high and low revs when cold (6 replies)
has any one had the same problem with there MPI,mine is a 1998 cooper,when cold engine revs say 2500 then down to 1500,if you try to pull off it tries to cut
has any one had the same problem with there MPI,mine is a 1998 cooper,when cold engine revs say 2500 then down to 1500,if you try to pull off it tries to cut out ,splatters for a while.once ticking over for say 3 mins you can pull of but a bit jerky,once warm problem goes.many thanks Bill
Hi Bill. When fully warm does the car run fine including tickover (750 to 850 rpm) and has it started to use more fuel and putting lot more rubbish out of the exhaust....my first guess would be the ecu in LOS mode for a sensor fault or at least a sensor running very poor, possible damage on plug....sneaky feeling its the air temp, but it needs all of them checking... (disconnect the battery before you start playing with it) start by checking that the wires aren't trapped or damaged
Many thanks mini7org,when warm it ticks over at about 800 revs runs great when warm,it only chucks out black smoke when cold,of you leave it to warm up a bit she's fine,but will go to minisport to have the ecu checked on there computer,i will keep you posted,kind regards Bill
Good info there Frank and others. Keep the rest of the MPI owning flock up to date please. Thanks
My 2000 MPi has had a couple of issues that may or may not be relevant. On M2L&B we had a misfire problem for a few days, as if the car was running out of fuel for a while, then would return to normal driving. This kept repeating. Only after I had removed the air filter housing and had a fiddle underneath did it stop completely for a couple of years!. Also, occasionally, and more relevant to your problem perhaps, when I start the car it idles at higher revs when cold but then instead of dropping back to 850 to 100 revs when cold the idle speed increases to 2000 to 2500. Only cured when I turn the engine off for a few seconds and re-start from when it is normal 850-ish again.
All this leads me to suspect the Idle Air Control Valve or the connection to it. When the car recently started to do the misfire again I repeated the air filter housing removal and fiddle operation. Noticed this time that some wires going to the engine relay box were rubbing against the wires to the air control valve, so added some insulating tape. Since then, no misfire problem except the fast idle once. So, maybe something to do with the connection to the control valve or maybe induced signal into the wiring loom hence affecting the ecu signals.
I came across an old handout from a show recently which advertised VmaxScart doing Rover Key Fobs but they also do ECU diagnosis so I plan to drop down there in the next couple of weeks to get them to have a look. They are in West Molesly (near Twickenham) so not far from me in Harrow. I don't want to change the control valve without getting it checked out first as they are Â£107 at MiniSpares!
I'll let you know if they find anything relevant.
Also check the engine loom for chafing where it is close to the Clutch cylinder! Been there, had that problem but the AA sorted it with 'experience!'