7 replies to this topic

[andyboy!!]

Hi

I have a 1998 Mini Cooper.

I have been experiencing misfires for a while now. I have chaged plugs leads etc etc. It seems to be worse when accelerating\going up-hills\damp or cold weather. It also pops and the back sometimes.

It has got worse recently. I have been told it could be the MAF (mass air flow). Are these on this model and if so, where can I find it? It has been on diagnostics. The only thing that showed up was the ambient temp sensore which I have swapped with another mini. This made no difference though.

Does anyone have any other suggestions? Any help would be much appreciated.

Thanks very much.
Andy.

Edited by andyboy!!, 30 August 2007 - 11:28 AM.

[biggav]

MAP sensor (manifold absolute pressure) i think.

i think it woud be best if run on the proper rover diagnostic set up as that should give a better indication (i think)
where abouts in the country are you?

[andyboy!!]

Thanks for the reply

I was told it was MAF (Mass Air Flow) which measures how much air to draw into the filter? I'm no expert so I don't know?

I'm in St. Helens (North-west)

Ta. Andy.

[Ethel]

I think they are different things. Map is on the manifold, Maf is before the throttle body.

Find Taffy's thread on the MPI workshop manual or pm Juju, she downloaded them.

[Sprocket]

Thanks for the reply

I was told it was MAF (Mass Air Flow) which measures how much air to draw into the filter? I'm no expert so I don't know?

I'm in St. Helens (North-west)

Ta. Andy.

There is no MAF sensor on these engines

The method of air measurement is Speed density, this uses a combination of coolant temp, air temp and manifold absolute pressure (MAP) and engine speed. If the guy that was using the diagnostic said there was nothing wrong, he is not doing his job very well, i would go somewhere else. Its not the code reader that fault finds the engine, its the person using it. Bottom line is if its missfiring and the mechanic says there is nothing wrong because the code reader said so, then he doesnt know what he is doing in the first place, Take it somehwere else.

Sensors do not have to completely fail to cause major problems, if the temp sensors are reading several degrees out, especialy the coolant temp sensor, it gives the ECU the wrong idea of what the engine is actualy doing. These sensors need chaecking against a calibrated digital thermometer and the diagnostic readings, that is the point of the diagnostic, its a tool, not a magical box that tells you what to fix.

It would help to know what colour the plugs are after a run out in the car, thus telling us if its a rich missfire or a lean missfire.

Camco 88 in warrington is a Network500 agent, they should be able to sort you out with the diagnostics.

http://www.atpelectronics.co.uk/

[biggav]

What He said^^^^^^^ told you it was a map sensor.

[andyboy!!]

Thanks for your replies.

I was thinking of taking it to Camco.

Does anyone know where I can locate this sensor in the enigine bay?

Cheers
Andy.

[Sprocket]

The Map sensor is mounted on the inlet manifold on the right hand side as you look at the engine.

Id be getting the diagnostic done first before throwing parts at it, blind.

Im not convinced its the MAP sensor myself, but then i havent looked at it, just doesnt sound like a MAP sensor fault in what you describe.