Hello everyone,
I've got a strange misfire that I can not figure out, and I thought it would see if anyone has some ideas.
It is a 98 Mini with the MPI fuel injection.
The car has dead miss on cylinders 3 & 4.
Here is what I know:
I first replaced the plugs and wires because they were blasted out anyhow
Then I checked to verify that I had spark - I do on all 4
Then I checked my fuel injectors for power and ground - Noid light flashes the same for both injectors. So, I then switched the injectors to see if the misfire would follow, and it doesn't.
After that I did a compression and leakdown test, both passed perfectly.
So still baffled, I then removed the coolant temperature sensor and tested it - passes fine. Check IAT sensor - passes test. Checked TPS sensor - passes test.
What I found out then is that cylinders 3 & 4 are being heavily washed out with fuel. Both pistons are very much cleaner than 1 & 2, and when I unplug cylinder 3&4 injector the idle smooths out instantly, just for a few seconds until all the fuel is burnt up and then it resumes its misfire.
Any thoughts would be greatly appreciated. Thanks!

 

Usually a washed out piston top is due to a leaking head gasket and the coolant steam cleans the piston top. OR a washed out piston top due to too much fuel - stuck injector that stays open or no spark.

 

He said the problem didn't follow when he swapped injectors, that leaves only the head gasket or the possibility of a problem in the ECU, holding the injector open too much or too long.

 

do you know of anyone with a diagnostic reader which may help

 

OP does not mention where he is

but it is my understanding the scarcity of ECU diagnostic tools for the SPI/MPI systems on Mini in the U.S. is a strong reason for avoiding them

often this is about the time owners begin to consider changing over to a carb set up ....

there are kits available

as well as replacement ECUs

 

Changing an MPi to carb is a big job, no distributor so you have to change the ECU to an aftermarket.

I'm pretty sure a couple of the US Mini specialists have the reader and some electronic parts are available even here in the US, but depending on the OP's location it could be a challenge getting it checked out and fixed.

 

is this kit have all the pieces needed?

 

this can not be done on the MPi engine its possible on SPi s but still requires a lot of messing about

 

at that price you can pick up a good carb engine

 

Sorry for the delay in response. Still no new findings over here. Id love a scanner that could communicate with this thing. I've got a Launch system that has Rover as an option, but I don't know how to get into it - the model options for it don't seem to jive. Strangely enough is has no check engine light on......
Thanks for the help guys! Anything else is appreciated
I will continue to post if there are any other updates/findings.

 

You still haven't told us what part of the country you're in.....maybe we could suggest a shop if we knew where you were?

 

I have the ECU diagnostic for the SPI/MPI. What part of the country are you in?

 

Our Club clubbed together to purchase a reader cost £450 with leads and 2 cartridges...... http://www.ebay.co.uk/itm/SYKES-PICK...item2a8f132536 much cheaper these days