montego tickover

[tony]

I am new to the club having only this week bought my 1988 mg
montego 2.0 efi.when I drove it home I noticed the revs where either too
high are too low is there anything I should look for.also when I
started the journey home I put unleaded in the tank but when I got home I
found a owners handbook which said use leaded.would that cause the revs to
change?thanks mike
i was asked this but i am not sure where his problem lies can anyone help:)

[G Force]

Hi there. Putting unleaded petrol in the tank would not cause problems with the idle speed, nor would I be too concerned about any consequences of putting unleaded petrol in, as the o2 engine has always had unleaded capability just that the early ones were tuned for leaded.

The problem is most likely due to the throttle body settings. First thing to do is to remove it and give it a thorough cleaning with carburetor cleaner. Then once re-fitted, reset the base idle and co setting then adjust the throttle potentiometer setting at idle.

Cheers Gary:)

[Landcrab1800]

Hi,

Although I generally agree with G Force I am not 100% certain that unleaded will not affect tick over. Un leaded burns at a higher temp than leaded, this could cause the temp to run higher, this means that the ECU will reduce the fuel but will try to compensate this by trying to keep the CO2 level at the pre programmed level.

Personally I'd go for the throttle swithch which is hidden behind the throttle, WELL hidden and a pig to change. OR get the motor tuned for unleaded (Home tuning companies cost about £50)


Cheers


Gordon

[MGTurbo]

Originally posted by Landcrab1800
Hi,

Although I generally agree with G Force I am not 100% certain that unleaded will not affect tick over. Un leaded burns at a higher temp than leaded, this could cause the temp to run higher, this means that the ECU will reduce the fuel but will try to compensate this by trying to keep the CO2 level at the pre programmed level.

Cheers


Gordon

C02 level cannot be measued as it doesnt have a lambda sensor, the igntion will be as per it's pre-set parameter's dependant on various sensor values, and at idle there is going to be virtually no difference between unleaded and the now defunct 4-start which has been out of general public sale for over 4 years now.

To me it sounds like the stepper motor needs resetting. You should also always allow the EFi fuel system to correctly pressurize on a start by allowing a few seconds once the ignition has been turned on.

Gareth

[Blair G]

I am new to the club having only this week bought my 1988 mg

I had the same problem and went to MG Rover Works about it, they told me it was the automatic choke sticking on (temp sensor fault).When I asked for a price I thought they were having a laugh!!!
There is a sensor pluged into the intake at the back, I pulled this out and it solved the problem although it has to be pluged back in on cold mornings but can be pulled back out soon as it starts. I have not had any other problems running it this way.