has been disturbed, weakening (by turning clockwise) may make an improvement. 'Running-On'
If engine continues to run, replace solenoid valve. Other than faults common to all carburetters - blocked jets etc., experience indicates that the majority of problems are caused by tampering with the pre-set screws. GOING BACK TO STANDARD will normally rectify obscure problems. L.12 - 1971 EVAPORATIVE LOSS CONTROL (EXHAUST EMISSION) - Section Menu To eliminate fuel vaporization into the atmosphere and thus comply with the 1971 U.S. Federal Motor Vehicle Safety Standards, an 'evaporative circuit' has been incorporated into the fuel system. - Figure 19 - - Figure 20 - - Figure 21 - The evaporative loss control system consists basically of the fuel tank vented into a catch tank, which will collect overflow fuel during conditions of extreme heat, or violent vehicle maneuvers. When the engine is off, vapor from both the fuel tank and the carburetter float bowl, are collected by an activated charcoal canister. When the engine is running, the float bowl is vented directly into the carburetter by the action of a throttle operated valve. 'Purge' air is drawn into the bottom of the charcoal canister and carries the vapor into the engine, either through the carburetter on wide throttle openings, or directly into the inlet manifold on small throttle openings. This distribution is achieved by the use of an AC valve in the manifold, which is closed at low manifold depression and opens at a higher manifold depression. The system is effectively maintained by renewing the charcoal canister at intervals of every 48,000 miles (60,000 km.). Editors Notes:
[2] Original stated 'see chapter L.5.' Changed to 'see chapter L.6' [JJ] [3] N.B.: An abbreviation for the Latin phrase 'nota bene', meaning 'note well.' It is used to emphasize an important point. [BB] Other Notes: [edit disabled for dial-up] |