11 replies to this topic

[tattoo john]

Hi Guys,
Today i was meant to take my mighty mini for its second MOT after replacing the front panel (with oxy acetiline welding not mig) and a few little bits like brake lights.

The car started fine and idles fine but when i drive it the revs wont go past 3000 and it is coughing and spluttering and backfiring from around 2500 area.

i have not taken anything out of the ca or done anything to the engine, last time i drove it which was about a month ago it was fine and no problems at all. i have been starting the car up every week and let it get upto temp.

i did have a quick look on here but thought i would ask to see if it is something easy to solve?

thanks in advance and MOT no 3 will be the one!

John

[Sprocket]

Check all the little black pipes that connect the ECU to the manifold, discused and described a MILLION times. Failing that, if it is not the problem, check the throttle pedal switch on the pedal box inside the car. If it sticks, the symptoms are as you describe.

Dont drive it or you will melt the cat!

[tattoo john]

Cheers, i will check them out. i drove it for about 5 minutes so hope i have not melted the cat..

[tattoo john]

Hi,
We have replaced replaced the vacume pipes that connect to the maifold and ECU (3 pipes in total) and distributor cap and rotor arm and plug leads. the car starts fine and idles ok. but if you drive it slow it will rev all the way up but if you plant it then it coughs and splutters and does not want to go anywhere.
the fuel pump is making a high pitch whine..could it be this or is there anything else that it could be?
we have also checked the throttle pedal and that seems ok too.

Thanks
John

[Rented]

Sounds like fuel deprivation , the high pitch wine from the pump could be it starting to fail or that there is a kink in the fuel pipes somewhere , so as its trying to pump the fuel the resistance at the kink it making the pump struggle against itself . Just check the pipes under the car are not kinked / dented and also the rubber pipe from the fuel tank into the fuel filter at the rear subframe is not kinked ( Common when the pipe starts to degrade )

Edited by Rented, 11 October 2009 - 11:22 AM.

[Sprocket]

Does this car have the throttle pedal switch?

I mentioned it before, and you responded that the padal is fine. It is not quite clear if you understood what I was talking about?

Answer me this, does the ECU have one or two loom plugs?

[tattoo john]

Hi,
we have checked the ecu and it only has one big block plug. then chcked inside the car and followed the pedal to the manifold. there is no switch inside the car.
i cannot see any issues with the fuel line but will check or replace the fuel filter..
the car starts fine and will rev ok if you are really gentle with it but if you put your foot down it wont go and coughs and splutters still. we have taken the ecu off and placed in the airing cupboard for the night as well with some cotton wool in it.
i wish it would work so i could drive it! ha ha

Edited by tattoo john, 12 October 2009 - 04:15 PM.

[tattoo john]

here is my car by the way..it is work in progress..

 25082009050.jpg   616.5K   12 downloads
 25082009045.jpg   594.91K   11 downloads

Edited by tattoo john, 12 October 2009 - 04:26 PM.

[Rented]

smart motor !!!

Hope the running problems are sorted in time for the MOT

[Sprocket]

Well it could be any number of things.

Replace the fuel filter
Check that the MAP sensor is infact reading something and varies with engine condiitions(diagnostic connected)
Check the throttle position sensor is working (diagnostic connected)

There is not enough information to be going on with really.

Just be sure that you are using the correct ends on the capilary lines, as the short stubby ones used on the manifold, fuel trap and ECU will block the path giving false MAP readings, seen it done loads!

[CobraV8]

I would be pulling connections off at front and back of the car on the fuel line and checking that you can blow through it. Possibly replace the fuel filter, and failing that find someone with a fuel pressure gauge, and check what pressure you have.

[guusvandevelde]

I'm not saying that this is the problem with yours... but...

The dizzy on ours was out to the point where it had this same problem (bogging down on acceleration and didn't want to rev up.

I adjusted it a bit (little bit at a time) and revved it up. When it finally revved up nicely I tightened the adjustment bolt.
problem was solved...


My thinking on this: The electronic ignition advances the spark timing, but if the dizzy isn't at the contact point, no spark will go to the plugs.