22 replies to this topic

[16v]

After much buggering about I cannot still get an SPi cooper I have to run properly.

Its rich, all the time, have had it plugged up to a the snap on reader, its bring up map sensor. You think easy, change the ECU and all will be fine. Changed it for an ECU that is perfect, still won't run properly. Earlier problem included a blocked injector, engine is brand new, basically done 15 miles at best. Injector is now changed for a working one, it now idles noirmally, but when you try to put it under any load when you drive it, it missfires. Compression is 190 across the board, but it will just not take full or even half throttle when you try to drive it. Any clues? theres no air leaks, map sensor pipe is unblocked, fuel pump runs ok, everything on the engine is new, dizzy cap, leads, plugs, everything! Plugs are gapped, take them out they are black. Lamdba relay is working ok, no other faults are being brought up by the readout machine. Anyone had this before?
Does it need resistor plugs as it has BP6ES's in it at the moment, (new), do I need BP6ES 'R's??

help!

Rich.

[Pavel]

Definitely sounds something fishy with a sensor. Could be a dodgy temperature sensor, or lambda sensor. These I believe may actually fail without bringing up a fault in diagnostics. Seems you've changed all the consumables and ruled out head gasket problems, so sensors seem the next step!

[16v]

Definitely sounds something fishy with a sensor. Could be a dodgy temperature sensor, or lambda sensor. These I believe may actually fail without bringing up a fault in diagnostics. Seems you've changed all the consumables and ruled out head gasket problems, so sensors seem the next step!

the lambda relay on the bulkhead is switching in an out, but I don't know if the sensor has failed. Although it idles, it idles quite low, 600 rpm, even on the very mild 274 Kent cam, its makeing the idler gear rattle a little.

The car was laid up over 5 years, first time it was started up it was all ok, and has just got progressively worse.

Its on an LCB, we plugged my supposedly "knackered" ECU into a perfectly healthy SPI, and it was fine, ran sweet as a nut. Coolant temp sensor is plugged in ok with clean connections I guess all it can be is the lambda. I'm sure the plugs would not make it run like this. but its very rich, fuelling is causing it to missfire all the way dwon the road, its virtually undriveable.

Rich

[pikey7]

call me silly, but if the diag says its a faulty map sensor, then have you tried changing the map sensor?

It sounds that way too. permanently rich meaning if the map sensor is down, it'll be assuming the air flowing into the throttle is totally wrong, and will compensate by richening it up.

[Sprocket]

Needs the stepper and idle air tunning to start with.

Is the ECU the correct one for the compression ratio you are running. 10:1 = ECU from cooper, 9.4 = ECU from spite or Mayfair.

Throttle position sensor can cause major problems with rich running. Temp sensors need to be checked against a calibrated thermometer. Use the Snapon to give you the information, it is than up to you to prove it one way or the other. Lambda sensor volts need to swing high low at least once a second between 0.2 volts to 0.6volts for it to be working correctly. Leaking exhaust manifold can cause rich running

My bet is its out of tune, and either coolant sensor or throttle sensor. Fit the right plugs NGK BPR6ES

call me silly, but if the diag says its a faulty map sensor, then have you tried changing the map sensor?

It sounds that way too. permanently rich meaning if the map sensor is down, it'll be assuming the air flowing into the throttle is totally wrong, and will compensate by richening it up.

OOh now that makes me think

Deffo sound like a MAP sensor issue

if the ECU works fine on another car, then the only thing it CAN be is there is a blockage in the capilary tubes and id suspect that one of the elbows has been pushed on way to far blocking its oriface.

Failing that, replace the lot from the manifold to the ECU including the fuel trap

It will still need tuning though, thats for sure

[beemerduck]

this sounds a similar problem I have now with my mpi !!

[Sprocket]

this sounds a similar problem I have now with my mpi !!

When was the Lambda sensor changed???

[beemerduck]

this sounds a similar problem I have now with my mpi !!

When was the Lambda sensor changed???

no idea ?!?! how much are they to replace?

[16v]

The fuel trap, and pipework is clear, one of the first things I checked. Both ECU's were from 1.3 I (10:1) coopers, even same reg (both 94, M plates).

The pipe work to both is clear, blow through the fuel trap and suck back through it and taste (yum) fumes. from the back of the manifold to the ECU is clear and not leaking.

I can fit the right plugs, but how do you "tune " it?

How do you adjust the throttle position sensor/Coolant temp sensor?

which is the colour wire on the lambda to make to take the readout off?

Rich

[Sprocket]

I suggest you go to the frequently asked Questions forum and look there

[16v]

from what I can understand there (past everyone disagreeing with everyone), I just literally reset the stepper motor by:

switching the ingnition to "on". Press my foot flat on the throttle and then off.

Reset the ECU.

Press the thottle pedal up and down 10 times with the Ignition on

Rich

[16v]

well neither worked, I just performed both operations and fired it up (the stepper motor reset itself, i heard it). From cold it was mega rich, black smoke and it stinks. It idles but rough and will missfire when you try to rev it at all.

why can't mems be like motronic? most motronic codes can be read by usinga paperclip in a certain plug, read off a flash code, it will tell you exactly which sensor it is, wether its high or low voltage (low usually indicatinga broken wire, high indicating a knackered sensor)

quality rover strikes again.

Rich

[16v]

right:

here goes, I VERY much doubt its the coolant temp sensor, as the temp gauge works accurately comes up off zero and will happily sit @ half or tiny bit below when warm. HAS to be:

lambda sensor/air intake temp sensor, OR map sensor. although even though the snap on machine bought up map sensor, why would plugging another ECU into it, cause it to give the same problems?

after reading the FAQ SPi page this is all I can think off, anyone else care for input?

Rich

[Sprocket]

Maybe the snapon reader is faulty?

[16v]

I dount it, its brand new, and cost in excess of £5000.

It doesn't matter now anyway, I've got someone to fix it hopefully, as I'm fed up with the rovers mems absolute and utter *******. Minis should have just been left on carburettors, with distributors, they are no where near advanced enough to need EFI at all.

Rich