QUESTION
I finally got to put a timing light onto the flywheel but something doesn't add up.
According to the manual to set the distributor pulley you need to run a line from the crank centre to the distributor pulley centre and the green dot should line up.
I couldn't get the distributor around enough to advance the timing.
I needed to shift the pulley over by two teeth to the left of the centre line.....
After finally getting the 9 degrees at idle, I rev the engine and it cuts out at 2500 rpm where the advance returns to TDC....
When the engine is back at idle it is a 9 degrees BTDC.
The timing actually retards when revved, which I have never experienced before...
The Esprit runs, I just can't get past 2500rpm and I can also hear the turbo spooling and the boost gauge registers boost at 2500rpm....I found this odd as the car never had any boost before when revving the engine....
All cylinders have 150psi compression.
I adjusted the cam pulleys so both green dots align inside the cam block valley.
I aligned the distributor pulley as per the instructions but the cam lobe in the distributor wouldn't line up to 9 degrees BTDC.
I had to advance the green dot two teeth from the imaginary centre line of the distributor pulley and crank pulley.
When I start the car cold it advances to 40degrees and then as it warms it drops back to 10degrees at idle.
When I rev it to 2500 rpm the timing light is showing TDC and the engine starts stalling until I back off the throttle where it goes back to 9 degrees BTDC.
My vacuum advance has two lines in it. I disconnected the top part of the diaphragm and sucked with a syringe and it gets full travel of advance.
So the distributor part seems OK. I wasn't sure if it was perhaps the thermal ignition valve as the car seems to be able to rev higher when cold for a minute or so.
After that when it warms up it is stuck under 2500rpm..
When I test the mechanical advance do you want me to just disconnect the vacuum lines or plug them off completely?
V.L - Prospect, NSW
ANSWER
As I cannot see your Esprit and check some basic settings then its necessary to go back to basics.
The first check is to make sure the valve timing is correct by checking the dots on the various pulleys.
The next check is to make sure the distributor position, rotor arm orientation and inductive pick-up are phased correctly.
http://www.lotusmarques.com/info/technical/30-lotus-esprit/1207-1988-1992-lotus-esprit-ignition-timing
At this point it is necessary to disconnect the vacuum connection to the distributor before starting the engine.
After starting the engine, it is essential to check that the mechanical advance works correctly.
You will need a timing light to do this at the flywheel.
The distributor on your Esprit should have a single vacuum hose connection to the advance control module.
Lotus Service Notes Section EME
Key to Vacuum Connection Diagram
1. Engine Speed Sensing Relay:
Fitted in ignition box. Energises throttle jack above 1600 rpm on rise (1400 rpm on fall) to reduce emissions on over-run. See E .6.
2. Crankcase Breather Valve:
Fitted at top rear of crankcase. Vents crankcase emissions to air-box, with bleed to carburettors. See E24E.3
3. Cold Enrichment Thermal Valve:
Fitted into rear of inlet manifold water rail. At water temps. below 35°C, valve shuts off crankcase breather bleed to enrich fuelling. See IIME.4.
4. Thermal Ignition Valve (T.I.V.):
Fitted to centre of inlet manifold water rail. Below 60°C directs vacuum pump signal to distributor for full advance to aid cold idle and driveability. See EME.2.
5. Throttle Jack Solenoid:
Fitted to front of forward carburettor. Controlled by speed sensing relay (item 1), choke switch and a.c. switch. Energised above 1600 rpm on rise (1400 rpm on fall) to reduce emissions on over-run and when choke/a.c. operated to raise/maintain idle speed. See-E4E.6.
6. Distributor Capsule:
Vacuum advance capsule receives signal via T.I.V from either throttle edge drilling or downstream of throttle plates dependent on water temperature. See ME.2.
7. Air Temperature Control (ATC) Sensor:
Regulates vacuum supply to ATC valve dependent on air-box. temperature. See E4E.7.
8. Thermal Switch:
Fitted in thermostat outlet water pipe. M.O.R. 70°C, B.O.F. 60°C. Switches airbox purge system. See II E.5.
9. Purge Pump:
Fitted to RH fuel tank board. Controlled by thermal switch (item 8). Operates at water temps. above 70°C with ignition off, to aid hot start. See E.5.
10. Air Temperature Control (ATC) Valve:
Switches air intake to warm air supply from exhaust downpipe shroud at low air-box temperatures, for improved cold running. See II E.7.
EME.2 - THERMAL IGNITION ADVANCE
The thermal ignition advance system is designed to aid driveability and idle speed when cold, and light load economy when warm.
The thermal ignition valve (TIV) is fitted into the centre of the inlet manifold water rail and senses engine coolant temperature.
Three ports are provided on the valve, D, 1 and 2.
At coolant temperatures below 60°C, ports D and 1 and connected, whereas at temperatures above 60°C, ports D and 2 are joined.
Thus at low engine temperature, the distributor capsule (port D) receives a pressure signal (via port '1') from the carburettor ports downstream of the throttle plates to provide over 30° of ignition advance at cold idle to raise idle speed and improve driveability.
At normal engine temperature, the distributor capsule receives a pressure signal (via port '2') from a throttle edge port on the front carburettor barrel to provide ignition advance at part throttle for improved light load economy.
Update - 3rd February 2016
After dismantling the distributor, this problem was finally traced to a broken spring in the mechanical advance mechanism.
