2.0 EFI Lucas engine settings

[Sprint]

Hi all! Got myself a 1985 Montego EFI, only done 28,000 very clean but had some historical running problems by the look of it.
One or many people have had a go at it previously as I can see lots of new parts, marks around the throttle screws etc etc.

I’ve had a good search and read many posts which have helped me a long a bit further but I’m stuck in a loop as there are some fundamental settings I cannot find specs for…

Im hoping someone has the following info so I can reset everything and work from a baseline.

1: Stock butterfly to throttle body clearance?
Haynes manual says 0.038mm / 0.0015 but is this true, seems rather large.

2: CO screw turns out from fully in/closed?
This I understand is a sensitive adjustment but mine screwed very far out it seems and has no effect.

3: Idle stepper motor plunger distance?
My stepper motor moves fine but I noticed the plunger can screw in rand out, is there a dimension for this?

4: Standard fuel pressure with and without vacuum?

5: Standard hot idle speed.

I have done a lot already but without knowing a start point for 1 & 2 I’m stuck in a perpetual loop!

Help please!!

[Jeff Turbo]

Firstly , what are the running problems before anything else gets adjusted ? You can not just adjust the mixture screw without the ECU trying to compensate , do you have access to an emissions tester ?

[Sprint]

Basically the car hasn’t really been used for many years, just started up and moved around.
Apparently it’s always run ‘lumpy’.

Yes I have an exhaust analyser.
I realise this management system works in a very small window hence wanting to get all the mechanical parts back in spec.

[Jeff Turbo]

Running lumpy could be a host of issues as it's been messed about with. From plugs being at the wrong gap, air flow meter, ambiant air sensor, air getting in the system, leaks in the pipe from the ignition ecu to the inlet, incorrect emissions, faulty temp sensor, blockage in the return to the tank pipe, old fuel etc etc
Where in the UK are you as a fast check plug in would be ideal for you to start with?

[Jeff Turbo]

I can lend you this,

[Jeff Turbo]

And this

[Sprint]

Hi Jeff, thankyou kindly for the offer of the specialist kit, I imagine they are very rare these days!
Im near Ashford in Kent.

I have manually tested all components with multi meter etc and everything seems to check out.

I have also checked all vacuum hoses / crankcase hoses, intake / throttle body gaskets and replaced where needed, Im confident everything is air tight.

Injectors have been cleaned and I have personally checked CC per min and spray pattern.

The only faulty parts I’ve actually encountered so far are the fuel pump and the regulator (which is not reducing pressure und vacuum/idle).
I should have this part tomorrow.

It runs well but rich because of above I’m hoping, but I need to dial in the correct air and throttle settings.

So at this point I want to get the aforementioned items mechanically set to factory positions so I have a base line.
Is that info known?

I imagine there’s lots of lost knowledge over the years.

[Jeff Turbo]

Have a read https://maestro.org.uk/forums/forum/...diagnostic-kit

[Jeff Turbo]

And this https://maestro.org.uk/forums/forum/...l-pressure-reg

[Sprint]

Hi, yes read the first thread previously, re the second thread and fuel pressure, is mine classified as an early model?

I get the TPS mV setting etc, however is the 0.015” butterfly clearance correct? Seems overly large, and idle is very high with stepper motor closed.

[Sprint]

PS is there a known start point for the CO screw, eg 2 turns out from closed or something?

[Jeff Turbo]

Hi, yes read the first thread previously, re the second thread and fuel pressure, is mine classified as an early model?

I get the TPS mV setting etc, however is the 0.015” butterfly clearance correct? Seems overly large, and idle is very high with stepper motor closed.

Yes yours is an early model, possibly with a vacuum heater which can also affect tickover. I can find anything about the butterfly clearance but I've never seen a complete worn out one . As it's only done little miles it shouldn't be very worn out so leave as is. If idle is high you possibly need to reset the cold idle as per Gary's, (GForce), instructions if you can't adjust via the stop screw. CO screw would be set at the time of the emissions of the year which changes due to MOT years which is 1.0% to 1.5% hot, and 2.0 to 2 5 hot depending on the regulator as there are two types.

[Sprint]

The problem is it’s been meddled with already, the throttle isn’t in the standard position for sure.

If anyone has a well running or unmolested throttle that could measure the clearance it would be GREATLY appreciated

[Sprint]

[Jeff Turbo]

The throttle standard position is governed by the tick over screw that adjusts it. If the tick over is too high you should loosen the screw so it drops. If on first start up the tick over is very high you should do what Gary has suggested with the auto choke and reset it for cold start. Then you reset the mixture screw with your emissions tester. If the potentometer has been moved there's also a procedure to check that with a multimeter