Maestro Turbo Ignition problems

[Sussex Pete]

Rather than continuing with the Panic Stations! thread, I thought I had better start one with a more specific subject. The basic situation is that I have no spark at the plugs at all. There is a new coil (confirmed OK), new HT leads, new plugs and the ECU has been sent away for bench testing and returned as working OK. Using Jeff's loaned ignition analyser boxes, they indicate that at least the wiring and sensors are behaving as expected. Pictures below taken during the last test run and show the static, dynamic and fuel ECU test results.

A time-served auto electrician has also been through the system and arrived at the same conclusion I have - basically no **** idea! His suggestion is to find another turbo owner with a running car and carry out and ECU swap to prove one way or the other if its a good 'un. I've made contact with a member in Chichester and currently waiting a response.

[mrjones]

Rather than continuing with the Panic Stations! thread, I thought I had better start one with a more specific subject. The basic situation is that I have no spark at the plugs at all. There is a new coil (confirmed OK), new HT leads, new plugs and the ECU has been sent away for bench testing and returned as working OK. Using Jeff's loaned ignition analyser boxes, they indicate that at least the wiring and sensors are behaving as expected. Pictures below taken during the last test run and show the static, dynamic and fuel ECU test results.

A time-served auto electrician has also been through the system and arrived at the same conclusion I have - basically no **** idea! His suggestion is to find another turbo owner with a running car and carry out and ECU swap to prove one way or the other if its a good 'un. I've made contact with a member in Chichester and currently waiting a response.

[mrjones]

If everything is working as you say above then the problem must be with either the rotar arm or dis say cap.

[mrjones]

Sorry that's supposed to say dizzy cap

[Jeff Turbo]

As Stuart says, have you tested the rotor arm Pete? Is power getting to the distributor cap as the fast checks etc clearly show all sensors and coil are ok. Can only be ecu, rotor arm, bad earth or distributor cap

[Sussex Pete]

All plug tests so far have been direct from the coil to take the rotor arm and dizzy cap out of the equation.

[G Force]

Hi all
Looking at the response of the fast checks I notice on the static test of the ignition test the L/H crankshaft LED is illuminated. I would check with Jeff if this is the correct result for that particular fast check? The Austin Rover programmed ignition fast check that I am familiar with is very similar to the Lucas one you are using but not exactly the same. The correct response for a static test of the AR fast check would be Ignition & Coil LED’s illuminated and the L/H Crankshaft, Knock & (Coolant which is not present on your version) all extinguished. An illuminated crankshaft L/H LED on a static test would indicate a possible short to earth in the crank sensor wiring or faulty crank sensor. This may not be the problem with your ignition system especially given that the dynamic test results are OK but it is worth just checking the integrity of the crank sensor and wiring.

Not related to the ignition problem but I thought worth a mention, the correct response for the fuel management fast check is Ignition, Throttle, & Coil LED’s illuminated and all other LED’s extinguished. The throttle LED not on is most likely due to the throttle pedal switch bracket that will need bending slightly so the pedal is in direct contact with the switch its self in order to close the switch. The LED should only go out when the throttle pedal is pressed. The stepper motor Hi LED illuminated indicates a high resistance in the stepper motor or wiring. This more often than not turns out to be a red herring when checked out and is due to the over sensitivity of the fast check, but if you have any issues with the choke once you get the engine running then it will be worth checking.

Cheers. Gary

[Sussex Pete]

Thanks Gary, I appreciate the input as anything seen may just point to an overlooked issue! As far as the Lucas Analyzer is concerned, the LED's under each test mode are the ones that should be visible. So the crank sensor LED on the left is the static test and on the right is the dynamic test. Jeff sent me the book to go with the analyzer so I could follow the tests and results correctly!

On the fuel management ones, that is useful to know about the switch bracket. Its been added to the snagging list to deal with as soon as I get a spark at the plugs! Also, I wasn't concerned with the stepper motor LED as I hadn't heard the stepper motor operating when I switched the ignition on for that test, it had already been operating a number of times during all the previous tests AND its a brand new stepper motor, fitted by Southern Carburettors when they overhauled the carb.

[Jeff Turbo]

Hold the end of coil lead about 1/4in from an earth and crack it over. If no spark connect a voltmeter across ignition ecu pin 9 and 12, does it register voltage about 10 seconds after switching ignition on.

[Sussex Pete]

Hold the end of coil lead about 1/4in from an earth and crack it over. If no spark connect a voltmeter across ignition ecu pin 9 and 12, does it register voltage about 10 seconds after switching ignition on.

Got to the stage of confirming I can get a spark (although a very weak one!) from the coil through the car wiring but splashing the earth direct to the battery. Yes, got voltage between pins 9 & 12. At the mo' everything appears to be pointing to a duff ignition ECU. Currently looking for someone local who has a running turbo, so I can do a quick ECU swap to prove it one way or the other.

[E_T_V]

Any ECU even a non turbo one will work to prove the point (just don't run the car under load).

[Sussex Pete]

Any ECU even a non turbo one will work to prove the point (just don't run the car under load).

Already been down this road, Dan. As I noted in post #39 of the Panic Stations! thread, I was told that using another ECU won't work even as a test because they take different signals. Hence the lack of rationalisation across the Maestro range. Also read the same sort of information on a thread from a few years ago on this forum.

[Sussex Pete]

Sort of thinking out loud, I was just wondering about the plugs and leads. Reason being that there was no spark with new plugs and one of the new HT leads, but there was with the old plug and HT lead. The old plug is an NGK BP6ES, but the recommended is GSP4452, which equates to Champion RN7YC or NGK BPR7ES.

I understand that resistor plugs are recommended in any car that has electronic components like an ECU as it reduces the electromagnetic interference that the spark plug creates. So, that would mean that resistor plugs are a requirement for our cars. My thoughts were, should I be looking to but copper HT leads rather than the carbon string type that I have got and is there any benefit in changing the plug heat range. Finally should I ditch the Champion plugs and get some NGK's, in case my issue has been the new plugs all along?

[E_T_V]

Test the king lead half an inch from the engine block. It should have a nice strong regular spark. If yes and the plugs don't well err spark then the rotor arm is the most likely suspect (new ones have been known to be faulty), or indeed check it doesn't spin in the cam, (making the gap in the distributor too big to jump). HT leads are resistor leads and plugs are resistor plugs as standard.

[Sussex Pete]

Test the king lead half an inch from the engine block. It should have a nice strong regular spark. If yes and the plugs don't well err spark then the rotor arm is the most likely suspect (new ones have been known to be faulty), or indeed check it doesn't spin in the cam, (making the gap in the distributor too big to jump). HT leads are resistor leads and plugs are resistor plugs as standard.

Haven't been getting the spark from the king lead, Dan. This is why I have been flummoxed by what could be wrong, especially considering the test results in the photos in the 1st post here. Continuing my thoughts about where to look, I returned to Jeffs suggestion about the crank sensor. Now as the tests show that the crank sensor is apparently OK, I did wonder if the green light on the dynamic test is confirming that there is a pulse coming from the sensor at the correct times, or that there is just a current through the sensor.

Reason to go down this route, is that I fitted an early Rover 820 flywheel so that I could go to a bigger clutch. While I am sure that I checked the original and new flywheels side by side before fitting the new one, to ensure that the stator ring and starter teeth were the same on both, I'm now wondering if the Turbo crank sensor is the correct length to get the magentic field breakdown and create the pulse. If the analyser is confirming a pulse is present, then I back to suspecting the ECU, otherwise I'm wondering if it will be worth the effort to check the fitting of the crank sensor in relation to the flywheel stator ring.