Copyright © 2016 Lotus Marques
I finally got to put a timing light onto the flywheel but something doesn't add up.
According to the manual to set the distributor pulley you need to run a line from the crank centre to the distributor pulley centre and the green dot should line up.
I couldn't get the distributor around enough to advance the timing.
I needed to shift the pulley over by two teeth to the left of the centre line.....
After finally getting the 9 degrees at idle, I rev the engine and it cuts out at 2500 rpm where the advance returns to TDC....
When the engine is back at idle it is a 9 degrees BTDC.
The timing actually retards when revved, which I have never experienced before...
The Esprit runs, I just can't get past 2500rpm and I can also hear the turbo spooling and the boost gauge registers boost at 2500rpm....I found this odd as the car never had any boost before when revving the engine....
All cylinders have 150psi compression.
I adjusted the cam pulleys so both green dots align inside the cam block valley.
I aligned the distributor pulley as per the instructions but the cam lobe in the distributor wouldn't line up to 9 degrees BTDC.
I had to advance the green dot two teeth from the imaginary centre line of the distributor pulley and crank pulley.
When I start the car cold it advances to 40degrees and then as it warms it drops back to 10degrees at idle.
When I rev it to 2500 rpm the timing light is showing TDC and the engine starts stalling until I back off the throttle where it goes back to 9 degrees BTDC.
My vacuum advance has two lines in it. I disconnected the top part of the diaphragm and sucked with a syringe and it gets full travel of advance.
So the distributor part seems OK. I wasn't sure if it was perhaps the thermal ignition valve as the car seems to be able to rev higher when cold for a minute or so.
After that when it warms up it is stuck under 2500rpm..
When I test the mechanical advance do you want me to just disconnect the vacuum lines or plug them off completely?
V.L - Prospect, NSW
ANSWER
As I cannot see your Esprit and check some basic settings then its necessary to go back to basics.
The first check is to make sure the valve timing is correct by checking the dots on the various pulleys.
The next check is to make sure the distributor position, rotor arm orientation and inductive pick-up are phased correctly.
http://www.lotusmarques.com/info/technical/30-lotus-esprit/1207-1988-1992-lotus-esprit-ignition-timing
At this point it is necessary to disconnect the vacuum connection to the distributor before starting the engine.
After starting the engine, it is essential to check that the mechanical advance works correctly.
You will need a timing light to do this at the flywheel.
The distributor on your Esprit should have a single vacuum hose connection to the advance control module.
Lotus Service Notes Section EME
Key to Vacuum Connection Diagram
1. Engine Speed Sensing Relay:
Fitted in ignition box. Energises throttle jack above 1600 rpm on rise (1400 rpm on fall) to reduce emissions on over-run. See E .6.
2. Crankcase Breather Valve:
Fitted at top rear of crankcase. Vents crankcase emissions to air-box, with bleed to carburettors. See E24E.3
3. Cold Enrichment Thermal Valve:
Fitted into rear of inlet manifold water rail. At water temps. below 35°C, valve shuts off crankcase breather bleed to enrich fuelling. See IIME.4.
4. Thermal Ignition Valve (T.I.V.):
Fitted to centre of inlet manifold water rail. Below 60°C directs vacuum pump signal to distributor for full advance to aid cold idle and driveability. See EME.2.
5. Throttle Jack Solenoid:
Fitted to front of forward carburettor. Controlled by speed sensing relay (item 1), choke switch and a.c. switch. Energised above 1600 rpm on rise (1400 rpm on fall) to reduce emissions on over-run and when choke/a.c. operated to raise/maintain idle speed. See-E4E.6.
6. Distributor Capsule:
Vacuum advance capsule receives signal via T.I.V from either throttle edge drilling or downstream of throttle plates dependent on water temperature. See ME.2.
7. Air Temperature Control (ATC) Sensor:
Regulates vacuum supply to ATC valve dependent on air-box. temperature. See E4E.7.
8. Thermal Switch:
Fitted in thermostat outlet water pipe. M.O.R. 70°C, B.O.F. 60°C. Switches airbox purge system. See II E.5.
9. Purge Pump:
Fitted to RH fuel tank board. Controlled by thermal switch (item 8). Operates at water temps. above 70°C with ignition off, to aid hot start. See E.5.
10. Air Temperature Control (ATC) Valve:
Switches air intake to warm air supply from exhaust downpipe shroud at low air-box temperatures, for improved cold running. See II E.7.
EME.2 - THERMAL IGNITION ADVANCE
The thermal ignition advance system is designed to aid driveability and idle speed when cold, and light load economy when warm.
The thermal ignition valve (TIV) is fitted into the centre of the inlet manifold water rail and senses engine coolant temperature.
Three ports are provided on the valve, D, 1 and 2.
At coolant temperatures below 60°C, ports D and 1 and connected, whereas at temperatures above 60°C, ports D and 2 are joined.
Thus at low engine temperature, the distributor capsule (port D) receives a pressure signal (via port '1') from the carburettor ports downstream of the throttle plates to provide over 30° of ignition advance at cold idle to raise idle speed and improve driveability.
At normal engine temperature, the distributor capsule receives a pressure signal (via port '2') from a throttle edge port on the front carburettor barrel to provide ignition advance at part throttle for improved light load economy.
Update - 3rd February 2016
After dismantling the distributor, this problem was finally traced to a broken spring in the mechanical advance mechanism.
Copyright © 2016 Lotus Marques