start to jumping montego

[maltes]

Hi, good morning



Hope you could help me, I own a Rover montego 1.6 sl buildt up in 1989 (I have consulted various things here previously with successful results). Now I have a problem, when I change the gear and push the accelerator the car start to jumping in the following conditions: the temperature of the engine is warm and when the rpm are 1500. I changed the spark plugs 10000 km ago and the air filter as well. Last may the car passed the technical inspection without any problem.

I wonder if jumping is due to the fuel filter. Anyone knows where is it?.

This car is hardly used and always in city streets. I usually use it one per month but this years I almost didnīt use it.



Thanks so much for your help.



Best regards

[G Force]

Hello Maltes.

This could be something quite simple, so the first thing to check is that the plug leads are pushed fully onto the spark plugs.

If you can push the plug leads further onto the spark plugs, this can happen often after renewing the plugs. What happens is the trapped air inside the plug lead caps expands with heat and pushes the plug lead up the plug. To stop this happening again just squeeze the rubber plug lead cap hard between your thumb & fingers around the spark plug so that the air vents out.

If this is not the problem then you need to remove the plugs and check the gaps are set to exactly 0.040in of 1mm. Examine the colour of the plug nose, if it is very sooty this may be because of the type of driving that you have to do. or the wrong heat range. The recomended plug is NGK BCPR6ES if you fitted these or equivalant, it might be worth moving to NGK BCPR5ES for your infrequent use.

If the plug nose colour is white, then you need to check your vacuum pipes and breather hoses for air leaks, or if no leaks are present then have the CO checked & set to 2.5%.

Make sure the carburettor dash pot damper is topped up with 10W40 oil.

There is no standard fuel filter on your montego model.

Let us know if you find anything.

Regards, Gary

[maltes]

Good afternoon

Firstly I thank you so much for answering my question so quickly. The spark plugs and electrodes were a little bit white (i clean them up with a tissue and now they looks good) , but all of them were equal and nothing special was noticied.
There was a pipe which conects the carburator with one cylinder broken and the other pipe that conect the cilinder with electronic control unit. When i touched it the pipe broked completely down and the car still jumped. I replaced it with another pipe that is commonly used for fuel conduction, one of those which are wrapped around and the problems disappear.
I went for a walk with my car and when the engine turns at 1500-2000 rpm and push the accelerator the car seemed to be without power, and then increase the revolutions well and run ok.
I just remember that last year the car had problem for passing the annual vehicle thecnical inspection due to Co emmisions. I took my car to the garage and the mechanics changed something (i donīt know what). I wonder if this could be the cause of the problem of my car?

Thank for your help once again and regards.

[G Force]

I just remember that last year the car had problem for passing the annual vehicle thecnical inspection due to Co emmisions. I took my car to the garage and the mechanics changed something (i donīt know what). I wonder if this could be the cause of the problem of my car?

Thank for your help once again and regards.

Hi Maltes.

I think you need to make sure the broken vacuum pipes are repaired correctly, and not leaking air at all.

It also sounds like the carburettor mixture setting, (CO setting) is too lean. You could have it checked by your garage or try 1/4 turn clockwise on the CO adjusting screw yourself.

[maltes]

Good night G Force,

1. I bought bosch FR7DCX+ with a electrode gap 1.1
With these sparks, my car still pulling when the the throttle is completely pushed down (between 1500-2000 rpm) The funny thing is that up to 2500 rpm the car goes perfect. After 3000 km the spark plugs seem to be new.
2. I tested the car performance using old sparks Bosch FR7DC+ with a electrode gap 0.9. The problem of pulling seem to be solved but the car didnīt work ok.
3. I bought NGK BCPR6ES electrode gaps 0.9. I tested today and it goes perfect, I donīt know if it will last.
My explanation of that is that the electrode gap is the reason why it didn’t work. Do you think It is so important for the engine performance?.

Or May be the carburator is dirty?.

Thank for your help once again and regards

[G Force]

Good night G Force,

3. I bought NGK BCPR6ES electrode gaps 0.9. I tested today and it goes perfect, I donīt know if it will last.
My explanation of that is that the electrode gap is the reason why it didn’t work. Do you think It is so important for the engine performance?.

Or May be the carburator is dirty?.

Thank for your help once again and regards

Hello, I'm glad that your car is running perfect.

Yes spark plugs and spark plug gaps are very important, for engine performance.

I think if the car is running perfect you don't have dirt in your carburretor.

If you are worried or still not 100% happy, add some fuel system cleaner and some octane booster to your fuel tank, from your local motor accessories shop. You should also try driving your car more times in the month / year, and for more Km to keep good / new petrol in your petrol tank.

[maltes]

My problems with this car doesnīt solve. The car starts bad cold but then again started, if started well.

The car hits many pulls cold, but once warm and accelerate a bit after the engine runs well. On the road it is perfect.

I take mesuares resistor in sttepper motor and I obtain 15.7 ohms in all terminal, I think that this measurement is good. I suposse that finally the stepper motor works.

I have disconnect a Coolant temperature sender unit, if car is cold, it doesnīt starts. Then it starts well without coolant temperature sender unit.

Have you got any idea?. Thanks a lot for your help

[E_T_V]

Is the ORFCO valve disconnected and the wires taped up? If not then remove the valve - set it into the closed position and refit it but leave it disconnected. This can give running problems if it is sticking.

[maltes]

Thanks for you help.

I think, that my montego doesnīt have ORFCO, It is 1989. Fast check fuel magnament works in my car? I have bought, but I donīt Know if it works

Thank you

[maltes]

Then, Fast check fuel maganament doesnīt works in my car. I think that it is for previous montegos. Now I try to buy a microcheck. What is your advice....buy a microcheck to try if there is something wrong or buy a new manual choke carburettor.

Thank you

[Jeff Turbo]

Do you have a black ecu box or silver? If black you need a Lucas diagnostic Programmed Ignition Analyser. YWB133. That covers the coil, crank sensor, knock sensor and temperature sensor. There is a Fuel management Fast Check, SMD 4049 for carb models, that covers throttle sensor, coolant sensor, air temperature sensor, stepper motor, coil and solenoid. This unit covers the 1.6s series engine, Rover 1.6, Montego 2.0 and Turbo models and Rover SD1 2000/2300/2600 engines.

[Jeff Turbo]

These units are for a Montego/Maestro etc with a Lucas black ignition ecu

[maltes]

Thank you Jeff,

My ECU (MEQ 10060) Is silver, it has a 3 conector, I reckon that I need a microcheck but I don't know if it is better buy a microcheck (it cost a 250 euros) o to buy a new carburettor with manual choke ( it cost 400 euros) and I forget MEMS.

Now I have changed ECU for a new a it seems that car starts better.

Thank you very much.

[maltes]

First, then I have changed the ECU, car started better, but now it has the same problem. It ocurrs only when car it is stop for a day. The mechanic installed a non-return valve before the fuel pump, but it doensīt solve the problem.

Have you got any idea?. Thanks a lot for your help

[Doctordiesel77]

Might be worth trying one of these http://www.gunson.co.uk/product/G4074 it will not tell you exactly what is wrong, but will tell you whether it is lack of fuel causing the problem, when engine is cold it should burn with very yellow flame, if you see spark & traces of blue flame then there is not enough petrol, if you see spark and no flame, there is no petrol at all......colourtunes often turn up on ebay quite cheap, can save a lot of time in diagnosis as you can actually see what is happening...